Soluble leptin receptor and insulin resistance as determinant of sleep apnea

OBJECTIVE: To investigate the possible associations between sleep apnea syndrome, hyperinsulinemia/insulin resistance and hyperleptinemia in subjects with different degrees of body mass index. DESIGN: To test for the presence or absence of sleep apnea syndrome in association with hyperinsulinemia/insulin resistance and hyperleptinemia. SUBJECTS: Twenty subjects with different body mass index (mean BMI 30.9+/-4.2). MEASUREMENTS: Insulin action and plasma soluble leptin receptor were measured by euglycemic hyperinsulinemic glucose clamp and by ELISA method, respectively. Occurrence of sleep apnea syndrome was assessed by clinical and nocturnal monitoring using a validated sleep apnea recorder. RESULTS: The apnea/hypopnea index (AHI) was positively correlated with plasma soluble leptin receptor (0.76; P < 0.001) and negatively with the degree of insulin-mediated glucose uptake (r= - 0.73; P < 0.001). In a multivariate analysis AHI was associated with plasma soluble leptin receptor and insulin mediated glucose uptake independently of age, gender, BMI, plasma leptin levels and PaCO2. CONCLUSION: Sleep apnea syndrome is associated with plasma soluble leptin receptor and insulin resistance independently of BMI.