Association of sleep fragmentation with general and abdominal obesity: a population-based longitudinal study

To evaluate the causal relationship between sleep fragmentation (SF) parameters with general and abdominal obesity in free-living conditions.

SF parameters were assessed by ActiGraph accelerometers for 7 consecutive days. Obesity was measured at baseline and 1-year follow-up with InBody S10 body composition analyzer.

At baseline, the mean age of the study population was 18.7 years old (SD = 0.9) and 139 (35.7%) were male. Each 1-unit increase of baseline sleep fragmentation index (SFI) was associated with 0.08 kg/m²-increase of body mass index (BMI) (95% CI: 0.03, 0.14), 0.20%-increase of percentage of body fat (PBF) (95% CI: 0.07, 0.32), 0.15 kg-increase of fat mass (FM) (95% CI: 0.03, 0.27), 0.15 cm-increase of waist circumference (WC) (95% CI: 0.03, 0.26) and 0.91 cm²-increase of visceral fat area (VFA) (95% CI: 0.36, 1.46) at the 1-year follow-up. In addition, each 1-unit increase of baseline SFI was associated with 15% increased risk of general obesity (OR = 1.15, 95% CI = 1.04-1.28; p = 0.006) and 7% increased risk of abdominal obesity (OR = 1.07, 95% CI = 1.01-1.13; p = 0.021) in the following year.

Fragmented sleep is independently associated with an increased risk of both general and abdominal obesity. The result highlights SF as a modifiable risk factor for the prevention and treatment of obesity.