Association of Sleep-disordered Breathing and Blood Pressure with Albuminuria: The Nagahama Study.

Rationale: Although sleep-disordered breathing (SDB) may increase urinary albumin excretion (UAE) by raising nocturnal blood pressure (BP) in addition to diurnal BP, the correlation has not been investigated in a general population. Objectives: To evaluate the relationships among UAE, SDB, and BP during sleep in a large population cohort. Methods: Among 9,850 community residents, UAE was assessed by the urinary albumin-to-creatinine ratio (UACR) in spot urine. Sleep duration and SDB were evaluated by a wearable actigraph and pulse oximeter, respectively. We calculated the actigraphy-modified 3% oxygen desaturation index (Acti-3%ODI) by correcting the time measured by pulse oximetry according to sleep duration obtained by actigraphy. Furthermore, participants were instructed to measure morning and sleep BP at home by a timer-equipped oscillometric device. Results: Measurements of sleep parameters, UAE, and office BP were obtained in 6,568 participants. The multivariate analysis that included confounders showed a significant association of Acti-3%ODI with UACR (β = 0.06, P < 0.001). Furthermore, a positive interaction between office systolic BP (SBP) and Acti-3%ODI for UACR was found (β = 0.06, P < 0.001). Among the 6,568 persons enrolled in the analysis, 5,313 completed measurements of BP at home. In this cohort, the association of Acti-3%ODI with UACR remained significant (β = 0.06, P < 0.001) even after morning and sleep SBP were included in the analysis. Furthermore, a mediation analysis revealed that 28.3% (95% confidence interval, 14.9-41.7%; P < 0.001) of the association of Acti-3%ODI with UACR was explained by the mediation of morning and sleep SBP metrics. Conclusions: SDB and office SBP were independently and synergistically associated with UAE, which is considered a risk factor for chronic kidney disease and cardiovascular events. SDB may raise UAE not only by increasing BP but also by involving other pathologic pathways.