Sleep fragmentation and incidence of congestive heart failure: the Sleep Heart Health Study

Study Objectives: Sleep fragmentation (SF) has been reported to be associated with cardiovascular risk. The aim of this study was to explore the relationship between SF and congestive heart failure (CHF). Methods: A total of 4,887 participants (2,256 males and 2,631 females; mean age of 63.6 +/- 11.0 years) from the Sleep Heart Health Study were included in this study. Incident CHF was defined as the first occurrence of CHF between baseline in-home polysomnography (PSG) and the end of follow-up. Objective assessments for SF, including sleep fragmentation index (SFI), arousal index (ArI), sleep efficiency (SE), and wake after sleep onset (WASO), were determined based on in-home PSG records. Multivariate Cox regression analysis was used to investigate the relationship between SF and incident CHF. Results: During an average of 10 years of follow-up, 543 participants with CHF (11.1%) were observed. Individuals with CHF had a significantly higher SFI, total ArI, and WASO and a lower SE than controls. After multivariate Cox regression analysis, SE (odds ratio [OR], 0.967; 95% confidence interval [CI], 0.955-0.978; P <.001), WASO (OR, 1.009; 95% CI, 1.006-1.012; P <.001), SFI (OR, 1.046; 95% CI, 1.007-1.086; P =.021), and total ArI (OR, 1.018; 95% CI, 1.000-1.035; P =.044) were found to be associated with the incidence of CHF in participants without hypertension. Conclusions: Objectively measured SF was associated with the incidence of CHF. The role of SFI, total ArI, SE, and WASO deserves further investigation.