Objective: To investigate the relationship between obesity and sleep architecture in postmenopausal women.
Methods: One hundred seven postmenopausal women from the Ambulatory of Integrative Treatment for Female Sleep Disorders were invited by telephone to participate in this study. Fifty-three completed the study. We included women aged 50 to 70 years, and excluded women on hormone therapy or missing data. The study consisted of two meetings, including a full-night polysomnography. Menopause status was confirmed by amenorrhea for at least 1 year. Anthropometric measurements included: body mass, height, body mass index (BMI), waist circumference, hip circumference, waist-to-hip ratio (WHR), and neck circumference. Participants were allocated into two groups according to BMI: nonobese group (BMI <30 kg/m) and obese group (BMI ≥30 kg/m).
Results: The obese group had significantly (P < 0.01) increased values of BMI, neck circumference, waist circumference, and hip circumference. WHR was similar between the groups (P = 0.77). Obese participants had significantly increased values of respiratory disturbance index (16.4 vs 9.3 n°/h) and apnea-hypopnea index (14.2 vs 5.6 n°/h). Rapid eye movement sleep latency was positively correlated to body mass (r = P < 0.01), BMI (P < 0.01), and hip circumference (P = 0.01). WHR was negatively correlated to sleep efficiency (P = 0.03). The linear regression model showed that BMI (P < 0.01) and WHR (P < 0.01) were positive predictors of rapid eye movement sleep latency.
Conclusion: In postmenopausal women, high BMI and abdominal obesity are sources of sleep disturbances, decreasing deep sleep, and sleep efficiency, while increasing the risk of obstructive sleep apnea.