“So again, especially early in the pandemic, we saw very high rates of severe acute kidney injury in patients in the ICU with uh, COVID and in some studies, this was as high as 30, 35% of patients developing acute kidney injury, many of whom needed dialysis.”
In this episode, Dr. Heung talks about his research focus in acute kidney injury (AKI), the effects of COVID-19 on the population of dialysis patients, and how we can keep our kidneys healthy.
Dr. Heung is a nephrologist (kidney specialist) at the University of Michigan where he has practiced since 2005. While he is a general nephrologist and sees patients with a wide variety of kidney diseases, his particular research focus area is acute kidney injury.
Shireen: Dr. Heung talks to us about his research focus in acute kidney injury, the effects of COVID-19 on dialysis patients and how we can keep our kidneys healthy.
Podcasting from Dallas, Texas, I am Shireen. And this is the Yumlish podcast.
Yumlish is working to empower you to take charge of your health through diet and exercise and reduce the risk of chronic conditions like type two diabetes and heart disease. We hope to share a unique perspective and a culturally relevant approach to managing these chronic conditions with you each week.
Dr. Heung is a nephrologist at the University of Michigan, where he has practiced since 2005. While he's a general nephrologist and sees patients with a wide variety of kidney diseases, his particular research focus has been on acute kidney injury.
Welcome Dr. Heung.
Micheal: Thank you. Thanks for having me.
Shireen: An absolute pleasure.
So, Dr. Heung, can you talk a little bit about how you gravitated toward your specialty in nephrology and just your career journey to becoming Clinical Chief of Nephrology at the University of Michigan?
Micheal: Sure. I've always really had a strong affinity for the kidneys. They're just a very cool organ. The more you know about them.
Unfortunately, most people don't know a lot about the kidneys, but they really play a critical role in the body. Their main function, mostly people think about is to make urine and get rid of waste. Um, and that is a key function. If we're really focusing on what the kidneys overall role in the body is, it's really to maintain balance or homeostasis for the body.
And that balance is in the form of waste products, in the form of blood pressure, in the form of fluid chemistries acid-base, so really a lot of roles that intersect with a lot of different systems, all the different systems in the body, really. So, I've always been fascinated by the kidneys. I had great role models and mentors along the way that guided me into this specialty and continued to guide me, of course, as, as I continue to grow.
And I was very fortunate to be able to come and do my fellowship at the University of Michigan. I very much enjoyed my time here. Go blue! And when it came time to choose a career, I just couldn't think of any better place to, to continue my career than to work at the University of Michigan. Having been here for a number of years now, I really feel like I've grown up in that program.
And, uh, along the way, I've, I've, uh, become promoted to, uh, serving as the Clinical Chief of Nephrology. And it's really a great honor to be able to give back to the place that trained me and gave me my first opportunities. So, uh, I very much, uh, have enjoyed the journey so far.
Shireen: And so, your main area of research is acute kidney injury? What is the definition of acute kidney injury and what are the risk factors for this condition?
Micheal: So acute kidney injury is an abrupt decline in kidney function. This can be quite dramatic. It can be complete kidney shutdown and by abrupt, I mean, on the order of potentially hours to days, uh, as opposed to chronic kidney disease, which is more common, but tends to develop over months to years.
Another key difference is that acute kidney injury often can be reversible. Whereas when we talk about chronic kidney disease, we often by definition think of that as irreversible. So acute kidney injury, most commonly occurs among hospitalized patients that are sick, especially those in the intensive care unit that are critically ill.
So, any major acute illness, such as a severe infection is a major risk factor for acute kidney injury. Having any predisposing, pre, pre-existing chronic kidney disease or kidney impairment is another major risk factor for kidney disease. And actually, unfortunately there's a lot of things out there that are also potentially risk factors because of their toxicity to the kidneys.
And this includes prescribed medicines, but it also includes over the counter medicines and one of the very common ones that is probably in all of our medicine cabinets are INSEAD's, which are the nonsteroidal anti-inflammatory drugs. Examples of that would be ibuprofen, which is the same as Motrin or Advil or Aleve, which is the same as Naproxen or Naproxen.
So, again, these are very common medicines throughout our medicine cabinets, but unfortunately taken in high dose or for longer periods can, can hurt the kidneys and lead to acute kidney injury, which can then in fact, contribute to chronic kidney disease as well.
Shireen: And so, what I'm hearing from you is that, uh, the acute kidney injury can be traced back to prolonged and high doses use of some of these medications that are available.
Micheal: Yes, unfortunately.
Shireen: Um, what are some current available treatments and what is the direction of research who were new and better treatments or prevention of acute kidney injury?
Micheal: Well, I really liked that you asked about prevention because, uh, that's really where I think the focus should be the reason for that is because unfortunately our treatments are, are pretty inadequate at present.
Basically, when the kidneys suffer a significant injury, we are left with trying to support the body, support the work of the kidneys to the best of our ability in extreme cases, such as in the intensive care unit where I get to work a lot. When the kidneys shut down in a situation such as severe infection, such as for example, a severe COVID infection, which unfortunately we've seen a lot of in the past couple of years.
In those scenarios. Basically, we have dialysis to offer and many times the families believe, or patients think that dialysis is going to help kickstart the kidneys and support the kidneys. But in fact, dialysis does not do anything to help restore the kidney function. It's really to help do some of the function of the kidneys.
We balance some of the waste products, the chemistries and things like that for the kidneys. And really it is biding time. Dialysis is a form of life support until the body can hopefully heal itself. The kidneys can heal itself and resume that function and patients can come off dialysis, which can absolutely happen.
But as you can see, it's, it's mainly supportive care in the form of dialysis. There are no medicines that are really established to help reverse kidney injury. But we also do know that many cases of kidney injury can be preventable, or they can if caught early on, can be prevented from getting worse at least, and having worse complications.
So, in terms of directions of research, there's still a lot of research looking at better therapies for acute kidney injury, of course, but in terms of. Prevention. Some of the exciting work that I think is being done and I have the opportunity to be involved in some of this work is looking at, for example, artificial intelligence approaches to predict who is on their way to developing acute kidney injury so that we can, intervene ahead of time and actually prevent them from getting there or prevent them from progressing along that pathway. Uh, we're not quite there yet. We're not quite at the point where we can prevent a lot of, of AKI, but I think we're learning more and more. And there have been several studies that have shown us proof of principle, that if you apply these in the, in the right way, you can make a dent in the overall impact of acute kidney injury.
So, I really think, continued focus or even more focused on that prevention is really important going forward.
Shireen: I want to come back and touch on dialysis that you mentioned. I do have a follow up question when you mentioned the AI piece, however, what are some predictors that can help map out? And it's, you know, just general predictors. I know these models are way, way more precise, but are there some predictors that can be built into such models? That can help predict out exactly what AKI may look like for someone?
Micheal: Sure. And it comes back to the known risk factors. So, we try to make these models as dynamic as possible. So, in other words, taking into account real-time information and real-time changes.
So, for example, changes in blood pressure, a very significant drop in blood pressure, low blood pressure hypotension could be a sign of sepsis, a severe infection, or it could be a sign of dehydration or could be a sign of over-medication. But regardless of the, cause it can potentially lead to kidney injury.
So being able to see that trend and it can be relative, you can drop to a normal blood pressure, but if you're used to having a very high blood pressure, that could also be a relative drop in blood flow to the kidneys. Identifying these patterns, and that's why we need the artificial intelligence, the really strong computers to help us tease out these patterns that may not be quite as obvious to the naked eye sometimes.
And of course, the combination of factors, so maybe a modest drop in blood pressure, but they also got a medicine that can be toxic to the kidneys and maybe some other factor coming along the way. So, we look at a number of factors. What are some of the patient comorbidities that are predisposing, including the preexisting kidney disease?
What are the medicines, you know, potential risk there? What are the vital signs doing? What are, what procedures or tests are getting ordered? And with a combination of all that information, trying to tease out those patterns where it looks like somebody may be at a risk of evolving into acute kidney injury.
Shireen: Interesting. Thank you for sharing. Um, you were quoted Dr. Heung getting a recent ProPublica article about the effects of COVID-19 on dialysis patients discussing the unprecedented mortality tool on dialysis patients. What are some of the reasons for this population's unique vulnerabilities?
Micheal: Yeah. Unfortunately, we really saw a lot of poor outcomes during this pandemic. And whereas over the last couple of decades, we've really seen some improvement in survival, on dialysis for patients, uh, which I think is a really great testament to, to the field moving forward in the last couple of years, that curve unfortunately changed.
And it's almost certainly due to the impact of the COVID pandemic and the reason these patients are so vulnerable is because quite simply dialysis is not an elective procedure. So early on in the pandemic, when, you know, a lot of people were getting switched to virtual health care, or many of us were just bunkering down, you know, school's closed work from home and everything and not, not go out and expose well dialysis patients, uh, for the most part do not have that option.
This is a life prolonging therapy. You cannot stop and skip dialysis for two years of, of the pandemic before getting back together in the dialysis unit. And so having to go to the dialysis unit and the potential exposures there. Dialysis patients of course have chronic illness, the kidney failure itself, and then potentially the other conditions that might have contributed to the kidney failure, like diabetes, high blood pressure, cardiovascular disease.
So, all of those things could also predispose to worse outcomes related to the COVID pandemic. And another factor is that dialysis units are wonderful places in terms of efficiency and providing very good care for dialysis patients and delivering this life sustaining therapy. But a dialysis unit is actually an open room, so it's not a completely private facility, it's a private facility. It's not a completely private station. You're seated, you know, several feet away, but you're seated adjacent to people, and they also see units where we're never developed to be perfect places for, uh, airborne precautions. There's basically no built-in airborne barriers between places.
And so. They're well-developed to control spread of bloodborne illness. And we have a lot of protocols around that because of the blood movement, obviously, but in terms of airborne illness, a lot of work had to be done to adapt to dialysis units. And I think a lot of credit needs to go to the field and industry as well for working together.
I think there were very admirable efforts to provide care for dialysis patients, or it could have been even worse. To be honest.
Shireen: Can you expand a little bit on that interaction between AKI and COVID-19 and what that has looked like?
Micheal: Sure. Unfortunately, because especially early on in the pandemic, many patients, got very severely ill with COVID-19.
They developed pneumonia, they developed a, what we call acute respiratory distress syndrome, where basically, uh, lungs are filled with fluid and inflammatory cells and unable to really have good oxygen exchange. With complications from COVID-19 people with developed sepsis and septic shock, and those are major reasons for the development of acute kidney injury.
So again, especially early in the pandemic, we saw very high rates of severe acute kidney injury in patients in the ICU with uh, COVID and in some studies, this was as high as 30, 35% of patients developing acute kidney injury, many of whom needed dialysis. So, it, it really was an epidemic within an epidemic, uh, within a pandemic of acute kidney injury, whether that is a specific syndrome to COVID-19 or not is still a little bit unclear.
We know that COVID-19 can go to the kidneys. It can cause certain syndromes in the kidney. But the most common syndrome that we saw was probably a more non-specific syndrome, um, which is simply acute kidney injury from critical illness and shock, uh, which could be from COVID-19, but could be from the flu, could have been from other bacterial illnesses as well.
So, I think that's the most likely reason there was so much acute kidney injury, just because there was so much severe illness in COVID, but we are still learning more about that.
Shireen: So, coming back to prevention that we talked about, or, you know, a few minutes ago, what can one do to keep their kidneys?
Micheal: Well, again, the kidneys play a really central role in the body and it's all about balancing.
And so, anything you can do to keep your body healthy is going to be good for the kidneys and help your kidneys stay healthy. Some specific examples that I talk to my patients a lot about include blood pressure. High blood pressure is an extremely common condition. It increases with age. Um, most Americans will develop high blood pressure during their lifetime and high blood pressure can, uh, absolutely contribute to kidney dysfunction or worsening of chronic kidney disease.
Not to mention, of course, uh, being, uh, a risk factor for cardiovascular disease and stroke and other complications. So, maintaining a good, healthy lifestyle, watching the salt or sodium in your diet, of course, getting regular checkups to monitor your blood pressure, taking medicines, if prescribed to control the blood pressure.
All those are important factors. Diabetes, diabetes is the leading cause of kidney failure in this country. And I know a very important topic for you in this podcast. And I think there's a lot of improvement we can still do for many people with diabetes, going back to again, lifestyle interventions, to eat better, to watch, um, carbohydrates, watch the sodium as it relates to the blood pressure as well.
We know that better control of diabetes can reduce the risk of kidney disease or reduce the risk of progression of kidney disease in patients with diabetes. So, when you think about it, like what I just talked about, hypertension and diabetes are two of the leading causes of kidney failure. And yet they're both treatable.
They're both, it's not easy necessarily, but they're both treatable. And so. I think those are one in one A, when we talk about focus and maybe one C right up there is his weight is controlling our weight in part, because it really feeds into those other two factors. So, controlling the weight or being able to lose some weight, if you're overweight or obese, often leads to better glucose control. If you do have diabetes, certainly can lead to better blood pressure control. If you have hypertension and overall, those factors will lead to better kidney health and a lower risk of significant kidney disease.
Shireen: And it seems like lifestyle, all biases included, but it seems like lifestyle in itself has such a huge impact across these disease days, right?
To be an overweight obesity, diabetes, and kidney failure that can come as a result, hypertension, cardiovascular disease. It feels like the common thread across all of this is that lifestyle change is being able to make some of those modifications. And of course, there's quite a bit of work that, you know, there are other external factors at play as well, certainly, but it seems like these, across most of our episodes, we've seen, these are common themes that keep coming up again and again, is, is that life cell?
Micheal: Absolutely. And again, I spend actually a lot of time in clinic when I'm seeing patients talking about weight, weight control, weight loss. I, I wouldn't say I'm a specialist in that I'm not a weight loss specialist by any means, but I, I believe in it so much because again, gonna make it so much easier to control your blood pressure, your glucose.
Um, for diabetes and therefore, uh, reduced your risk of significant kidney disease. And I'm not, I never tell people it's easy cause I, it's not, it's not, I've tried to lose weight. It's not easy, but you have to find ways that are sustainable. And honestly, as a physician, uh, as a provider, there's this therapeutic, you know, momentum a lot of times where it's honestly, it's so much easier to prescribe a pill, then make the time to talk about these other factors.
And there are great medicines now that can help with controlling, not just blood pressure, but diabetes. It's actually a very exciting time in nephrology because just in the last several years, there have been newer medicines that have been developed that really seem to have the potential to make a dent in, in kidney disease, more so than from the previous two decades, to be honest, so pretty exciting time.
But it's also important. I think that we don't lose sight of the basics. You know, the lifestyle changes and all these meds, any med is going to work better when it's going to be synergistic with your lifestyle changes.
Shireen: I love that you mentioned that part because it's very easy to say I'm going to just pop a pill for that, but it really has to go hand in hand with, uh, with less intervention.
I appreciate that, uh, with that, Dr. Heung toward the end of the episode, how can our listeners connect with you and learn more about work.
Micheal: Well, I try to stay somewhat active on Twitter. My Twitter handle is @keepingitreno and, uh, that pretty much tells you a lot about me as well. I really love the kidneys as we talked about and always happy to share more about proper habits for good kidney health.
Shireen: I appreciate that. Thank you so much for your time, Dr. Heung, it has been an absolute pleasure having you.
Micheal: Thank you so much.
Shireen: And to our listeners out there, head over to our social media on Facebook, on Instagram, after this episode and let us know what is something you want to do or have been doing to improve your kidney health, either for yourself or a loved one.
Again, head over to our Facebook @Yumlish or Instagram @Yumlish_ and let us know what is something you want to do or have been doing to improve your kidney health. We will see you there after this episode. Once again. Thank you, Dr. Heung.
Micheal: Thank you.
Shireen: Thank you for listening to the Yumlish podcast. Make sure to follow us on social media @Yumlish_ on Instagram and Twitter and @Yumlish on Facebook and LinkedIn for tips about managing your diabetes and other chronic conditions, and to chat and connect with us about your journey and perspective, you can also visit our website at Yumlish.com for more recipes advice, and to get involved with all of the exciting opportunities Yumlish has to offer. If you like this week's show, make sure to subscribe so you can hear more from us every time we post. Thank you again, and we'll see you next time. Remember your health always comes first.