Glomerular filtration rate and albumin excretion after maximal exercise in aging sedentary and active men.
BACKGROUND
From 30 years onwards there is a linear reduction of renal function of about 0.41% per year. Aging induces progressive impairment of glomeruli leading to an increase in protein excretion. The purpose of the present study was to investigate the effect of maximal exercise on glomerular filtration rate (GFR) and albumin excretion in an aging population.


METHODS
This is a cross-sectional study from 213 healthy men, sedentary or endurance-trained, aged 20-30 and 50-80 years submitted to maximal exercise on a cycle ergometer. Blood and urine samples were obtained at rest and after the strenuous exercise. We evaluated the GFR by measuring creatinine clearance and the urine albumin excretion rate.


RESULTS
After exercise, the older adults had a lesser reduction in GFR (mean 12%) than the young participants (mean 28%). As compared to those at rest, the increase of postexercise albumin excretion rates was lower in older participants (mean 7-fold) versus the young population (mean 20-fold). It appears that the exercise impact on some renal functions is related to the absolute load imposed on the individuals (r2 = 0.693).


CONCLUSIONS
As far as GFR and urine albumin excretion are concerned, regular endurance training does not induce any signs of potential incipient nephropathy in a healthy aging population.
Poortmans
Jacques R
JR
Institut Supérieur d'Education Physique et de Kinésithérapie, CP 168, Université Libre de Bruxelles, 28 Avenue Paul Heger, B-1000 Bruxelles, Belgium. jrpoortm@ulb.ac.be
Ouchinsky
Michel
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000419:Albuminuria; D003404:Creatinine / Q000032:analysis; D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology; D016552:Ergometry; D015444:Exercise / Q000502:physiology*; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D012146:Rest / Q000502:physiology
D003404:Creatinine