Nephrologist & Kidney Specialist, Staci Leisman, M.D.

0:00 Hi, it's Doctor Robert Seikert with another great episode of Doctor Podcast. Thanks for tuning in. Today we have a great guest, Doctor Stacy Liesman, who is a nephrologist and an associate professor of medicine and medical education at the Mount Sinai Medical Center here in New York City. Thanks very much, Stacy, for coming today. We really appreciate it. I know you're very busy and been working hard all day. So thank you. Thank. You for having me, Robert. It's fantastic. It's great to be here. So, Doctor Liesman, you're a nephrologist.

0:30 Can you tell us what a nephrologist is and what that specialty is in medicine? Sounds great. So I never introduced myself as a nephrologist. Most patients don't know what it is. They've never heard that term before. Unlike our cousins, the cardiologists and the gastroenterologists, people just are not aware. I think that there's even doctors for kidneys. So I tend to introduce myself as, hi, I'm Doctor Liesman. I'm the kidney doctor, which tends to be at least understood by most patients. But the funny part is that although I am a kidney doctor, I take care of many more things than just people who have problems with acute kidney disease or chronic kidney disease.

1:10 The kidneys control the levels of many of the electrolytes in the blood. They have a very important role to play in blood pressure. So many times I'm called to see patients who may have levels of potassium in their blood that are too high or perhaps problems controlling their blood pressure. And I have to be careful. In fact, this week I walked into a patient's room and said, hi, I'm the kidney doctor. And I saw the patient's mother. She was pretty young, you know, look stricken, right? And I said no, no, no, everything is fine with her kidneys.

1:40 They called us to see her because she had a problem, actually, with the acid base status of her blood. And so we helped take care of that. That's very interesting. How did you become interested in kidneys or nephrology? So I'm always a person who loves puzzles and chemistry and math and kidneys really allow you to explore those interests. You know, I can look at a bunch of labs and and diagnose a patient, you know, with a combination of labs, with a combination of of history. It feels like solving a puzzle every day in terms of diagnosis, in terms of treatment, and we have great patients.

2:16 You know, kidney disease strikes everyone. It affects the entire body and you're really trying to solve mysteries everyday, which really appealed to me. Right. As you know, I'm an ophthalmologist, but I almost became an nephrologist because I was always fascinated by what kidneys do in the body. They interact with every other organ in the body and have all sorts of mystical qualities. They control lots of your body functions. People don't know that, so most people don't even know where the kidneys are.

2:49 Can you tell us how many kidneys are there and where are they located? Well, like you, I take care of people with two organs, right? You take two eyes, I do 2 kidneys. So the kidneys are in your back. They're, you know, right about here in your lower back and they are about the size of your fist. So what that means is if you were a big person, that your kidneys larger than if you're a smaller person. So you can figure out the size of your own kidney by looking at your fist. Some diseases will make the kidneys bigger or smaller and we can use that to help diagnose kidney disease.

3:20 I will say that we were looking at this picture before. Kidneys do not look like that. That is not a an accurate rendering of a kidney. Well, in the future, when artificial intelligence takes over medicine completely, it will create new electronic kidneys that looks something like that. I will say there's a huge shortage of kidneys for patients who need them and if we could develop fake kidneys that would be absolutely fantastic and change a lot of lives. You mentioned that people can get kidney disease where the kidneys don't function properly.

3:51 What symptoms might a patient have who has kidney problems? So the challenge with kidney disease is is people with kidney disease often have no symptoms until it's too late. The major, the major factors in kidney disease in this country are diabetes is the biggest risk factor, having uncontrolled diabetes and hypertension, which is a little bit in question because hypertension is sometimes a chicken and egg phenomenon. The kidneys don't work, which gives you high blood pressure, which then causes more kidney damage.

4:22 And what I like to tell patients is it's really not until you get about 30% of your kidney function that you may start feeling symptoms. And those symptoms might be swelling. It might be you're anemic or have a low blood count. And then only when it's really about 15 to 20% of kidney function will you start getting symptoms like itch or having trouble sleeping or having a funny taste in your mouth or nausea or fatigue. But in that sweet spot of where you have disease and we can maybe make an impact, you will not have symptoms.

4:56 So it's really important for patients who are at risk for kidney disease. So patients with diabetes, patients with a family history, patients with hypertension that they do get their kidneys checked out at least annually, so we can catch disease before it starts and try to make an impact and try to slow that progression down. Now they're just a few simple blood tests that can be done right. They're kind of routine blood test to check kidney function. Can you tell us what those tests are? Sure. So the main standard chemistry that most of us get if we go to the doctor contains 2 numbers that I will look at.

5:32 The 1st is the BUN or the blood urea nitrogen. Sometimes it's written one of two ways. My patients call it the bun test. You know what my medical students do as well? And then I say don't call it that, call it BUN. Otherwise people will laugh at you on the words. But the BUN and that number is helpful. When that number goes up, that's not a good thing. And the other number that's more important is the creatinine. So most people will have a creatinine of about 1 milligram per deciliter and it goes up.

6:04 And so, you know, patients often don't know if numbers that are high or bad or numbers that are low or bad. Really, it depends on the number, right? So in this case, when those numbers go up, it represents the accumulation of toxins in the blood. It's telling us the kidney is not getting rid of what it should get rid of, and those numbers go up. And the other big test that we like is a urine test, which nobody minds right, Because you don't even get stuck for that, right. And so the things that we will look for in the urine are sugar for patients who have diabetes and.

6:35 Normally there shouldn't be sugar. There shouldn't be sugar. If your sugar is high, it's a great screening tool. You know, for diabetes protein. So the kidneys are filters and big things shouldn't get through your filter and small things should get through your filter, right? So protein in your body is considered a big thing, and if those small, delicate vessels get damaged and protein starts to come through them, the filter gets too leaky. You can see protein in the urine and sometimes blood. Although blood in the urine doesn't always mean kidney disease, it's.

7:12 Bladder or other? Problems, I mean, and if I have a female patient, it's menstrual blood is going to be your most common cause of blood in the urine. So that one doesn't worry me as much depending on, you know, who the patient is in the right context, a high creatinine and blood then we do think primary kidney disease. Right now you mentioned toxins in the blood. The main function of the kidneys is to clear out those toxins in the blood, right? Yeah, that's right. Where do they come from? Those toxins?

7:40 Why are there toxins in the blood? So that's a great question. So why should there be toxins in the blood? And the main place those toxins come from is not things that we think of as toxins, it's food and cellular metabolism. So your cells are constantly in a process of of turning over, regenerating and every day we eat and what we are, why we are lucky to have the kidneys. I tell students, I teach a lot of students is is kidneys allow you to eat a varied diet. If we didn't have kidneys, if we had a system where every day you get rid of 20% of the potassium you ate and 20% of the sodium you ate and a liter of water, well, we would have to eat the same exact diet every single day, right?

8:27 But what the kidneys can do, what's so amazing about the kidneys is they can sense what these various levels are of substances in your blood, potassium, sodium, water, and make a decision. If we're going to keep it, we're going to get rid of it. We don't need it. Other toxins come from. Generally our blood needs to say at a particular pH, so the pH of water is 7. The pH of our blood should be 7.4, so it's. That determines the acid or base of. The of the blood. So you know, just like you know, blood is thicker than water.

9:00 Blood is also slightly more basic than water at 7.4, and we eat a lot of acid. Many of the foods we eat contain acids in the form of amino acids, protein in particular, and as we break those down as we digest them, as we use those products to build new cells, it can change the acid base status of the blood, and so the kidneys are used to make sure everything stays. The big word we use is homeostasis. We stay exactly as we should be. That's pretty amazing. It's almost like the kidneys had a little built in brain and they keep track of just about every chemical in the body.

9:35 And if you've got too much of it, the kidney dumps it into your urine, You don't have enough of it. The kidney kind of holds on to it, puts it back in your blood, So and it's all in real time, right? It's all in real time. It's happening on a second to second, moment by moment basis. We like to say there's a the reason that there is a an artificial heart is because the heart is simple. It's a pump. There's no artificial kidney because it's so difficult to make an artificial kidney. It's it's so specialized and amazing in what it does that although we keep hearing you know in the next five years we're going to get an artificial kidney, it's near impossible to do because of of how incredible the kidney is it.

10:16 The number that I tell students is to get a sense of how incredible the kidney is, is the kidney filters 180 liters of blood per day. So if you can't wrap your head around 180 liters, think about those huge garbage cans that you know, you rake the leaves and you put into the that's about 180 liters. And that is the amount of blood your kidney filters every single day in a healthy kidney. Or about 180 water bottles a day, right? That's going through the kidney. Kidney keeps track of everything in there.

10:49 Yeah, it's unbelievable. So basically the toxins are metabolic products of of food. We right the the food is used, obviously to keep our bodies healthy, but in the process there's some toxins created and the kidney dumps them into the urine. That's right. And so when your kidneys don't work, one of the things we have to talk to patients about is limiting certain, you know, the quantities of certain foods they eat. So a a big thing we tell patients is potassium can be deadly to your heart and they have to eat a low potassium diet, which can be tricky for many, many patients.

11:23 Right. The kidney keeps track of potassium and sodium and tries to keep it at a normal level all the time, regardless of what you eat. And you mentioned blood pressure. The kidneys also control your blood pressure to a great degree by releasing various chemicals into your blood. Is that right? That's correct. So, so the kidney, because the kidney is seeing so much blood, it's a great place to put a sensor for what your blood pressure is. And if your blood pressure goes down, it says up blood pressure is too low.

11:55 I'm going to release a a chemical, it's called renin. And that triggers a cascade of effects that that tells the kidney to hold on to more salt and water. And when you hold on to more salt and water, when you basically don't pee it out. If you're a nephrologist, you say pee maybe every third word. In my days I used to call it urinate. Now it's different. Well, we call it we in. If I'm being official, I will call it urine, but if I'm with a patient, you know. All right. We say pee. My kids think it's very funny.

12:29 So, so if you are, if your blood pressure goes down, we hold on to more of our salt and water. And if your blood pressure goes up, or if you eat a very salty diet and your blood pressure goes up, then the kidneys can get rid of that extra salt and water to bring the blood pressure down and. It all happens very quickly. It all happens a lot of knowing. Yeah, instantaneously. That's that's pretty amazing. Patients often have my patients tell me they've had urinary tract infections and occasionally they tell me that can spread to the kidneys.

13:02 Is that a a common problem? So it's not a common problem. If we think about how common urinary tract infections are, the number that spread to the kidney is, is very rare. So the urine goes into the bladder and the ureters, which actually, well in that picture there should be two there's there's one sort of trunky ureter, but the ureter. 'S AI. That's the AI version. The ureters go into the bladder and it's a one way valve. So the the the sterile urine from the kidney goes into the bladder through a one way valve which then closes.

13:36 And so in the bladder the urine should still be sterile. Obviously there's a tube that leads from the bladder out to the world and the the urothelium, the the cells that line that urethra have various substances that can keep bacteria from going up, right? Every time you pee you're pushing that bacteria out, right? So that system works pretty well and most people don't get urinary tract infections. If you do have an introduction of bacteria into the bladder, then you can get a urinary tract infection.

14:10 But because of the one way valves, it doesn't tend to go back to the kidney. It tends to stay there. Sometimes if a patient has instrumentation or they have a stent in the ureter or they have kidney stones, then the stone can get infected and then we can see kidney, actual kidney infections. But unlike A urinary tract infection, which is terrible, I mean, I'm not going to dismiss those symptoms. It's very painful, but you're not that sick. But with a kidney infection, which is called pyelonephritis, people are very sick, very high fevers, exquisite tenderness in in their back where the kidneys are.

14:49 Yeah, their lower back where the kidneys are. And those patients are quite, quite sick and often need IV antibiotics. So fortunately that doesn't happen too often unless there's some sort of blockage or or something like that. We talked in previous segments that I've done. We're always talking about diet and exercise and the importance of that to keep healthy and prevent lots of chronic diseases. What role do diet and exercise have in terms of kidney health? So I'm not sure if studies have been done on kidney health in completely healthy people, but certainly we know in patients with what's called chronic kidney disease.

15:24 So these are patients whose kidneys are not functioning at 100% that a diet enriched in fruits and vegetables can be protective. We also know that exercise can be protective as well. Whether that exercise is directly protective of the kidney or it improves your blood sugar, improves your diabetes, improves your heart, I'm not sure which of those effects is mattering more, but certainly we recommend you know patients exercise and and eat a diet higher in fruits and vegetables. Yeah, that seems to be the case to prevent all sorts of diseases.

16:03 So it works for kidneys as well. Now the kidneys interact with lots of other organs directly or indirectly, like with the heart. What's the association between the kidney and the heart? So that's a great question and and certainly one that there's been a lot of research on recently. So many of the diseases that damage the heart, high blood pressure, diabetes will also damage the kidney. But what we see is that the kidneys can be a little bit finicky and if they, they want a very particular amount of blood.

16:33 So when the heart can't pump blood as well and blood is backing up, you may have seen it. You know, patients will have swollen legs when they have what's called heart failure or CHF, congestive heart failure. It can back up into their lungs, but it and they tell you they're short of breath, but it can back up into the kidneys. And when it backs up into the kidneys, patients won't have any symptoms. But that higher pressure backing up into the kidneys prevents the blood from flowing in as well as it as it should.

17:07 And so we do see some decreasing kidney function as a result of when a person's having like a heart failure exacerbation. But I would say the biggest place we see it is that it's all the same players, right? Diabetes is messing up your heart and messing up your eyes, as you know, and causing damage to the kidneys as well. So the kind of work in a partnership, the heart has to pump enough blood into the kidneys to keep the kidneys happy. If the kidneys don't get enough blood, it kind of backs up into the system, which then adversely affects the heart because the heart can't pump all this and.

17:44 You can't get rid of your urine, right? So that fluid builds up even. More. And then you get swollen legs and then it backs up into your lungs and and you get difficulty breathing. So that's pretty fascinating. What about the brain interactions between various hormones and chemicals? Between the kidney and the brain? We don't see that as much. I would say the place we see it the most often is if the kidneys are very damaged and really not getting rid of those toxins the way they should. Those toxins can cause people to become very, very confused and and it can be difficult because unless we can get their kidneys to function better, either because we heal their problem or we put them on dialysis which is an artificial way of providing kidney function.

18:32 It can be challenging to figure out if the person's mental status changes, or because of the build up of toxins, or because of something more systemic that's causing the kidneys not to work also, right? So that can be a puzzle sometimes. Yes. So you have to do lots of different blood tests and scans to figure out what's going on. One of the most fascinating things to me is the interaction between the kidney and the bone marrow. The kidney actually tells the bone marrow how many blood cells to produce.

19:02 Can you explain that? Yes. So the bone marrow makes lots of blood cells, but the blood cell we're talking about here is the red blood cell. And the job of the red blood cell is to transport oxygen all around your body. So when you have more red blood cells, you are able to transport more oxygen. And like everything else we're going to talk about today, the the body wants to keep the amount of oxygen, the amount of red blood cells it has at a stable level and those red cells turn over. The lifespan of a of a red blood cell is not infinite.

19:35 They turn over. So we're always telling our bone marrow to make more red blood cells because red blood cells are dying and we're trying to keep ourselves in equilibrium. So how the kidneys play into this is parts of the kidney deep in the kidney is one of the areas that gets the least blood. It just so happens that way. So if you were going to design a system where you wanted to put the sensor to figure out how much oxygen your blood can carry, how many you know is your blood deficient in oxygen?

20:06 Where would you put that sensor? Well, in the place that gets the least amount of oxygen. So there's a sensor there in the kidney, and when it detects the oxygenation is too low, it assumes the oxygenation is too low because there's not enough red blood cells, and it produces A hormone called erythropoietin, which then circulates to the bone marrow and tells it to make more red blood cells. Now most people don't know about that hormone, except if you watch cycling, because that is a hormone that we can make synthetically, and it's called EPO or EPOGEN, and that's the hormone that gets athletes in trouble.

20:42 Lance Armstrong, I'm dating myself, was probably the most famous athlete to get in trouble for doping, but that is the doping they're talking about. You inject yourself with synthetic erythropoietin, you tell your red cells to make more, you tell your bone marrow to make more red cells, and now you have a much higher oxygen store to win the Tour de France. Right. Yeah, he was well known for that. Now the legitimate athletes actually practice and train at high altitude where their oxygen levels are low and so their kidney tells their bone marrow to make more red blood cells cuz they're at high altitude.

21:22 And then when they come back to normal altitude they have extra low blood cells. That's legal and legit, but injecting EPO is is not legal and legit, but that's well. For sports, it's legal because I do it to my patients, right? Well. Obviously. It's it's considered doping in sports, but my patients who don't have kidney function right can't make that hormone and we can replace it. Yeah, they become anemic. They have a low blood count. So it yeah, it's legitimate for patients, but not for. World class athletes.

21:50 Right, exactly. Now one of the exciting things about kidneys is their new medications that are available to treat kidney disease and CKD chronic kidney disease. It's called the SGLT 2 inhibitor, which is a tongue twister. But I'm sure you say it many times during the day. Can you tell us what that is, the SGLT 2 inhibitor drugs? I can. So I will say this has revolutionized the practice of nephrology because for the last, you know, you would tell your patients who have chronic kidney disease and maybe have kidney function at let's say 70% of where it should be, control your blood pressure, control your diabetes and that's all we had.

22:32 That's not doesn't feel very good, right. When you're talking to a patient maybe 2025 years ago, a class of medications came out called the ACE inhibitors that when we gave them to patients slowed down the progression of kidney disease. So we were excited Most of our patients ended up on, on these ACE inhibitor drugs, although that only worked in a particular type of kidney disease, kidney disease where where you also spilled protein in your urine and that's all we had for like 2025 years and probably in the last five years there was a revolution with these SGLT 2 inhibitors.

23:08 Now diabetes is an epidemic, and there's always looking for new ways to treat diabetes. And what we know is, as we talked about, the kidneys absorb lots of the things you should keep. And one of the things you should keep is glucose. So when glucose or sugar is in your urine or it gets filtered, the kidney absorbs all of it. So that's how we know because why you see when you see sugar in your urine, what that is telling us is that your sugar is so high that your kidney was overwhelmed. So when you have a normal amount of sugar, your kidney could absorb all of it.

23:51 And when your sugar is too high, then you overwhelm those those transporters, those little bits on the cell that absorb molecules and you see it in the urine. So what this drug did, it was designed as a diabetes drug was it inhibited the SGLT 2 transporter. So what the SGLT 2 stands for is the sodium, that's the S, glucose, Lt. that's something transporter, luminol, maybe luminol, transporter 2 type 2, that's the two. So it blocks this transporter that absorbs glucose in your kidney. And so you can imagine if you were an endocrinologist or that would seemingly be a great drug, right?

24:36 You instead of reabsorbing the sugar, you're peeing it out. And that would lower your blood sugar, right? It did lower your blood sugar, not to a tremendous effect, but it lowered your blood sugar. But what they started noticing was that in patients who were taking these drugs, they were having less heart failure or even sometimes like a regression of heart failure. And it also looked like their kidney disease was progressing more slowly. So then they started testing it in patients this hypothesis.

25:09 So they first started with patients with diabetes and protein in their urine and gave it to a tremendous number of patients. This was the the credence trial which stood for can of I have trouble with the word to can of flows as in I believe is how you say it, they all end in flows in these generic names and what they found they had to stop the trial early and the you only stop the trials trials early for two reasons. One is the drug is really dangerous, right? And one is the drug is so effective it is unethical to continue giving certain patients a placebo.

25:41 And so it was the latter. So it was so effective, they stopped it after about three years that they said we can't do the trial anymore. And they estimated that for a person who was maybe in their 60s with like moderate kidney disease, it would give them an extra 15 years before developing the odds, such severe kidney disease that you would need dialysis. So game changing. So they first started in the patients with diabetes because it was a diabetes drug and I think they were afraid to try it in a person without diabetes, would it 'cause their blood, right?

26:17 Because would it 'cause their blood pressure to drop too much? I mean not their blood pressure, so their blood glucose. Right. But they did it anyway and it turns out again, the progression of kidney disease was slowed down. So we now have these drugs and that's why it's so important to get screened because we now have something that we can give you that will stave off the, you know, the development of severe kidney disease so that you can live your life never needing dialysis or kidney transplant.

26:49 That's amazing. It's incredible. Yeah. I mean, it was, it's recent. It was when we go to our big national conference, there's usually like very little to get super excited about. I mean, that year that was all anybody was talking about because we had. But we had something. We finally had something. Wow. You know, to to make people's lives better. So these drugs, the SLGT 2 inhibitors, treat diabetes. They also treat kidney disease, even if you don't have diabetes. And as a result, it also benefits the heart.

27:23 I believe it's independent effects on the heart. So patients without kidney disease who have heart failure are also given these drugs. My guess is that this is a diabetes drug that fewer endocrinologists prescribe. Nephrologists and cardiologists prescribe it because it's that game changing for us, whereas for them it's not as game changing. It helps, but it doesn't help. Like some of the others, they have other tools in their shed, right? We don't. So I've seen ads a lot on TV for Farxiga and Jardiance.

27:54 Those are the two I see. Those are the two, yeah. But there's some other ones, right? Are they different or are they similar? They're all pretty similar. I think they're all very expensive and so it generally it's whatever one your insurance is gonna cover. There's been a lot of different trials. Each drug company puts their own drug in a trial, and they're they're all showing pretty similar effects. I see. Have there been any head to head comparison trials? Or oh, they'll never be that one, because then some some drug companies go lose out and they're never going to want to sponsor right, anything that will make them lose out.

28:23 And they're not available generically. Yet, unfortunately, no. They're very expensive. They are what's very expensive. So my parent, Well, my, I don't know how much they are if you have no insurance, but I can tell you that my dad is on Jardiance. Hi, Dad. If you're watching. Really. Hi, Mom. I'm not sure. My dad's probably asleep by now, but he takes Jardiance for heart issues, and he's on Medicare. So he has the Medicare drug plan. And I think it's about 300 a month, all right. So it's. It's it's a big deal.

28:57 Medicare. Yeah. So without. It That's his copay. That's his copay. Yeah, without it, it would be much more expensive. Hopefully they'll come out with generic versions that are less expensive soon. Now. There are other categories of drugs, which I'm sure you've seen Ozempic and Wugovi and also Munjaro that are for diabetes. And recently I've seen data that they also help heart disease and they may also benefit kidneys as well. What's the difference between that category and the one we just discussed, the SGLT 2 inhibitors?

29:31 Yes. So I think for the SGLT 2 inhibitors, it, it made more sense that a drug that's acting on the kidney could potentially improve the kidney function. And there's a variety of reasons that we think it does this. We don't actually know the the true mechanism. One theory is that this is a transporter that needs to use some energy to absorb the sodium and the glucose together, that by turning that transporter down a little bit, the kidneys wasting a little bit less energy or using a little bit less energy.

30:03 There's some thought about, it's a little bit complicated technical talk. But because you now have more sodium and glucose later in the in the nephron in the kidney, that the kidney thinks it's getting way too much blood. So it it tries to slow down the amount of blood that it's getting or limit the amount of blood that's getting, which turns out over the long run to help the kidney. That one, that one, it made sense, these drugs, these new blockbuster drugs that it feels like everyone's talking about.

30:32 Also diabetes drugs and those drugs, I think it's similar idea, we don't, they don't act on the kidney at all. So it's not a direct effect on the kidney. The thought is that they are reducing inflammation overall or perhaps this metabolic state. This metabolic when you have a lot of metabolically active fat tissue, it can cause high inflammation and this high inflammatory state is probably bad for the heart and the kidney. So the thought is, is as you reduce the amount of adipose or fat tissue you have in your body, you can reduce some of the inflammation and then that might be what's good for the heart and the kidney.

31:16 So if you take Ozempic and Farxiga and exercise and have a reasonable diet, you should be able to live forever. Yeah, live forever and also an ACE inhibitor. You don't want to forget that the old our old friend. The ACE inhibitor, it's it's generic. So yeah, yeah, ACE inhibitors also reduce heart complications. That's pretty fascinating. You have published some literature and medical literature about COVID effects on the kidneys. Can you tell us a bit about that? So I just want to point out that that was a very big group effort.

31:49 It was during the pandemic Mount Sinai as being in New York and while you, I'm sure the same way, was impacted dramatically by COVID, We had tons and tons of patients and I think what we were trying to do is is you know make something positive out of something very negative by trying to publish our experiences. So you know that it, it was very interesting actually because the original rounds of COVID were causing so much kidney failure. It was it was nearly impossible to dialyze all of the patients who newly developed kidney failure from COVID.

32:26 And I don't know if it's the vaccine or or the steroids we learn to give people or it's a different strain of COVID, but we are not seeing the same degree of kidney failure or kidney damage with the newer strains of COVID. There's there's evidence, you know, very conflicting evidence. Some say COVID, it infects the kidney cell directly. Some say it doesn't. We're not really sure. I don't know. But we thankfully are not seeing as much kidney damage from COVID as we as we had in spring 2020. Yeah, the virus seems to have evolved to a less severe type of virus, which makes sense because it wants to keep its host alive, right?

33:09 So that it can duplicate. Well, that's good news. Now, you mentioned dialysis and dialysis. So dialysis is when the kidneys are no longer functioning adequately and medications don't work anymore. Can you tell us what the dialysis process is? Sure. So dialysis is other name is kidney replacement therapy. So the idea is that the kidney has all of these functions and we can have a way to try to replace some of those functions. Now we can do medicine. We talked about you know the the EPOGEN or the erythropoietin that we give people, we can give medicines to try to make them urinate and so to try to get some of the fluid out that way.

33:51 But eventually you reach a point where you can't get rid of the toxins and or you can't get rid of the excess fluid and we have to do kidney replacement therapy or dialysis. Now dialysis is a mixed bag. Nobody wants to be on dialysis. But I do tell my patients, you are very lucky that we have dialysis because if your liver was this damaged, we have nothing. It's a transplant or nothing. If your heart is this damaged, there are things we can do, but many of them require you to live in the hospital or have a big device attached to you With kidney replacement therapy.

34:29 With dialysis, you can most of the time be OK except when you are on dialysis. So there's two main types of dialysis that we do. One is we take blood out of a patient and we run it through a a machine that cleans it up, cleans it out and then we put it back into the patient. So the machine clears out all the toxins that normally the kidneys would do. Normally, right? But as I tell my patients, it doesn't give you a completely normal life because our kidneys work 24/7, right? For these patients, their their kidneys only work when they are physically attached to the dialysis machine.

35:06 And so how many hours a week do they have to do that? Or how many days a week? So for most patients on hemodialysis, this is the type we're talking about. It's 3 1/2 hours, three times a week, So a very different amount of time than a person with normal kidney function. There's another type of dialysis that patients can do at home. It's kind of less well known. It's called peritoneal dialysis and this dialysis is is quite ingenious. You instill a fluid in someone's belly, and there's so many blood vessels in the belly that with this, basically it works by diffusion.

35:43 So the idea is that toxins that are in the blood that are not in this fluid move into the fluid. And things that you want to give the patient, you enrich the fluid with. So those things move into the patient in their bloodstream. And then after a certain amount of time, you drain the fluid and then refill it. And so this process allows you to clean the blood and remove fluid from the patient using a bloodless system. And what's great about this system is you do it at home. So it's most nights you would do this at home, usually seven nights a week.

36:16 And then you can live your life, you can travel, you can, you know, people will ship these bags of fluids to Florida and they can do it in Florida. There's cruises where you can take cruises and. That's an amazing. It's amazing. It's amazing. Not a lot of patients opt to do it and there's a variety of reasons for that. As we know, diabetes is the number one cause of kidney disease and it affects your eyes. And so if you are blind, which unfortunately many of our patients are, many of my patients have amputations which might prevent them from doing the setup they need to do at home.

36:49 So not all patients can do this, but it is a big push to try to do more home dialysis to give patients some freedom back. Do you work at the Mount Sinai dialysis centers? I work at dialysis center. I take care of 20 dialysis patients. They're my patients all the time. I see them once a week, right. And it's affiliated with Mount Sinai, but it's not owned by Mount Sinai. Many dialysis units are owned by a corporation. I see. And the physicians, the physicians come in, Yeah. What's your day like, by the way?

37:25 Every day taking care of patients and and what do you do? So I have a fantastic day because it is different every day. I think I would get very bored if I did the same thing every day. So I have I guess 3 three to four big roles that I do on a year, let's say yearly basis cuz each one kind of peaks at different times. So right now I take care of patients with kidney disease who are in the hospital. So all day long I spent taking care of patients with a variety of either kidney disease or electrolyte disorders.

37:58 I see them, I make recommendations and then when they go home, I hopefully as I tell them, you're lovely, I never wanna see you again, right. Cuz if I'm seeing you again, you're in the hospital. So basically these are people in the hospital for various medical surgical conditions and they happen to have kidney related problems. So the doctors call you in as the consultant that's correct to help with the kidney problem. That's great. So that's one part of my job. Another part of my job is as an outpatient dialysis physician.

38:29 So these are the patients I see once a week. They are mine forever. I mean hopefully. And I go to this unit, this dialysis unit that's on 105th, 106th St. and see my patients. And because I see them once a week, it's actually fantastic. Most of the time we don't talk about their kidney problems. Most of the time we talk about their grandchildren, you know, their hobbies. You get to know them very, very well. I've been to patients funerals because I've gotten to know them very well. And when they have problems, I get called about them during the week.

39:05 You know, this patient ran out of this medication, a simple problem or this patient, you know, has really high blood pressure. What should we do? Those are, I think, the jobs that people associate a doctor as doing. But I also have a very large role in the medical school at Mount Sinai. It started off with running the Physiology course. So as you can see, I'm excited about how things work. And so Physiology is how things work. So every medical student in their first year has to learn how the body works.

39:35 That was my favorite course in medical. That's a great course. You find out how, everyone. Feel like a doctor, right? You understand it. And, you know, if you're a patient, it's probably nice to hear that we do learn how the body works at at some point in our career, right? So I run that course. I I end up teaching human Physiology. So I teach a lot of the heart, how long I teach, all of it. And then as a result of that role, which I really loved, I ended up applying for another position within the medical school.

40:06 And so I oversee the entire 1st and 2nd year curricula for all of the medical students at Mount Sinai. And so a lot of my role is figuring out policies, you know, advising other teachers or course directors on how to run their course, thinking through. The future of medical education, we're about to undergo a massive revision of our curriculum and redesign of our curriculum. So, so planning that, thinking that through, bringing the people on board, doing a lot of that work. So it's very creative and fun.

40:39 Yeah, I noticed your associate professor of medical education at the ICANN school at Mount Sinai. That's great. How has medical education evolved over the years that you've been doing this? I I think we have come to terms with the fact that we are never going to teach our medical students all of medicine, and I think in the past there was a lot less medicine to teach. Most people were generalists, right? You were either a general surgeon or a General practitioner. I'm not really sure how ophthalmology would fit in there, but well.

41:13 In the old days, ophthalmology was combined with ear, nose and throat. Yeah. Steve. Basically the doctors were called eye, ear, nose and throat and then eventually it split up because there was just too much information and the surgical procedures were were too varied. Now I only take care of patients right Eyes by the way, not just joking. Take care of both eye. But just the front of them. I do just the front of the eye, that's. Correct. So, so recognizing that we are never going to teach every medical student everything, and that as they move forward in their career, probably the best skill we can teach them is a sense of how the body works, right?

41:55 A sense of the Physiology, a sense of the a sense of the diseases that all of them are going to see, right, No matter what kind of doctor you are. But most importantly is teach them how to learn on their own. How do you have a patient tells you something and you've never heard of that? How can you learn about it? How can you understand what's important? How can you? Teaching students how to learn how to be independent self-directed learners becomes much more important than teaching them medicine that might be obsolete in five years.

42:26 So recognizing that and recognizing how people are going to sub specialize, it didn't make sense anymore to spend 2 years half of medical school teaching a cookie cutter one-size-fits-all medical program medical curriculum. It makes a lot more sense to teach them the basics. Have them learn how to figure things out. Have them learn, you know, the most common, most important diseases instead of all these, you know, we call them zebras, right? Instead of all of these really rare diseases they're never going to see and do it in a shorter period of time.

43:04 So rather than spending two years learning one year everything normal about the body, right, a normal anatomy, normal Physiology, and year two, everything that could go wrong with the body. So of course on everything that could go wrong with the heart or everything wrong with the lungs, we're going to integrate it, which allows us to cut the time without cutting the content. So on you may walk in and Monday you dissect the heart and then Tuesday you learn the Physiology of the heart. And then Wednesday you Start learning the some of the diseases of the heart.

43:38 So an integrated curriculum, a shorter integrated curriculum. We at Sinai are moving to 18 months NYU where where you're from has moved to one year of that shortened pre clerkship curriculum and then a year of clerkships, right. Every student needs to know something about everything. And then the last 18 months allow our students to specialize. So I'm nephrologist. I do not care about hips. I do not care about bones, but my friendly orthopedist really does. So maybe have in that last part, they do an elective where they do intense skeletal anatomy and I'm going to go into internal medicine.

44:20 So maybe I take an advanced Physiology course. And wouldn't that make a lot more sense for what we are choosing to do? And so that's kind of the future of medical education. And I think another huge piece is recognizing we work in teams. We rely on many other people. It's not just, you know, one doctor in an office running the show. We rely on Patients are much more complicated. Many of them can't go home. We work with social workers closely, nurses closely, learning those team efforts, learning how to work with other people, learning what other people do and and how every job is valuable.

44:57 You know, learning those types of things become super important. Yeah, it's very different. When I went to medical school, first couple of years were just didactic lectures basically there was no patient exposure. It was just going to lectures and learning what you said. I think the this new evolution is more logical and makes more sense and will make better doctors in the future. So that's great. We talked about kidneys and dialysis. What? What about kidney transplantation? That that's a common thing in the news?

45:34 So kidney transplantation is actually and I should have said this before, the best way we can take care of somebody who has end stage kidney disease when their kidneys don't work. That is what we want all of our patients to have as a transplant. The problem is there's a shortage of transplants and and sometimes the problem is many of these patients come to us late and because they're coming to us late, then we don't have the time to set them up for transplant, A preemptive transplant. So should we pause?

46:03 I don't know where that's coming from. We can continue, OK, just ignore the. BP OK, so kidney transplantation is what we want all of our patients to have. But the problem is there's a shortage. And there's a shortage for a lot of reasons. I just took care of a patient today. He's 42. His kidneys don't work and you know he has a he has a family who clearly adores him. I've spoken to the sisters on the phone but when I said do you have somebody who could donate a kidney, they were got very sad and said we really don't.

46:39 So many of our siblings have kidney disease. We can't donate a kidney because kidney disease has has a genetic component. So we rely a lot on on people who are altruistic. Either they are altruistic and donate a kidney to someone they don't know, or who choose to donate after death. But again, there's still not enough kidneys out there. So in New York City, the wait time is about 8 to 10 years 8. To 10. Years or donated kidney. Yeah. Wow. Of being on dialysis for most of that time. In other states, it's a little faster.

47:10 In fact. Actually, it's going to sound very morbid. But in states that they don't have motorcycle helmet laws, the wait times for kids for organs are as much shorter. Really. Yeah. Because they have so much brain death from motorcycle crashes. The motorcycle? Wow. They're. Known as Donor Cycles in the Community. It's a double depressing subject now. I heard in the news a few weeks ago. Actually it was at NYU. They've now been able to genetically modify a kidney and actually have a pig grow a human kidney internally or almost human kidney, and then potentially use that to transplant to a human.

47:55 That would be incredible because you bypassed a whole rejection problem. How far along are we with that and when do you think that will be reality so that people don't have to wait 8 to 10 years? So yes, NYU is doing a lot of work on this. I actually have a have a friend, a former student, who got to participate in some of those surgeries. So she's told me about them. But the idea is that, you know, if we could grow kidneys in pigs, we'd be fine, right? We could just grow a lot of pigs on a pig farm.

48:26 But the human body not just rejects other organs from other humans, they recognize it has a different genetic code. They they recognize that it's foreign. And what is, you know, our our bodies fight for and things that usually keeps us alive. They can recognize in a pig that it's a different species. And so the minute you would put that kidney in a human or heart in a human, right, I think they're drinking pig hearts as well. The body would just immediately start fighting it. They were able to figure out some of those genetic markers and and change them.

49:00 So they genetically modify these markers so that the body doesn't recognize it as foreign as quickly. And so they've been doing these surgeries and so sometimes they've done them. And I can't remember which center did what. One center, I think it was Hopkins or University of Maryland and NYU was the other, you know, did it in a a patient who was already brain dead. So the idea is that if it doesn't work, you're not really harming the patient, right. So you can see how long it works for. And I think after a certain period of time, they removed it and looked it under under the microscope to see if there's evidence of immune cells, human immune cells fighting this organ.

49:38 And I think they did see some, but it lasted substantially longer than a non genetically modified organ would have. And humans, they've also done it in patients. I believe there's a heart transplant patient who was determined by the heart transplant center to not be a candidate for a donor heart. And and there was debate about the ethics of this, but they gave him this this pig heart to see how long it would last in a human. And I think it did last longer than they expected, but it didn't last forever.

50:12 I think the ethics of that in a in kidneys is is is different because in kidneys we do have dialysis. So you're not going to you know first unit of harm and so giving an organ that we're not sure it's going to work when we have this other modality that's not perfect but pretty good creates a bit of an ethical quandary. But I do think they they put it in a maybe in a brain dead human. Same idea that you could see at least if it works maybe it's maybe it'll work. It'll be amazing if it does. I. Think probably within five years we may figure out how to grow that in in pigs and also prevent rejections or or reduce the risk of that.

50:53 What's the success rate of kidney transplants? So that is going to vary and it's going to vary on a few things. The best transplant you can get is from a living donor. And and there's a lot of reasons for that. But one is we generally only take kidneys from healthy living donors. Because if you're going to take a kidney out of someone, you want to make sure they don't have diabetes, They don't have kidney disease, and in fact, it turns out patients who donate kidneys. So a plug for donation if you donate a kidney as a living donor, you live longer than a person who doesn't.

51:25 Now you may say that doesn't make any sense, but it's the same reason astronauts live longer than the general population. It's not that space makes you more fit, it's the people we choose to go to space tend to be healthier. Same idea. You've checked out the donor with all sorts of testing and imaging. So they tend to be healthier. But you also have a very short amount of time between the time the kidney is taken out of the donor and put into the recipient. It's generally in the OR next door. So what is it?

51:57 10 minutes maybe. And so kid, you know, organs without blood supply become damaged. So the quintessential organ without a blood supply is you actually take the organ out of the body. So for a patient who is has a deceased donor, you may have heard stories, right, you fly the kidney up or the heart up from Georgia. So that whole plane time, it's called ischemic time where the it's not getting, I mean they have these like special solutions that preserve it, but overall it's not getting oxygen and cells are dying.

52:33 So those kidneys don't work as well as the living donor kidneys do. And and we've had to make a trade off actually, you know we have a shortage. We have 8 to 10 years wait and we know that patients who have kidney transplants live longer than patients who are on dialysis. So then you have to start making choices. Are you going to be willing to take a less good kidney and not perfect kidney? Right. And then recognizing it may not last that long, but at least you can come off dialysis. And so those are some of the things that we ask our patients about generally we we don't offer that to let's say to a 20 year old cuz we want that kidney to last 2025 years, right.

53:15 But if you're 60 or 70 maybe you don't need a kidney that last 2025 years and you can be willing to take it's called expanded donor criteria. So you may take a kidney from someone who had a little hypertension, you know, a little, a little diabete, because it's a compromise. It's a compromise, absolutely. And so the people who give up one of their kidneys do quite well with just one kidney. Yeah. I mean, I think it really shows you how much reserve you have in your kidneys that you can lose an entire kidney and be completely fine, completely normal numbers actually after you lose that kidney.

53:50 Right. So that's pretty amazing that they would that was built in by God or evolution or both. And and I will tell you this, if you're thinking about donating, if you donate a kidney and for whatever reason the remaining kidney fails, you actually jump to the top of the line for the next kidney. Really. Yeah, they reward you. So tell the audience that's listening how they can donate. How they can donate. Yeah, talk to your talk to your families. You can sign that organ donation card, but ultimately your families can overturn it if they want.

54:24 That's in New York. That's in New York. There's no system here in the US it's been discussed about an opt out system. Right now it's an opt in system. We would have a lot more organs if we had an opt out, meaning everyone is assumed to be a donor unless you say otherwise. But talk to your families, it is. It is an incredible gift because if you donate kidneys, many of those patients are not or people are not just donating kidneys. They may also donate a liver and a heart and lungs and a cornea and right other other organs and make dramatic improvements in people's lives.

55:01 We have a a small bowel pancreas program at Sinai and you can you can get small bowel and pancreas transplants as well. You mentioned earlier when we spoke Mount Sinai has a huge nephrology or or kidney department. Can you tell us a little bit about? That so we have a tremendous kidney department. I actually don't know the total number. It's probably about 40 of us. 40 kidney doctors. 40 kidney doctors. And that's because many, you know, just like I have this role in medical education, many of my colleagues have other roles.

55:32 So maybe they're 25% clinical, right. So they only see patients 25% of the time and the remaining 75% of the time they're doing research. So they're doing what we call basic science research, meaning they're working at a bench with cells, you know and microscopes, some like this like this woman, right. Some of them may be doing clinical research. So a new drug comes out and they're recruiting patients for this drug to see if it's working or not working. And now they're doing a lot more of of genetic AI research.

56:04 So the idea is that you take, you know, you they're they're doing a project, I believe they're trying to get a million people who are in the hospital system to share their DNA with the hospital system. It's all anonymous. But once I have, you know, we call them patient 12 and I have their DNA and I have their whole medical chart so I can see what diseases they get. Then you can, this is where AI machine learning has is becoming huge. You crunch all those numbers, or the computer crunches all those numbers for you and they can make predictions.

56:40 So they can say if you have XY and Z, you are much more likely to need to go to an ICU on the submission. So keep an eye on that patient because they're much more likely to go to an ICU, So predictive. Right. Or they may be able to crunch this data and say this gene we think may have a role in this disease, that's what she's, that's what she's doing, she's. Got the computer. She's got this alien kidney, yeah. Future kidney. That's pretty amazing. So for the average person, at what age should they be checking their kidneys by having these blood tests or or seeing a doctor?

57:18 If they have no symptoms, no problems. I think in general seeing a doctor once a year is, if you're a healthy person is a good idea, right? We can catch a lot of the diseases that are silent. Blood pressure is a a particularly good one. You can have completely normal blood pressure most of your life and something about turning 40 turns those genes on and you can develop hypertension. So you know, basic screening tests can be done yearly for anybody. And and generally that's not urine, that's just blood for certain populations of people who we know are at higher risk, like people with diabetes, people with hypertension, people with family histories, some diseases like people with lupus, It's more important that we check your kidneys out because just because we know you're higher risk.

58:04 And so those patients are generally recommended like twice a year to do urinalysis to look for protein. And another population of patients who we screen are patients who are pregnant, right, Because these, these are usually healthy people and having a kidney problem or a blood pressure problem is going to be devastating. So if you've ever been pregnant, you know that every time you go for a prenatal visit, you are asked to pee in a cup. And what they're looking for is high sugar to see if you're developing diabetes and they're looking for protein to see if there's a problem with your kidneys during the pregnancy.

58:40 So it's pretty easy to check the kidneys out and then make sure you're healthy with non invasive. Testing and not imaging I I just want to make you know right. We don't usually do imaging to diagnose kidney problems. So if you you know someone will say I think you need to check my kidney, it's hurting that's probably your lower back. The kidneys don't really cause any pain unless you have a kidney stone, then it's intense pain. But we don't check. We don't usually use imaging, and certainly not as a screening test.

59:09 Right. So it's it's safe and easy to do. Well, this has been a very fascinating and highly educational discussion. I I learned a lot and I'm sure the audience has learned a lot as well. I'd like to thank you again. Thank you for coming today. It's a pleasure. It's a pleasure to have me and, you know, take care of your kidneys. I would say you only have one, but you actually have two. But they generally go down together, so it's important to protect both of them. All right. That's great. Great advice.

59:35 Thank you very much.