Obstructive Sleep Apnea - Hypopnea Syndrome Serum Leptin Levels

Study objectives: To investigate the first night effects of nasal continuous positive airway pressure (nCPAP ) treatment on fasting serum leptin levels and study the possible mechanism of the hyperleptinemia in the obstructive sleep apnea-hypopnea syndrome (OSAHS ).Methods: 24 cases with OSAHS ( mean age 52.3±2.9 years, meanbody mass index 28.6±0.6 kg / m , mean apnea-hypopnea index 55.6 ±22.8 / h )established on basis of clinical and polysomnographic criteria were studied. Fasting venous blood samples were obtained from the 24 cases with and without 1-night nCPAP treatment. Serum leptin levels were examined by Enzyme-Linked Immunosorbant ( ELISA ) and compared between pre- and post- nCPAP treatment. The correlations between serum leptin levels and body mass index ( BMI ), neck circumference, waist circumference, diastolic / systolic blood pressure, AM, the minimum and mean blood oxygen saturation were analysed. Results:1 Serum leptin levels in patients with OSAHS correlated positively with BMI(p=0.005), neck circumference(p=0.005), waist circumference(p=0.004) , diastolic blood pressure (p<0.001) andAHI (p-0.024) significantly. Multiple stepwise regression analysis identified waist circumference and diastolic blood pressure as independent correlates(p<0.001) .2 The correlations between serum leptin levels and age, systolic blood pressure, the minimum and mean blood oxygen saturation were not significant (p>0. 1) .3 The first night of nCPAP treatment significantly decreased the serum leptin levels, diastolic / systolic blood pressure and heighten the minimum blood oxygen saturation in patients with OSAHS (p<0.001) . The decrease in serum leptin levels was not correlated with the changes in the others.Conclusion: Waist circumference and diastolic blood pressure independently correlated with hyperleptinemia in the patients withOSAHS. The degree of obstructive sleep apnea-hypoventilation (OSAH) positively correlated with serum leptin levels, but not an independent correlate. The first night of nCPAP treatment significantly decreased the serum leptin levels in patients with OSAHS .