Relationship between Obstructive Sleep Apnea and Diurnal Leptin Rhythms

Study Objectives: Several studies have reported an association between obstructive sleep apnea and leptin, a hormone that influences satiety and body weight. We evaluated the relationship of leptin levels and the overnight change in levels with sleep apnea.Design: Cross-sectional analysis of data from a prospective cohort study.Setting: Case Western Reserve University General Clinical Research Center.Patients or Participants: A total of 138 individuals participating in the Cleveland Family Study -59% women, 45% African -American, with mean apnea-hypopnea index (AHI) of 6.9 (range 0-106)-were studied. Interventions: None.Measurements and Results: Serum leptin was measured at 10:00 pm to 11:00 pm and at 7:00 am to 8:00 am. Leptin levels in both the morning and evening were positively correlated with apnea-hypopnea index (AHI) in age-, sex-, and race-adjusted analyses (P 15 was associated with a 23% increase in leptin ratio.Conclusions: These findings suggest that sleep apnea may suppress secretion of leptin in the morning. Alternatively, the relative elevation in evening leptin may influence apnea pathogenesis.