Episode 25: The Impacts of Albumin on CKD Patients with Dr. Kam Kalantar
Low levels of albumin have been associated with increased mortality in patients on dialysis according to many studies. A type of protein made by the liver, albumin keeps fluid from leaking out of blood vessels while nourishing tissues and transporting hormones, vitamins, drugs, and substances like calcium throughout the body. Dr. Kam Kalantar, an expert in kidney diseases and epidemiology, and Professor of Medicine at the University of California-Irvine School of Medicine, joins Field Notes to explain the importance of managing albumin in patients with chronic kidney disease.
Brad Puffer: Welcome everyone to this episode of Field Notes. I’m Brad Puffer on the Medical Office Communications team at Fresenius Medical Care North America, and your host for this discussion today. Here we interview the experts, researchers, physicians, and caregivers who bring experience, compassion, and insight into the work we do every day.
Low levels of albumin have been associated with increased mortality in patients on dialysis, according to many studies. Albumin is a type of protein made by the liver, and it keeps fluid from leaking out of blood vessels, while nourishing tissues and transporting hormones, vitamins, drugs, and substances like calcium throughout the body. So, maintaining healthy levels of albumin is important for patients living with chronic kidney disease.
To help us better understand the importance of managing albumin levels, and to discuss a recent journal publication about this issue, is Dr. Kam Kalantar, an expert in kidney diseases and epidemiology and professor of medicine at the University of California, Irvine School of Medicine. He is also a medical director for a Fresenius Kidney Care Center. Dr. Kalantar, welcome to Field Notes.
Dr. Kam Kalantar: Thank you very much.
Brad Puffer: Well, I provided a very brief explanation of what albumin is and why it's important, but I'm wondering if you can elaborate and from your physician perspective, explain why we should care about albumin.
Dr. Kam Kalantar: Serum albumin is an important protein. It's probably the most abundant protein in our circulations, in our blood. So, serum albumin has a number of important functions. One of them is to maintain the hemodynamic stability within the cardiovascular system, but there are also important other functions, such as maintaining the nutritional status. Also, the molecule is a carrier. That means it carries different other molecules, such as vitamin D and thyroid-related hormones and other things, throughout this circulation or through the bloodstream to other parts of the body. Also, it's a defense mechanism, in that serum albumin is used to remove certain unwanted molecules in the blood.
Therefore, if I wanted to go over so many important functions of circulating albumin, it will go beyond the scope of today's presentation. But suffice to say that whether we are healthy with no disease states or we have disease states, such as chronic kidney disease, serum albumin plays an important role.
Brad Puffer: So, Dr. Kalantar, then how do you go about determining those albumin levels in your patients with kidney disease? Is this something that you measure every day and talking to your patients about routinely?
Dr. Kam Kalantar: Yes. Serum albumin is actually measured every month in essentially all dialysis patients. So, if we have over half a million dialysis patients in the United States, their serum albumin is checked every month, so that should highlight the importance of this measurement. It is measured through highly scenarios method, and it's compared to other patients and compared to the same patient, over time to see if there are any trends going up or going down to see how the patient is doing.
Brad Puffer: Is this something, then, you touch base with your patient about every time you round or discuss with them?
Dr. Kam Kalantar: Yes. Then one of the areas that usually means you measure something, you are now responsible, you have to translate it into the patient’s language. So, I tell my patients, since I'm also a medical director of FKC, a large FKC dialysis center in Southern California, during my weekly rounds when I have this serum albumin of the month available, I always tell the patients that, “Mr. Smith, Miss Jones, this is your serum albumin. It's going to the correct direction, or not quite correct direction.” These are things that we share with essentially all patients.
Brad Puffer: Well, then what are the key causes of low albumin and how do you fix that?
Dr. Kam Kalantar: Yeah, that's actually as you absolutely mentioned, low albumin. Why? Because I would like my patients to have higher serum albumin, and I think I'm not the only nephrologist. We 12,000 nephrologists by providing care to CK and dialysis patients, we would like our patients to be resilient. To do well. Patients should live well with kidney disease, as well as living well, and serum albumin - high serum albumin - is a strong predictor of that.
I would like to make sure the serum albumin is not low, and low serum albumin could happen, usually it's referred to low serum albumin as a marker of nutritional status. That means malnutrition, that is called protein energy wasting, but low serum albumin could also happen due to inflammation, infection and also loss of albumin during the dialysis treatment. If the dialysis treatment, as we’re hopefully going to discuss, how this could happen. So altogether, serum albumin is a very precious protein that needs to be cherished and maintained.
Brad Puffer: And it sounds like nutrition is a big key factor in maintaining high levels of albumin. Is that correct?
Dr. Kam Kalantar: Yes, that's correct. That means that by providing good nutrition, serum albumin is hopefully preserved, or even improved and increased, but this is not the only factor that determines the level of serum albumin in the blood.
Brad Puffer: Well, as we get to those other factors, you know you mentioned that high levels of albumin are associated with good outcomes, but I mentioned in the beginning that unfortunately low levels of albumin are associated with morbidity and mortality, as well. There are a lot of studies that have made that link, correct?
Dr. Kam Kalantar: Yes, the studies are relatively consistent in that low serum albumin is a predictor of poor outcome, and the opposite also. High serum albumin is a predictor of longevity. And the consistency of these studies has been remarkable, especially in dialysis patients. It's interesting that in the general population, also, all that emerging data suggests that your serum albumin, that is in myself and yourself, is a very important predictor and determining factor. But in dialysis patients, in patients on dialysis, this is very important market. That means if your serum albumin is low, we have a high-risk situation, and if serum albumin of my dialysis patient is higher, the higher the better, to the point that there is no way I can say that I'm satisfied, I try my best to increase serum albumin higher in all of my patients on dialysis.
Brad Puffer: And what is that target range that you're seeking, and can too much be a bad thing?
Dr. Kam Kalantar: Yeah, I don't think I'm going to say that too much is not a bad thing, but first of all, we have a challenge because only 30 to 40% of our patients have a serum albumin above 4.0 grams per deciliter. So, this is answering your question, “What is the target threshold, normal serum albumin?” Most laboratory centers are described as 3.5 to 5.7. But I'm here to say, what is not coming from me, but coming from the literature over the past 30+ years, as well as the experience, that we would like our dialysis patients to have a serum albumin at least above 4.0. They run 30 to 40%, and if we are very lucky, maybe half of our patients achieve that goal.
Brad Puffer: And why is it so hard to maintain that albumin for dialysis patients?
Dr. Kam Kalantar: Well, dialysis patients, patients on dialysis, are dealing with many other problems. They have comorbid states. They have other problems: infection, inflammation, also protein-energy wasting (PEW) and, on top of that, they receive dialysis therapy, and if you are not careful with their dialysis therapy, their dialysis membrane exhorts to maintain and preserve that protein store or could be also a gateway to losing more albumin.
Brad Puffer: We talked about how there's more to preserving albumin than just nutrition. Can you talk about some of those other factors? And my understanding is that even dialyzers can play a role, correct?
Dr. Kam Kalantar: That's exactly what I was trying to mention or go over. Why? Because this is your dialysis patient, the dialysis patient is coming here, and on average, most of these patients undergo three times a week dialysis. Of course, there are also twice weekly dialysis patients, there are four times or five- times-a-week dialysis patients. But, as seen on average three times a week, a patient comes to the dialysis center for three to four and a half hours of dialysis therapy. If the choice of dialysis membrane is not correct, then we have added yet another risk factor for low albumin, which is called hypoalbuminemia. That means the dialysis membrane, which is supposed to be there to provide clearance to the patient, now could become a source of loss of albumin.
Brad Puffer: Well, you've studied the topic in depth. I mentioned in my intro that you actually were the lead author of an article that published in the International Journal of Nephrology and Renovascular Disease called “Slipping Through the Pores.” What was the biggest takeaway of your study? I know you spent some time looking at dialyzers.
Dr. Kam Kalantar: Yes, looking at different types of dialyzers, and the dialyzers for example that are currently available, we're very proud and pleased to use those that are available in our dialysis centers as compared to also certain dialysis membranes that are being manufactured for certain indications. So here, it is very important to really understand what the indication of some of these dialysis membranes are, and what the challenging aspects or some of the drawbacks of some of these are. So, the study you are talking about, this is a study where we reviewed five other studies. That means our goal was to put together the results of five other studies comparing high flux dialysis membranes. High flux dialysis membranes are what we are using in our dialysis centers, as compared to a new generation of dialysis membranes that are considered to have a high level of permeability, and it's allowing more of these middle molecules to cross. And as I said, those things have certain indications. For example, let's say if you have a patient with abnormal proteins, such as multiple myeloma, it's a blood cancer or bone marrow cancers, then probably this is where I could use those dialysis members with larger pores.
But would I be happy to use these membranes, with a high level of permeability for routine dialysis treatments of my patients? That's a very important question, as this question not only pertains to me and my dialysis patients, but to all 12,000 nephrologists and all 550,000 dialysis patients in the United States and all other countries. So, this is essentially a very important portion of my responsibility to make sure that the high-flux dialysis I prescribe to my patients do the job, and that I’ve not switching that to something that could lead to loss of albumin for these dialysis patients.
Brad Puffer: Well, I think that's the key point you make there because I'm sure we can't 100% say, you know, the dialyzer is causing the increase in albumin, but you know that serum albumin can go up, especially with the right nutrition and other interventions, with a high-flux dialyzer. But what you're saying is you're not necessarily seeing that with these other dialyzers. In fact, you're seeing loss, regardless. So, I assume as a physician, if you're working closely with your patients and you're getting their nutrition the right way to increase albumin, but a dialyzer is then stripping that albumin away, that's a problem for you.
Dr. Kam Kalantar: That's a serious problem. Let me tell you why: Because I do everything in my power as you, again, absolutely measure from nutrition to providing adequate protein, and also avoiding or treating inflammation, treating infection and anything that could interfere with albumin generation and maintenance. So, I do all these things and it would be heartbreaking that while I'm also providing dialysis therapy, that the choice of membrane is the one that could lead to the loss of this asset. That means serum albumin, this is the protein. This is the most important protein-based asset that my patients have. So, it's an important level of responsibility and accountability for us as dialysis care providers and nephologists to ensure that we do not cause any risk by considering or ordering dialysis membranes that could also be used for certain symptoms. As I said, maybe those highly permeable or protein-leaking dialyzers are very good for certain disease states, rare disease states, such as multi-level, but would I help my patients by providing these protein-leaking dialyzers to everybody, or to most of our patients. That's actually very important and serious question for all of us.
Brad Puffer: Albumin may be something that most physicians are familiar with, they're comfortable talking about. Do you think as many thinks about this loss as much as they should, and what would your recommendation be to physicians about albumin?
Dr. Kam Kalantar: Yes, actually a good dialysis membrane should not lead to any loss of albumin. Serum albumin should maintain if I use the high-flux dialyzers that are currently available and are being used, including in our dialysis center. However, there is a discussion about use of the so-called highly permeable or middle cutoff dialyzers and studies are relatively consistent that they lead to loss of albumin levels, and sometimes justify that there are so many other good benefits coming out of this membrane, and let's ignore that loss. That's the price, and I wouldn't agree with that. Why should we pay a price? I mean, this is a very expensive price. This is a very high price if I want to do something for my patients, at the cost of losing albumin, during dialysis therapy.
Brad Puffer: You've been pretty passionate about this issue for a long time. Do you think other physicians are starting to realize how important this issue is?
Dr. Kam Kalantar: I believe so. As I said, studies have shown consistently - if there is one marker, if we are going to choose one laboratory measure as the strongest predictor of survival and longevity, that’s serum albumin. Of course, there is also hemoglobin, phosphorus, calcium, and other things. But the one that has been consistently associated with the strongest prediction of survival is serum albumin. I'm not the only one who is proud of the serum albumin levels of my patients, and I’m not the only one who has used the keyword passion. We should all be passionate about this because these are patients. The patient has trusted us. They have chosen dialysis for their hopes and longevity, and I have every reason to ensure that they achieve those goals.
Brad Puffer: What would be your biggest piece of advice to physicians about how they can even better incorporate discussions of albumin and thinking about this issue, especially when talking to their patients.
Dr. Kam Kalantar: We nephrologists, we should continue to provide the great care that my colleagues are providing, ensuring adequate nutritional status, good nutritional status, and adequate nutritional supply, high protein diets, supplements, if necessary, timely and effective treatment of infections and inflammatory causes of problems. But at the same time, we should know that nothing should be justified by providing something greater at the expense of the loss of protein, which is albumin. So, we should really continue to be passionate about this. We should be aware of the consistency of the data, and we should do the best for our patients. That means ensuring that their serum albumin levels remain high.
Brad Puffer: Well, I think that's a great way to end this conversation, Dr. Kalantar. It's really been interesting and thank you so much for joining us to discuss your research and passion for this subject.
Dr. Kam Kalantar: My pleasure, thank you.
Brad Puffer: And to our audience, thank you for joining us. Please know that your feedback is always welcome. If you have comments on today's episode, topics of interest to you, or speakers you want to hear from, let us know by clicking the Feedback link featured on the Field Notes website on FMCNA.com. And don't forget you can find Field Notes on the Apple Store, or Google Play, or right here at FMCNA.com, where you can also find our annual medical report and other featured articles. We hope you'll come back and join us as we have many more topics to discuss in the weeks ahead. Until next time, I'm Brad Puffer, and you've been listening to Field Notes by Fresenius Medical Care. Take care everyone.