The Impact of Nutrition, Diet and Lifestyle on Solitary Kidney Function - Kamyar Kalantar-Zadeh

May 8, 2020

Jamie Landman and Monty Pal are joined by a multidisciplinary panel of experts to discuss the correlation between diet, nutrition, and lifestyle on solitary kidney function and cardiovascular health.


Kamyar Kalantar-Zadeh, MD, MPH, Ph.D., Chief and Professor, Department of Medicine’s Division of Nephrology & Hypertension, UC Irvine

Connie Rhee, MD, Assistant Professor, Division of Nephrology, Department of Medicine, UC Irvine

Michael Staehler, MD, Ph.D., Professor, Department of Urology, Head of the Interdisciplinary Centre for Renal Tumors, Ludwig-Maximilians University, Munich, Germany

Dena Battle, Co-founder, and President for KCCure a passionate kidney cancer patient advocate. She began her career in Washington, DC, as a congressional aide, and went on to work as a lobbyist for more than 10 years, working primarily on tax and healthcare policy. She serves on the Advisory Board for the Johns Hopkins Sidney Kimmel Cancer Center and as a member of the Patient and Family Advisory Council. She has testified before the FDA – Oncological Drug Advisory Board (ODAC) and helped co-author an NCI-ASCO-sponsored paper on improving end-of-life care for cancer patients. In 2009, at the age of 40, Dena’s late husband Chris was diagnosed with metastatic kidney cancer. Together, they began a quest for the best care possible to combat the disease. Chris was treated at four different comprehensive cancer centers and participated in multiple clinical trials.

Jaime Landman, MD, Professor and Chairman, UCI Department of Urology, UC Irvine Medical Center

Sumanta Kumar Pal, MD, Associate Professor, Department of Medical Oncology and Therapeutics Research, Co-Director, Kidney Cancer Program, City of Hope

Read the Full Video Transcript

Jamie Landman: Welcome to Kidney Cancer Today. I'm Jamie Landman, Chair of the Department of Urology at UC Irvine, and here with my wonderful partner, Monty Pal.

Monty Pal: Jamie, how are you this morning? Monty Pal, medical oncologist at the City of Hope Cancer Center here in Los Angeles.

Jamie Landman: We have put together an amazing panel of experts today to discuss what is what I think one of the most important and underappreciated topics in kidney cancer, which is kidney function.

So over a decade ago, I remember one of my partners at Columbia University, Jim McKiernan, bringing an article to my attention from Alan Go and he had over a million patients out of the Kaiser system, and they showed that kidney function correlated absolutely and directly with cardiovascular health, the biggest killer in the United States and around the world in many of the first world nations.

So what basically I realized at that point is that when we diminish a patient's kidney function beyond what they need for the cure of their cancer, it is, in an unvarnished way, a form of unintentional manslaughter because we're shortening their life on the far end. Now that's highly debatable because of acute kidney injury from surgery versus kidney injury for medical reasons, but still, something that I think is an important topic that's underappreciated.

And I'd like to start by introducing our crew. We have Ms. Dena Battle, who's head of KCCure, a patient advocacy group out of Washington DC that's really been a champion of patients with kidney cancer. We have Dr. Michael Staehler who's Professor and the founder and Chief from the International Center for Kidney Tumors in Munich. And then we have out of UC Irvine, an amazing team of nephrologists, Dr. Kam Kalantar-Zadeh, who's Professor of Medicine, Chief of the Division of Nephrology, world-class nephrologist, as well as Dr. Connie Rhee, Assistant Professor of Medicine and Assistant Professor in the School of Public Health, who is an NIH-sponsored scientist, having won many awards for her work in endocrine derangements in chronic kidney disease.

And I'd love to start off with you Dena, can you help us understand the patient perspective on this really important topic?

Dena Battle: Absolutely. And thanks to you guys and to UroToday for hosting this and bringing the patient perspective into light. Seventy-five percent of patients as you know, are diagnosed with localized disease. A lot of these patients have small renal masses, and regardless of whether someone has a small renal mass or a large renal mass, we know from our data that they have the same level of anxiety. They are really frightened and worried.

And often their first instinct is, "I've got to get this out of my body and I want my whole kidney gone. I think that will have a safer oncological outcome." They're reluctant to get second opinions. They don't feel like they have time to do that. And one of the things that we encourage as patients are diagnosed is we remind them that they actually have time to stop, that they can seek out a second opinion, and to let them know that partial nephrectomy is just as safe oncologically as a radical nephrectomy. But that preserving that kidney function is really an important thing. So it's really helpful to have experts like you guys weighing in to share this with patients and provide that level of reassurance.

Monty Pal: Well Dena, I think we're equally lucky to have advocates like you in the kidney cancer community to bring these issues forth. Michael, what can we do to address this? Any surgical strategies in your mind?

Michael Staehler: Well, one of the biggest problems is the overutilization of nephrectomies. It's so simple to take out the kidney and if you do that with a laparoscopic or robotic approach, it's really fast and you don't have a lot of complications, especially in small tumors. Patients going home fast, you don't have a lot of trouble with that.

And then you can figure out what's going on and you can tell them, "Hey, I saved your life because I took out the cancer." You don't tell them that you took out some of their body functions as well, which they might want to keep actually. And they are so happy to get rid of the cancer that they're not thinking about the longterm effects of what's going on there.

I think we need to train people more how to do partial nephrectomies. We have to have classes for surgeons and we have to have a little bit of an incentive in doing partial nephrectomies over nephrectomies and that's going to be something we can work on. Just at our center, when I started there 15 years ago, we started with 10% of partial nephrectomies. We're now at 45% and we see a lot of patients with really big tumors where you definitely can do a partial.

And I think we have to save those nephrons, we have to preserve their renal function. The next thing after the surgery, which is going to happen, is that the radiologists are not going to be able to administer contrast because they say, "Hey, you only have one kidney and it's not safe to administer contrast," so they don't get an adequate staging after that. And as you already said in your introduction, we're giving away some of their lifetime and we really can prevent that. It might be a little bit more complicated for us as surgeons, but we should be dedicated to the patient enough to go through that hassle.

Jamie Landman: Well, this is a great introduction and what we have here is a possible solution, because not only do we as surgeons need to focus on important nephron-sparing approaches, but we have to protect people's kidneys thereafter. At UC Irvine, we started the kidney health program for all patients who undergo kidney surgery that we started about a decade ago in conjunction with our nephrology team. So I'm going to pass it off to Dr. Kam Kalantar-Zadeh and Dr. Connie Rhee to update what we can do to protect our patients' kidneys after sparing as many nephrons as possible, in the longer term.

Kamyar Kalantar-Zadeh: Yes, thank you, Jamie. It's such a great pleasure and honor to be part of this important program. As a nephrologist, that means as a different type of kidney doctor, I usually am responsible for the education of patients, family members, care partners, pertaining to what it means having less than two kidneys. And these are usually not only patients coming from you, but also patients who have donated a kidney. You see, it's quite interesting to know that majority of people who have one kidney are actually those who donated one of their two kidneys to somebody who needed kidney transplantation, right?

So that's the good news. I usually start with this analogy, I say that, "Now you have come to me, one of your kidneys was removed or one and a half out of two portions of your kidneys are gone, and now you have one or less than even one portion of the kidneys left. But first of all, there are many more people who have one kidney and until recently, we used to say that if you give one of your two kidneys to somebody else, you don't need to do anything. Now, that wasn't quite correct. Studies have shown that there are actually certain implications and conditions that could have some impact on the outcome of kidney health. Now, what we are saying nowadays, that if you have less than two kidneys, you need to cherish what is left. You can't just go and take it for granted that "one kidney is all I need". Actually, let's make sure that one kidney lasts another 50 years or 100 years. So I start with that.

And then I go over the physiology and something that's quite understandable for patients at different educational background levels, and I tell them that it's similar to a fish tank with two filters. Now one of the filters or pumps is gone, there is only one left and the entire fish tank is now dependent on one, instead of two. So we need to make sure that that one stays ongoing, good working, for the next 10, 20, 30, 40, or 50 years. And with that comes the role of lifestyle, nutrition, diet, and we usually summarize this in three things.

Number one, please avoid too much protein intake. Why? Because protein intake, too much protein, and I'm not against eating adequately and enough, what I'm telling them is that if you're one of those who is taking a lot of protein or especially the animal-based protein, some data suggests that could cause overburden on your kidneys, even if you have two kidneys, right? Not to mention, now you have one kidney, so please be careful. Please try to adjust the lifestyle towards less than excessive amounts of protein. We usually say avoid protein intake more than one gram per kilogram body weight per day, which is more than enough actually. And try to have a more diversified source of proteins, for example, more plant-based protein, than being excessively animal-based protein. Because plant-based protein, data suggests that they're more kidney-friendly and more protective of kidney function.

Number two, please avoid obesity. Make sure that you are not going above the obesity level, which is body mass index of 30, especially not above 35 kilograms per meter squared. So 35, ideally body mass index below 30 for most Caucasians, and for Asians even lower, based on what is their adjusting for race, ethnicity, background.

And the third one is to please be careful with controlling high blood pressure. If you or any family members have high blood pressure in the background or you, yourself, we need to make sure that blood pressure is well controlled. And the last one is essential other comorbid conditions such as diabetes and other things. So in summary, it's important, if you have only one kidney left, or less than one kidney or less than two kidneys left, to ensure that kidney health is properly provided through lifestyle modification and adjustment as discussed. Thank you.

Monty Pal: Thank you, Kam.

Jamie Landman: So thanks, Kam. That was incredibly helpful. Connie, I'm going to ask you a quick question. I personally have changed my lifestyle tremendously, and a lot of what Kam said was about overall health, cardiovascular health, weight, and have switched most of my protein to a plant-based source, so whole food, plant-based diet. Do you think that kind of an approach, not only limiting your protein but limiting your animal protein might be important?

Connie Rhee: Yeah, absolutely. Yeah. I think I have really great admiration of this kidney health program that you and Dr. Kalante\ar have cultivated at UCI. And I think it's provided a lot of resources for these patients who now have partial nephrectomies or total nephrectomy.

Actually, I think one of the main take-home points that I think the dietitians who are trained in kidney nutrition, that are [inaudible] our patients for an important partner in our management. So I think, although a lot of research is still needed, I think there are a lot of salutary effects of plant-based proteins and with animal-based proteins, particularly for cardiovascular health, I think, which is an important complication of chronic kidney disease, and we actually see a better impact in terms of patients' electrolyte and bone disease balance.

For example, animal proteins have greater absorption of phosphorus. So we have better control of phosphorous when patients are having plant-based proteins as opposed to animal-based proteins. So I think with respect to impact on also acid-base disorders, there have actually been some really interesting editorials I've written. Instead of patients taking a bicarbonate pill, if they have more produce in their diet like fruits and vegetables, this can actually replace that. So in terms of better acid-base response because as we know patients have more protein intake, they have more acidemia as well. So I think there are just multifaceted potential benefits of an animal as opposed to plant-based protein.

Just one caveat that we have to watch for. But the good thing is there are pharmacotherapies that can address this is, all the healthy fruits and vegetables that patients eat may have a lot of potassium in it, and in some patients with impaired kidney function, we may see hyperkalemia. But the great news is that we now have pharmacotherapeutic [inaudible] they should see it administered under the care of a nephrologist or urologist or primary care doctor that can help manage this so patients can, in fact, eat these really healthy potassium-rich plant-based diets without having this called hyperkalemia that can affect their heart

Jamie Landman: So much, guys. That was very helpful. I'm going to just ask, Michael and I have the privilege of curing people's cancer by cutting out cancer with pieces of the kidney. Monty has the privilege of managing patients with devastating disease who often have one kidney because they've lost one of their kidneys or more to surgical intervention. So after the three of us deal with this, and try and save the kidneys, but lose it. Should there be a protocol or can you suggest a protocol? Does everyone need to see a nephrologist? Is there a standardized diet? Is there any basic information that patients should have? What do you think we should suggest as [inaudible].

Kamyar Kalantar-Zadeh: Well, maybe I start. So first that in my opinion, everybody who has one kidney or kidneys removed need to see a nephrologist for the same reasons that you astutely alluded to that, and not to mention as the most important part is the education. That's very important. That means to educate the patient, to reassure the patient that life will go on, but with certain adjustments. So that's my two cents here.

Michael Staehler: So Jamie, I want to applaud you for your project actually. This is really the right thing to send to every patient after any kind of kidney surgery that takes away some of their renal tissue to a nephrologist. Can I ask something from my side to the nephrologist, what I learned is that in the longterm creatinine might not really be the best way of estimating the function of the kidneys and that after five to 10 years latest, a patient really needs a nephrologist to explain and understand his renal function.

Kamyar Kalantar-Zadeh: Yes. This is again Kam Kalantar from Nephrology Division at the University of California Irvine and the answer is that yes, the nephrologists and nephrology educational team should play a very crucial role here to educate the patient and also not only just the patient but patient's family members, patient caregivers, now there we say care partners, and also the health care providers including primary care doctors and other colleagues, surgeons that here we are like a team together to ensure that what is left of his kidneys keeps working, right?

Now, I think one thing I forgot to mention that not infrequently, some of these patients who required nephrectomy, one of his kidneys should be removed, they already have preexisting conditions, right? Nowadays we are living in a society where diabetes on the rise, obesity, hypertension, and most people who need dialysis, they already have two kidneys and yet the two kidneys failed. Not to mention to have now one kidney, so therefore we need to understand one of the reasons that Dr. Jamie Landman said they sent patients to us even before surgery, before removing the kidneys, to assess what is there and to calculate and estimate what will happen after that.

For example, if the kidney function is already down to 50% or 40% before removing one of the two kidneys, then we tell the patients after removing one of the kidneys because kidney cancer, it's going to go down from 50% down to 30% and we need to count on these things. We need to have projections when kidney function continues to get worse and more reasons for us to work together. But this is teamwork. This requires a lot of education and also a lot of ongoing research and collaborations that we are doing here.

Jamie Landman: So another remarkable bit of information for Kidney Cancer Today, I'm going to close this with what is going to sound like a very odd statement. Everyone who's on the line today knows how devastating kidney cancer is. I have, as I'm sure everyone on this line has lost your friends and patients to kidney cancer. And yet I will say this is a bright spot. Thanks to Doctors Rhee and Kalantar, and to lifestyle changes, I can honestly say one of the most unusual things I've ever heard is that the patients with localized disease who we cure and introduce to this kidney health program will often adopt a healthier lifestyle with everything that the team talked about, meaning little weight loss, little cardiovascular health and dietary changes, and often that is a plant-based whole food diet and many patients, it's not a couple, and I was shocked decades ago when I first heard this and now I'm less shocked, tell me that kidney cancer was the best thing that ever happened to them.

That's not diminishing the fact that many people die and we've all lost to this disease. But you have to look for that silver lining on this very ugly cloud, it's that if you are cured of your disease, you can take the opportunity to protect the rest of your kidney and improve your health with important dietary and lifestyle changes. So with that, I want to thank our guests, our two regulars now, Dr. Michael Staehler and Ms. Dena Battle, who always provide amazing insights, and in this case, Doctors Connie Rhee, Doctors Kam Kalantar-Zadeh are world-class nephrologist and kidney experts, and of course what I always say is my better half when it comes to kidney cancer, Dr. Monty Pal. Thank you for some wonderful information.

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