Research On The Changes Of Serum Resistin Levels In Patients With Obstructive Sleep Apnea-Hypopnea Syndrome

Objective: To explore the changes and clinical implications of plasma resistin levels in patients with obstructive sleep apnea-hypopnea syndrome(OSAHS). To analysize the correlation between plasma resistin and OSAHS, and to discuss the possible mechanism of resistin effect in the obesity and OSAHS.Methods: Polysomnography was performed in 30 obese OSAHS patients(obese OSAHS group), 30 obese subjects(obese group),and 28 normal healthy adults (control group) . Plasma resistin levels were measured by radioimmunoassay. At the same time their height, weight, neck circumstance (NC) , waist circumstance(WC),hip girth, body mass index(BMI), body fat percentage(BF%), waist to hip ratio(WHR), blood pressure, fasting blood glucose(FBG) and blood lipid were measured.Results: There was no significant difference in the age and the sex among the three groups. In both the obese OSAHS group and obese group,the BMI was higher than 25 and there was no significant difference in BMI.In comparison with the control (5．78±1．62 ng/ml) , the obese OSAHS group (8．48±1．44ng/ml, P <0．05) and the obese group(7．60±1．53ng/ml, P <0．05) had higher plasma resistin level. The difference of plasma resistin level between the obese OSAHS group and the obese group was significant (P <0．05) . Based on apnea hypopnea index(AHI), divide the obese OSAHS groups into high, medium and low subgroups. Plasma resistin level in the high AHI group (9．60±0．51 ng/ml)was higher than medium( 7．96±1．06ng/ml, P <0．01) and low AHI groups(6．90±1．32ng/ml, P <0．01) . Correlation analysis demonstrated that the fasting plasma resistin level was positively correlated with BMI, NC, WC, WHR, FBG, total cholesterol (TC) ,AHI and triglyceride(TG)(r=0．52, 0．66, 0．74, 0．52, 0．48, 0．59, 0．80, 0．46; P <0．05) ; and it was negatively correlated with high density lipoprptein cholesterol (HDL-C), and lowest arterial oxygen saturation(LSaO₂) (r=-0．52, r=-0．60; P <0．01) ; and not correlated with low density lipoprptein cholesterol( LDL-C), BF%, systolic blood pressure(SBP) and diastolic blood pressure (DBP). For the obese OSAHS group, a stepwise multiple linear regression analysis show a formula: resistin=6．244+0．052×AHI.Conclusion: Plasma resistin levels were significantly higher in obese OSAHS patients than in the normal control and the obese patients. The fasting plasma resistin level was positively correlated with BMI, NC, WC, WHR, FBG, TC and AHI; and it was negatively correlated with HDL-C, and LSaO₂．In addition to BMI, OSAHS may contribute to the increased plasma resistin levels. Plasma resistin levels increase as OSAHS becomes worse, therefore, it may be used as an important biological index to evaluate the severity of OSAHS.