Prospective association of estimated cardiorespiratory fitness and risk of chronic kidney diseases.

Previous studies have reported that cardiorespiratory fitness (CRF) was associated with decreased risk of chronic kidney disease (CKD) in westerner. The aim of present study was to investigate the potential association between estimated eCRF (eCRF) and CKD risk in Chinese general population. A total of 5,199 participants from the China Health and Retirement Longitudinal Study were including in analysis. The sex-specific models including age, physical activity, resting heart rate, and waist circumference were used to calculate eCRF. Participants were divided into three subgroups according to age and sex-specific tertiles of eCRF. Cox proportional hazards regression models were used to examine the associations between eCRF and CKD. During 9 years of follow-up, a total of 511 respondents experienced CKD. After adjustment for potential variables, the hazard ratio (95% confidence intervals) for the tertile 2 and tertile 3 of eCRF was 0.80 (0.66-0.96) and 0.74 (0.60-0.92), respectively, compared with the lowest tertiles. Moreover, each 1-SD increase of eCRF was associated with 6% (95%CIs, 1-11%) decreased risk of CKD. Similar associations were also found in both male and female subgroups. When the current study calculated eCRF using body mass index instead of waist circumference, the highest tertiles of eCRF was significantly associated with decreased risk of CKD in overall and female participants. A higher eCRF was associated with a decreased risk of CKD in general Chinese population. Future well-designed prospective clinical studies are needed to verify our findings and to assess the effect of eCRF interventions in CKD prevention.