The Changes Of Serum Nitric Oxide And Leptin Levels In Patients With Obstructive Sleep Apnea/Hypopnea Syndrome

Objective To explore the changes of serum Nitric Oxide and Leptin levels in patients with obstructive sleep apnea/hypopnea syndrome.Methods Polysomnography was performed 7 hours in 35 patients with OSAHS and 30 healthy controls. Blood pressure was measured and peripheral venous blood sample were obtained before and after sleep. Serum NO levels measured as serum nitrites and nitrates. Serum leptin level was measured by radioimmunoassay. Results (1)Serum NO levels were significantly lower in OSAHSsubjects(evening:OSAHS=51.3 14.2umol/L ;control subjects=65.5 16.1umol/L p<0.05.morning:OSAHS=36.3 13.2umol/L;control subjects=63.1 17.5umol/L p<0.01).Serum NO levels in the morning were significantly lower than in the evening in OSAHS(morning=36.3 13.2umol/L;evening=51.3 14.2umol/L p<0.01). (2)Serum leptin levels were significantly higher in OSAHS(OSAHS=6.24 1.51ng/ml;control subjects=4.41 1.72ng/ml p<0.01).(3)Diastolic blood pressure was significantly higher in the morning than in the evening in OSAHS(morning:DBP=89 12mmHg ;evening:DBP=74 14mmHg, p<0.01). (4) Multivariate analysis showed NO was negatively related to AHI (r=-0.392, p=0.001) Oxygen desaturation time(r=-0.375,p=0.003),and diastolic blood pressure(r=-0.354,p=0.004) and leptin was positively related to BMI(r=0.293, p=0.021),AHI (r=0.416, p=0.001 ), and Oxygen desaturation time(r=0.385, p=0.003).AHI was the strongest impact factor on serum NO and leptin levels. Conclusion (1)Serum NO levels in OSAHS patients were lower than in controls.Serum NO levels in the morning were lower than in the evening in OSAHS. (2) Serum leptin levels in OSAHS were higher than in controls. Besides obesity, OSAHS may also increased serum leptin levels. (3) Diastolic blood pressure in the morning was higher than in the evening in OSAHS.