Objective sleep, a novel risk factor for alterations in kidney function: The CARDIA study

Objective: To determine the association between objectively measured sleep and 10-year changes in estimated glomerular filtration rate (eGFR). Methods: From 2003 to 2005, an ancillary sleep study was conducted at the Chicago site of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Community-based black and white adults (aged 32-51 years) wore a wrist actigraph for up to six nights to record sleep duration and fragmentation. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI). Participants without history of cardiovascular or chronic kidney diseases, proteinuria, or hypertension at the 2000-2001 CARDIA examination were followed over 10 years (n = 463). eGFR was estimated from serum creatinine (eGFR_Cr) at the 2000-2001, 2005-2006, and 2010-2011 CARDIA examinations, whereas cystatin-C-estimated eGFR (eGFR_Cys) was measured at the 2000-2001 and 2005-2006 examinations. Generalized estimating equation regression and linear models estimated the associations of each sleep parameter with changes in eGFR_Cr and eGFR_Cys, controlling for cardiovascular and renal risk. Results: Sleep parameters were not related to 5-year change in eGFR_Cys. However, each 1 h decrease in sleep duration was significantly associated with a 1.5 mL/min/1.73 m² higher eGFR_Cr [95% confidence interval (CI), 0.2-2.7], and each one-point increase in PSQI was significantly associated with a 0.5 mL/min/1.73 m² higher eGFR_Cr (95% CI, 0.04-0.9) over 10 years. Conclusion: In this community-based sample, shorter sleep and poorer sleep quality were related to higher kidney filtration rates over 10 years.