Association of Cardiorespiratory Fitness and Hemodynamic Responses to Submaximal Exercise Testing With the Incidence of Chronic Kidney Disease: The Framingham Heart Study

Objective: To relate cardiorespiratory fitness (CRF) and hemodynamic responses to exercise to the incidence of chronic kidney disease (CKD). Methods: We evaluated 2715 Framingham Offspring Study participants followed up (mean, 24.8 years) after their second examination (1979-1983) until the end of their ninth examination (2011-2014). Participants (mean age, 43 years; 1397 women [51.5%]) without prevalent CKD or cardiovascular disease at baseline were included. We examined the associations of CRF and hemodynamic response to exercise with incident CKD using multivariable Cox proportional hazards regression with discrete intervals. Results: Compared with low CRF (first tertile), participants with moderate (second tertile) or high (third tertile) CRF had a lower risk of CKD (hazard ratios [95% CIs]: 0.74 [0.61-0.91] and 0.73 [0.59-0.91], respectively). Participants with chronotropic incompetence (hazard ratio, 1.38 [95% CI, 1.06 to 1.79]), higher exercise systolic blood pressure (hazard ratio per SD, 1.20 [95% CI, 1.07 to 1.34]), and impaired heart rate recovery (hazard ratio, 1.51 [95% CI, 1.08 to 2.10]) had a higher risk of CKD compared with those with chronotropic competence, lower exercise systolic blood pressure, and normal heart rate recovery, respectively. These associations remained robust when the exercise variables were mutually adjusted for. The third tertile of a standardized exercise test score comprising the statistically significant variables was associated with a higher risk of CKD compared with the first tertile (hazard ratio, 1.85; 95% CI, 1.45 to 2.36). Conclusion: Higher CRF and favorable hemodynamic responses to submaximal exercise in young adulthood may be markers of lower risk of CKD in later life.