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Kidney Diseases

Borderline Creatinine levels



I am a 56 year old male and exercise vigorously 5-6 times a week. I am in training for the squash nationals in March 2009 and regularly play in local squash tournaments and leagues. I regularly push myself to high levels of aerobic fitness. I also lift weights for better upper body strength.

Recently, a blood test showed a Creatinine level a bit high at 1.33. BUN is good at 14 and the Bun/Creatinine ratio is good at 11. I feel completely healthy and can still compete with men on the squash court 20 years younger. I was told that the higher Creatinine could be related to my regular vigorous exercise. Should I be concerned or should I visit a nephrologist? Thank you.


The answer to this question depends on your height, weight, and muscle mass.  It is indeed possible that a creatinine of 1.33 could be normal for a large, physically-fit, muscular male.  However, it is also possible that you have some decrease in renal function (for instance, if you have high blood pressure or atherosclerosis).  In the average 56 year old male, this level of creatinine would represent a loss of about 40% of normal kidney function and would be expected to cause no symptoms at all. 

You probably do not need to see a nephrologist at this point, but your primary physician should do a thorough history and physical exam, repeat the blood tests, do a urinalysis, and collect a 24-hour urine for creatinine clearance, which will allow a more accurate measurement of your kidney function.  If kidney function is decreased (creatinine clearance below 90 ml/min), then you should be referred to a nephrologist to find out why.

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Response by:

Mildred   Lam, MD Mildred Lam, MD
Associate Professor of Medicine
School of Medicine
Case Western Reserve University