Updates in the Management of Chronic Kidney Disease and Type 2 Diabetes - Episode 2

Assessment and Staging of Chronic Kidney Disease

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Diagnostic criteria and special considerations of nephrologists when assessing patient kidney function and diagnosing chronic kidney disease.

Neil B. Minkoff, MD: We already started talking a little about the staging—Dr Agarwal started with that—and the assessment of disease severity. But Dr Bakris, you spend a lot of your time running the hypertension center. What are some of the things that you look for in terms of overall staging and assessment of disease severity? And how do you go about doing so?

George L. Bakris, MD: Thank you for that question. I want to build on what both Rajiv and Gene said, because it’s important for the clinician to understand, No. 1, if you’ve measured GFR [glomerular filtration rate], you’ve done an incomplete job of knowing what the kidney stage is. Because without albuminuria, you really don’t know. There are people who have GFRs of 70 mL/min who have 4 g of proteinuria. You cannot tell me that’s normal kidney function. It’s important to understand the staging. It’s critically important to do both.

Once you’ve established the stage, what are we looking at? The people who get referred to me are basically people with diabetes who have elevated creatinine levels, albumin in their urine, and poor blood pressure control. Diabetes is the No. 1 cause of kidney failure in the world. That includes Asia, the United States, South America, etc. Hypertension is No. 2. If you take those 2 problems together, it accounts for approximately 75% of kidney failure in the world. And that’s poorly controlled hypertension, not just hypertension.

A family history of kidney disease is critically important. It’s cheap genetics, and you need to ask about it. In addition to that, the other remaining causes are not that common. Polycystic kidney disease and IgA [immunoglobulin A] nephropathy round out the next 10% to 15% of kidney failure in the world. Diseases like glomerulonephritides, focal glomerulosclerosis, and other diseases well known to nephrologists aren’t that common if you look at the bigger scope of things. It’s critically important to identify stage and intervene as aggressively as possible.

Neil B. Minkoff, MD: Let me follow up with that. If you’re talking to somebody like me who has been a primary care physician [PCP], and you’re getting us to look at both the filtration rate, the eGFR [estimated glomerular filtration rate], and the albuminuria, how do you stratify those? I’m trying to figure out how to incorporate that into a PCP practice.

George L. Bakris, MD: The easiest possible thing is to get a copy of the KDIGO [Kidney Disease: Improving Global Outcomes] heat map. KDIGO is the international guideline for nephrologists. There’s a heat map that was developed in 2002, and it has been perfected through the years. It’s called a heat map because it’s different colors. It has the GFR staging on the left, the albuminuria staging across the top, and there are different colors. If you’re in the green boxes, you have nothing to worry about. But then there’s yellow, which means there’s something to worry about and you’ve got to keep an eye on it. There are orange boxes, where you’re in trouble and you’ve got to keep a close eye on it. Then there are the red boxes. The red boxes mean you’re there, you’ve got high cardiovascular risk and established kidney disease. Let’s not forget that cardiovascular risk goes with this. It’s not just the kidneys. You can define cardiovascular risk as the lower your kidney function, the higher the stage of kidney disease, the greater the cardiovascular risk. I show the heat map to every patient so they get a picture. It’s important to share this information with the patient. This isn’t something that just you should know. The patient should know, and that will improve adherence because they know it’s important and will listen to you.

Neil B. Minkoff, MD: Dr Wright?

Eugene Wright Jr., MD: George, I’d like to comment on what you said about showing that to patients. We’ve started to try that with a couple of patients, and it’s amazing how the light goes off because people recognize green is good, red is bad. Once you show them where they are in there, their next question is, “How do I move from where I am to a safer place?” They perceive green as being safe. It’s a great opportunity in a short amount of time to really explain what you’ve talked about with the staging. If it becomes a discussion tool with the primary care clinician, it enhances the patient engagement, and as you say, will hopefully lead to better adherence.

Transcript edited for clarity.