Purpose: The purpose of this study was to evaluate the association of low aerobic fitness (AF), a quantitative phenotype primarily modified by physical activity, with the earlier markers of chronic kidney disease (CKD).
Methods: Maximum oxygen uptake (VO2max), the best index of AF, was estimated in an apparently healthy population of 34,769 adults without known history of diabetes and/or hypertension, and its association with renal function and albuminuria was analyzed retrospectively. VO2max was estimated using a cycle ergometer. Glomerular filtration rate was estimated with the Modification of Diet in Renal Disease Study equation. Glomerular hyperfiltration was defined as estimated glomerular filtration rate above the age- and sex-specific 97.5th percentile. Albuminuria was detected with dipstick urinalysis on fast morning urine and defined as ≥1+.
Results: VO2max levels were negatively correlated with the odds ratios of glomerular hyperfiltration in men (Ptrend = 0.039), not in women. VO2max was associated with glomerular hyperfiltration in young men (≤ the median age; Ptrend < 0.001), but not in old men. VO2max levels were negatively correlated with the odds ratio of albuminuria in men (Ptrend < 0.001), but not in women. These findings suggest that low AF may be associated with earlier markers of CKD in men. This association was not observed in women.
Conclusion: From the results of this study, it can be concluded that low AF may be a possible independent, modifiable risk factor for CKD in men.