Sleep fragmentation and the risk of obesity: The Sleep Heart Health Study

Objective: Sleep disturbances have been recognized as a risk factor for obesity. This study used polysomnography records to investigate associations between sleep fragmentation and obesity. Methods: Objectively measured sleep fragmentation data recorded by in-home polysomnography, including total arousal index (ArI-total), ArI in rapid eye movement (REM) sleep (ArI-REM), ArI in non-REM sleep (ArI-NREM), sleep fragmentation index, sleep efficiency (SE), and wake after sleep onset (WASO), were based on the Sleep Heart Health Study (2,835 men and 2,888 women with a mean [SD] age of 63.2 [11.2] years). Multivariable regression analyses were used to examine the relationship between sleep fragmentation and obesity. Results: Multinomial logistic regression showed that participants with obesity have a significantly higher ArI-total (odds ratio [OR] 1.018; 95% CI: 1.010-1.026, p < 0.001), ArI-REM (OR 1.010; 95% CI: 1.002-1.018, p = 0.009), ArI-NREM (OR 1.017; 95% CI: 1.009-1.024, p < 0.001), and WASO (OR 1.003; 95% CI: 1.001-1.005, p = 0.007) compared with those with normal weight. Furthermore, multiple linear regression analyses showed an obvious correlation between ArI-total, ArI-REM, ArI-NREM, SE, WASO, and BMI. Conclusions: The results revealed that ArI-total, ArI-REM, ArI-NREM, SE, and WASO were associated with obesity. The improvement of sleep fragmentation may contribute to decreasing the risk of obesity.