Associations between poor sleep quality and different measures of obesity

Objective: Poor sleep may be a risk factor for obesity. Previous studies have mainly investigated the effects of sleep duration on body mass index, but research considering overall sleep quality and other anthropometric measures is scarce. The aim of this study was to examine the association between sleep quality and different measures of obesity (general obesity, abdominal obesity, body composition) in a population-based sample of adults.

Methods: The study included 753 participants aged 35-65 years from the BiDirect Study, conducted in Münster, Germany. Participants completed the Pittsburgh Sleep Quality Index (PSQI) on sleep characteristics. Weight, height, and waist circumference were measured by trained study nurses. Body composition (fat mass and fat-free mass) was assessed using bioelectrical impedance analysis. The cross-sectional relationship between sleep quality and measures of obesity was investigated using logistic regression analysis.

Results: Among the participants, 65.3% reported good (PSQI ≤ 5) and 34.7% poor (PSQI > 5) sleep quality. We observed a significant association of poorer sleep quality assessed by the continuous PSQI score with general obesity and high body fat (for both, odds ratio = 1.07, 95% confidence interval = 1.01-1.13), adjusted for socio-demographic and lifestyle factors. Further adjustment for depressive symptoms and somatic comorbidities attenuated the relationship. The observed association was mainly driven by the PSQI components sleep latency, sleep disturbances, and daytime dysfunction.

Conclusions: The present study suggests that poor sleep quality may predict obesity and high body fat mass among adults. However, a causal relationship still has to be confirmed by prospective studies with objective measurements of sleep and obesity.