September 13, 2007
Question from Jackson, Florida, USA:
How I can calculate my actual Glomerular Filtration Rate (GFR)? Is there a formula I can use? I've read that GFR should be adjusted for weight if body size is very different from average. I'm very concerned because my last two microalbumin/creatinine tests were high, over 50 and over 110. My endocrinologist says my GFR of over 60 has already been adjusted by the laboratory for weight. However, I go to an outside laboratory and their technicians never asked for my weight. I am a 51-year-old female and I weigh 98 pounds. Test results -- Urea Nitrogen: 14; Serum Creatinine: 0.8; Bun/Creatinine Ratio: 18; and Serum Albumin: 4.4
There are several methods of calculation or estimating GFR. I suggest you try the National Kidney Foundation web site. Estimated Glomerular Filtration Rate (eGFR) is a moving target. It can get better or it can get worse. I would be more concerned about microalbuminuria (microalbumin/creatinine ratio). If other non-diabetic causes can be excluded (there are many), this is suggestive of dysfunction of the lining of very tiny blood vessels (microvascular endothelial dysfunction) and can indicate early diabetic kidney damage. One should strive for the best control of major risk factors, e.g. A1c, blood pressure and blood fats (cholesterol, triglycerides, LDL, etc.).