Question: I am a 35 year old male. I am 70 inches tall and weigh around 195 pounds. I go the gym and exercise frequently—mostly weightlifting. I take 5g of creatine monohydrate daily. I also take 40 mg of pantoprazole daily and 40 mg of famotidine daily for acid reflux. I have been on this combination of acid reducers for nearly ten years.

A recent routine blood test indicates a serum creatinine level of 1.54, and an eGFR of 58. Looking back two years, my creatinine has been above range for the past two years (I have taken creatine supplements for as long). This was the first time, however, where mg eGFR dropped below 60. With the exception of a slightly high LDL and low vitamin D, all other labs were normal, including electrolytes, BUN, and BUN/creatinine ratio. Urinalysis was within range for protein (trace).

I am very concerned that I have developed chronic kidney disease, especially given my long course on pantoprazole. I have stopped taking creatine supplements, and expect to repeat the test. However, I am looking for some information as to whether my strength/gym routine and creatine supplementation may have boosted the serum creatinine (and lowered eGFR).

Thanks again Dr Anders. My GP ordered a repeat BMP in a two weeks. He, as you did, noted that creatine could certainly elevate the creatinine, and noted that weight lifting generally could play a role (I’ve added about twelve pounds since my prior physical a year ago—I assume muscle mass, as my waist size hasn’t changed, but my upper body musculature has grown in size).

I’ll have been off of the creatine supplements for about three weeks at that point. He also advised to stay hydrated (as this could further lower eGFR, and I tend to not drink the correct volume of water even during creatine use), and to cease weight lifting for some days prior to the blood test.

He raised the possibility of the pantoprazole potentially being an issue (I’ve taken it for years), but that I would have to discuss whether cessation was wise in consultation with my GI.

I appreciate that there are limits to what we can know based on the available data. However, I am trying to maintain an optimistic (but realistic) outlook. Given the favorable signs (clear urinalysis, other normal kidney function, electrolytes, etc.), would the balance of evidence favor something OTHER than CKD? A CKD diagnosis is obviously the greatest concern on my mind.