The Chang And Significance Of Leptin In Obstructive Sleep Apnea Hypopnea With Metabolic Syndromes

1 Background and ObjectiveObstructive sleep apnea hypopnea syndrom (OSAHS) is a common chronic sleep-related breathing disorder.Patients in sleep on airway obstruction or appearing to collapse, snoring,breathing shallow,repeating low oxygen and sleep structure disordering cause a serious threat to human health.Currently, more and more scholars and experimentals point that OSAHS and metabolic syndrome (MS) have the close relationship:the high concurrent incidence rate and the coexisting greatly increasing the risks of cardiovascular disease.Among them, obesity is their common important feature.Obese person by increasing the adipose decomposing and fat cells absorbing fatty acid etc pathways causes insulin resistance (IR). IR is considered to be one of the important pathogenesis of MS and the common foundation in various metabolic risk factors. Have now think that adipose tissue is an important endocrine organ, which secrete plenty infection promoting or inflammation factors. Among them, leptin can control weight and regulate fat distribution, besides that, leptin still closely relates with insulin resistance[1,2],sugar metabolism, lipid metabolism disorders and hypertension. This study has controlled the gender and age factors.Investigating the changes of serum leptin levels among each groups and the correlations between leptin and insulin resistance, hypertension, etc.The aim is to analyse the probable impacts of leptin in occurrence and development process of the pathophysiological of OSAHS and MS.2 Object and Methods2.1 The object and the method:OSAHS group(n=40 cases) and OSAHS with MS group(n=30 cases). Fourty non-OSAHS men were matched with OSAHS group for body mass index(BMI) and age. OSAHS group were divided into three sub-groups by apnea-hypopnea index(AHI) and lowest pulse oxygen saluration(LSpO2),named mild group(n=12 cases), moderate group(n=14 cases) and severe group (n=12 cases).Measured the height, weight,neck circumference(NC), waist,hip, waist-to-hipratioWHR) and BMI.They measured serum leptin by the enzyme-linked immunosorbent assay(ELISA).Fasting blood glucose(FBG),leptin,true insulin (TI) triglyceral (TG),cholesterol (Chol) were measured in First Affiliated Hospital of Zhengzhou University's Laboratory.Insulin resistance was assessed by Homeostasis Model Assessment method (HOMA-IR).Polysomnography used Sandman Elite Polysomnography system produced by Tyco company in America and blood pressure including systoblic blood pressure (SBP) and diastolic blood pressure (DBP) were measured by standard mercury column cuff sphygmomanometer.2.2 Statistics processing:Experimental datas were dealed with Statistic Package for Social Science 17.0. Measurement datas were expressed by x±s.To compare the means between two groups used t test.The SNK-q inspection was used to comparing means between multiple groups.Correlations analysis between the two variables used the method of Spearman rank correlation analysis and multiple stepwise regression analysis for independent related variable selection.Alpha equaling 0.05 is inspection standards.3 Results3.1 The OSAHS group and its with MS group had a significantly greater WHR, SBP, DBP,FBG,HOMA-IR and AHI (P<0.05). OSAHS with MS group subjects had higher TI,TG,Chol levels (P<0.05) than non-OSAHS group and higher AHI (P<0.05),lower LSpO2(P<0.05) than OSAHS group.3.2 The OSAHS group and its with MS group had a significantly higher circulating leptin levels than non-OSAHS group (P<0.05). And leptin levels in OSAHS with MS group also were higher than in OSAHS group (P<0.05).Severe OSAHS group and moderate OSAHS group had significantly increased leptin levels compared with mild OSAHS group (P<0.05) and severe's higher than moderates.3.3 In OSAHS group, serum leptin levels correlated positively with AHI, HOMA-IR, BMI and TI(P<0.05),negatively with LSpO2(P<0.05). In OSAHS with MS group serum leptin levels correlated positively with AHI, HOMA-IR, BMI, NC, WHR, SBP, FBG,TG and TI (P<0.05),negatively with LSpO2(P<0.05),multiple stepwise regression analysis identified BMI(P=0.004),HOMA-IR (P=0.013) and AHI (P=0.022)as independent correlates.3.4 The blood pressure(in the morning) was higher in OSAHS group than non-OSAHS control group (P<0.05); Logistic Regression analysis showed that BMI(P=0.003) and leptin(P=0.024) were the independent correlates in development of the HT.4 Conclisions4.1 The changes of leptin relevant to the severity of OSAHS and participate the pathophysiological prosess of OSAHS and closely relate with the occurrence of IR,obesity and hypertension.4.2 The chang of leptin is probably the important related factors between OSAHS and MS.