Have a healthy in-shape patient with an elevated creatinine? Are you considering referring the patient to nephrology? Think again…

Slightly elevated creatinine levels that are between 0.01-0.15 above baseline are extremely common in athletic individuals. I see this all the time in practice and year after year as I monitor their labs, the creatinine baseline stays a little elevated if they continue to exercise regularly. I work out regularly and my creatinine is around 1.45-1.5… It has been since my mid 20s.

If you have a patient with a slightly elevated creatinine who is athletic, then do not worry about this as it is normal. People who put stress on their muscles regularly will have higher levels of creatinine in their blood as creatinine is a byproduct made in muscles, thus the more muscle mass a patient has, the higher the baseline creatinine will be.

So, if you have an otherwise healthy patient with a slightly elevated creatinine level, simply ask them “do you work out/exercise regularly?” If they do, then just keep a close eye on their kidney function to ensure it stays consistent. If it continues to rise, then further investigation is warranted.

Also, a high protein diet can contribute to this and athletes typically have a high protein diet.

As always, use your best clinical judgement as each patient presentation will be different.