Glomerular filtration rate in endurance athletes

Area of Science:

• Sports Medicine
• Nephrology
• Biochemistry

Background:

• Creatinine-based estimates of glomerular filtration rate (GFR) are used to assess kidney function.
• Interpretation of biochemical tests in athletes requires specific considerations.
• Limited data exist on the use of GFR estimation equations in endurance athletes.

Purpose of the Study:

• To evaluate the performance of the Modification of Diet in Renal Disease (MDRD) equation for estimating GFR in professional and amateur cyclists.
• To investigate the relationship between exercise intensity and estimated GFR in athletes.

Main Methods:

• The study included 76 professional male cyclists, 71 amateur male cyclists, and 65 healthy sedentary controls.
• Glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease (MDRD) equation.
• Serum creatinine levels and estimated GFR were compared across the groups.

Main Results:

• Sedentary subjects had higher serum creatinine and lower estimated GFR compared to both amateur and professional cyclists.
• Estimated GFR was significantly higher in cyclists than in sedentary controls.
• Higher daily physical exercise intensity was associated with lower serum creatinine and higher estimated GFR.

Conclusions:

• The MDRD equation should be used cautiously when interpreting GFR estimates in athletes.
• Factors such as the intensity and type of physical exercise must be considered when using the MDRD equation in athletic populations.