Abstract 15954: Association of Cardiovascular Fitness and Chronic Kidney Disease in Later Life: The Cooper Center Longitudinal Study
Background: Chronic kidney disease (CKD) prevalence is increasing in the United States. Prior reports have shown an inverse relationship between physical activity and decline in kidney function in older adults. However, there are no reports addressing the relationship between objectively measured cardiorespiratory fitness (CRF) and CKD. The purpose of this study was to assess the association between mid-life CRF and later life CKD.
Methods: We included 16,240 participants, 78% men, enrolled in the Cooper Clinic Longitudinal Study (CCLS) between 1970 and 2009. CRF was estimated from treadmill time on a modified Balke protocol and then stratified into low fit (quintile (Q)1), moderate fit (Q2-3), and high fit (Q4-5) categories. Baseline data from the CCLS were linked to Medicare administrative claims data from the Center for Medicare and Medicaid Services (CMS). The primary outcome was the diagnoses of CKD in individuals ≥ 67 years of age, as defined by CMS. We used a Cox proportional hazard model to estimate the association between mid-life fitness and the development of CKD in later life while controlling for additional factors.
Results: There were a total of 1,608 CKD events over 104,871 person-years. As seen in Figure 1, low fit individuals had the greatest rate of developing CKD. After adjustment for age and gender, high fit individuals had a hazard ratio (HR) of 0.48 [95% confidence interval (CI) 0.41, 0.56]) for CKD compared to low fit. In a model adjusting for baseline age, gender, tobacco history, body mass index, blood pressure, glucose, and cholesterol, the association attenuated (HR 0.63 [95% CI 0.52,0.75]). Further adjustment for incident hypertension, diabetes, and atrial fibrillation had little impact on the hazard adjusted for baseline factors (HR 0.67 [95% CI 0.56, 0.80]).
Conclusion: In this generally healthy sample, higher mid-life CRF was associated with lower CKD risk in later life, independent of incident CKD risk factors.
- © 2013 by American Heart Association, Inc.