Circadian Alignment, Cardiometabolic Disease, and Sex-Specific Differences in Adults With Overweight/Obesity

Context: Circadian disruption promotes weight gain and poor health. The extent to which sex plays a role in the relationship between the circadian timing of behaviors and health outcomes in individuals with overweight/obesity is unclear. Objective: We investigated the sex-specific associations between circadian alignment and cardiometabolic health markers in females and males with overweight/obesity. Methods: Thirty volunteers with overweight/obesity (15 female; body mass index ≥25.1 kg/m²) underwent an evening in-laboratory assessment for dim-light melatonin onset (DLMO), body composition via dual energy x-ray absorptiometry, and a fasted blood sample. Circadian alignment was determined as the time difference between DLMO and average sleep onset over 7 days (phase angle), with participants categorized into narrow/wide phase angle groups based on median phase angle split. Due to known differences in metabolic markers between sexes, participants were subdivided based on sex into narrow and wide phase angle groups. Results: Males in the narrow phase angle group had higher android/gynoid body fat distribution, triglycerides, and metabolic syndrome risk scores, while females had higher overall body fat percentage, glucose, and resting heart rates (all P < .04). Furthermore, a narrower phase angle in males was negatively associated with android/gynoid body fat (r = −0.53, P = .04) and negatively associated with body fat (r = −0.62, P = .01) and heart rate (r = −0.73, P < .01) in females. Conclusion: Circadian disruption may not only promote a trajectory of weight gain but could also contribute to negative health consequences in a sex-dependent manner in those already with overweight/obesity. These data may have implications for clinical utility in sex-specific sleep and circadian interventions for adults with overweight/obesity.