Sleep Apnea and Kidney Function Trajectory: Results From a 20-Year Longitudinal Study of Healthy Middle-Aged Adults

Study Objectives: To determine whether sleep apnea, defined by polysomnography, accelerates kidney function decline in generally healthy adults not selected for sleep apnea or kidney disease. Methods: We performed a retrospective cohort study in 855 participants from the Wisconsin Sleep Cohort Study, a large 20-year population-based study of sleep apnea, who had at least one polysomnogram and serial measurements of serum creatinine over time. Sleep apnea was defined as an apnea-hypopnea index >= 15 or positive airway pressure (PAP) use at baseline. We compared the slope of estimated glomerular filtration rate (eGFR) change and odds of rapid eGFR decline (>2.2 mL/minute/1.73 m2/year) for those with and without sleep apnea. Results: The mean follow-up was 13.9 +/- 3.4 years. The cohort was 50.4 +/- 7.6 years, 55% male, and 97% white. The mean eGFR was 89.3 +/- 13.8 mL/minute/1.73 m(2) and 11% had sleep apnea. Overall, the mean eGFR change was -0.88 +/- 1.12 mL/minute/1.73 m(2)/year. Compared with those without sleep apnea, participants with sleep apnea had a 0.2 mL/minute/1.73 m(2)/year slower eGFR decline though this was not statistically significant (95% CI [-0.06-0.45], p = .134). When we excluded those on PAP therapy (n = 17), eGFR decline was even slower among those with sleep apnea (0.36 mL/minute/1.73 m(2)/year slower, 95% CI [0.08-063], p = .012). Those with sleep apnea had lower odds of rapid eGFR decline but this was not statistically significant, even after excluding PAP users. Conclusion: Among healthy middle-aged adults, the presence of sleep apnea at baseline did not accelerate kidney function decline compared with those without sleep apnea over time.