Physical inactivity and chronic kidney disease in Australian adults: the AusDiab study

Physical inactivity is associated with cardiovascular risk however its relationship to chronic kidney disease is largely unknown. We examined the association between leisure-time physical activity and risk of chronic kidney disease in a prospective, population-based cohort of Australians aged ≥ 25 years (AusDiab).

The baseline sample included 10,966 adults (4951 males and 6015 females). From this sample, 6318 participants with complete baseline and 5-year follow-up urinalysis and serum creatinine measurements formed the study population for longitudinal analysis. Self-reported leisure-time physical activity was measured using a validated, interviewer-administered questionnaire. Compared with sufficiently active individuals (≥ 150 min physical activity per week), those who were inactive (0 min/week) were more likely to have albuminuria at baseline (multivariate-adjusted OR=1.34, 95% CI 1.10-1.63). Inactivity (versus sufficient physical activity) was associated with increased age- and sex-adjusted odds of an estimated glomerular filtration rate <3rd percentile (OR=1.30, 95% CI 1.02-1.65), although this was not significant after multivariate adjustment (OR=1.17, 95% CI 0.91-1.50). Obese, inactive individuals were significantly more likely to have albuminuria at baseline (multivariate-adjusted OR=1.74, 95% CI 1.35-2.25), compared with sufficiently active, non-obese individuals. Baseline physical activity status was not significantly associated with longitudinal outcomes.

Physical inactivity is cross-sectionally associated with albuminuria prevalence, particularly when combined with obesity. Future studies are needed to determine whether this association is causal and the importance of physical activity in CKD prevention.