Rapid Effect of nCPAP Therapy on Circulating Plasma Leptin in OSAS Patients

Obstructive sleep apnea syndrome (OSAS) is a problem of obese patients. Leptin prevents fat deposition in adipose tissue and insulin reduces plasma glucose, but levels of these hormones are sometimes high in obese patients with OSAS. Thus, leptin and insulin do not function properly in OSAS, and increase resistance to leptin and insulin may cause paradoxical state, that is, leptin and insulin resistance. The present study investigates the rapid effect of nasal continuous positive airway pressure (nCPAP) ventilation on serum leptin and insulin levels in OSAS. Levels of plasma leptin and insulin at four sampling points a day decreased in OSAS patients (*p<0.05, n=10) by nCPAP. Nocturnal mean-nadir arterial oxygen desaturation (nmSaO2) correlated with plasma leptin levels in OSAS patients (*p<0.05, n=10). Nasal CPAP did not affect circulating soluble leptin receptor levels in OSAS patients. These findings indicate that leptin and insulin are related to nocturnal hypoxia in OSAS patients, and that nCPAP have a possibility of improving leptin and insulin resistance.