Effects of Aging on the Renal Function after Physical Exercise

Abstract

PURPOSE: The effects of aging on renal function (RF) following exhaustive exercise are unknown. This study was conducted to investigate these effects on 352 healthy subjects after an exhaustive treadmill run. METHODS: The subjects were of both sexes, and ranged in age from 8 to 76 years. Urinary excretion of protein (uTP), blood lactate (bLA), blood pressure(BP) and creatinine clearance (Ccr) were measured as an index of glomerular nitration rate (GFR). RESULTS: Ccr was found to decrease significantly directly after exercise and to recover to its pre-exercise level 30–60 min later. Ccr in males under 25 years of age decreased to 55.3% of the pre-exercise level directly after exercise, while in males 25 to 50 years old and those over 50, Ccr decreased to 68.8% and 86.9%, respectively, of the pre-exercise level. Similar levels of decrease in Ccr were observed in females directly after exercise. The net decrease in Ccr([[Unsupported Character - #8895;]] Ccr) directly after exercise was remarkable in younger subjects, and it was found to decrease with aging. Nevertheless, no difference in [[Unsupported Character - &#8895;]] Ccr was found in subjects from 8 to 40 years of age. NetuTP measured 30 min after exercise also decreased in relation to aging. A significant coefficient of correlation (r=−0.695, p <0.001) was found between [[Unsupported Character -#8895;]] Ccr and maximum heart rate (HRmax). CONCLUSIONS: The present results indicate that the younger the subject, the longer he or she is able to run before reaching exhaustion. A remarkable decrease in Ccr, and increases in BP, bLA and HRmax were induced after exhaustive exercise by younger subjects.