Slightly increased Kidney Function?

Medical Q&A [Moderated]
1

Hi Docs - So for the last few years since I started seriously training and focusing on my nutrition my kidney function has been elevated slightly over the normal range in my bloodwork. My Doctors, as you guys have discussed a number of times, don’t really “get” strength training and the nutrition required for it. So when I explain that I’m on a high protein diet etc. they grow concerned. In any case my BUN on my last test was 26 (with the range ending at 25) and my Creatinine, Serum is 1.4 (with range ending at 1.3) I should also mention that I’m fairly muscular (209lbs, 33" waist ~12% BF) which I’ve heard explains elevated creatinine.

My question is basically is it normal to see elevated kidney function in strength training individuals with a high protein diet? Is it ok for it to stay like that? Or should I be attempting to get those numbers back into the range? Your input greatly appreciated. Thanks!

2

Turns out you have the same numbers that I do (also 1.4). When Creatinine is elevated, it is not indicative of increased kidney function but rather decreased function.

However, as you noted, this lab value can be falsely elevated in individuals with higher amounts of muscle mass. Conversely, it can be low in people with very, very low muscle mass (for example, I saw a patient this past week whose Creatinine was completely undetectable - her lab just read “< 0.15”. She didn’t have superhuman kidney function, but rather just had no muscle mass at all.

Of course, based on that single value alone I can’t guarantee that your kidneys are completely normal, but this is something that needs to be monitored over time. And It’s probably more related to your muscle mass than the dietary protein.

3

Makes sense. I’ll keep an eye on it. Thanks Doc!