Study objectives: The aim was to assess associations between sleep duration, sleep stages, and central obesity in women.
Design: Cross-sectional study.
Setting: City of Uppsala, Sweden.
Participants: Population-based sample of 400 women (range 20-70 years).
Interventions: Full-night polysomnography and measurement of anthropometric variables.
Measurements and results: Sleep duration was inversely related to both waist circumference and sagittal abdominal diameter. Sleep duration remained inversely related to waist circumference (adj. beta = -1.22 cm/h; P = 0.016) and sagittal abdominal diameter (adj. beta = -0.46 cm/h; P = 0.001) after adjusting for potential confounders. Duration of slow wave sleep (SWS, adj. beta = -0.058 cm/min; P = 0.025) and REM sleep (adj. beta = -0.062 cm/min; P = 0.002) were both inversely related to waist circumference afteradjustments. Moreover,duration of REM sleep was inversely related to sagittal abdominal diameter (adj. beta = -0.021 cm/min; P < 0.0001). These associations were stronger in young women (age < 50 years).
Conclusion: An inverse relationship between short sleep duration and central obesity was found in women after adjusting for confounders. Loss of SWS and REM sleep may be important factors in the association between sleep loss and central obesity.