Insulin Resistance And Plasma Adiponectin Level In Patients With Obstructive Sleep Apnea Syndrome

PART 1 Obstructive sleep aponea syndrome,glucose intolerance and insulin resistance-a systematical reviewBackground and objectiveObstructive sleep apnea(OSA) is a chronic disorder characterized by episodic collapse of the upper airway accompanied by cessation(apnea) or reduction(hypopnea) of airflow that results in intermittent hypoxia and fragmented sleep.The strongest risk factor for both type 2 diabetes mellitus and OSA is obesity with a high visceral(central) fat distribution.The effects of OSA on glucose tolerance and insulin sensitivity have received increasing attention in recent years.Remarkable associations raise the possibility that OSA may be a novel risk factor for type 2 diabetes and/or,conversely, that chronic hyperglycemia may promote OSA.Whether the treatment of OSA may delay the development or reduce the severity of type 2 diabetes is another important question.In this article,we will review the current evidence from population, clinic-based,and interventional studies that links OSA to alterations in glucose metabolism and type 2 diabetes.MethodsA computerized bibliographic search of MEDLINE,OVID,ELSEVIER,CNKI and WANFANG data were performed for OSA and insulin resistance.Results1.61 articles met the inclusion criteria(40 with English and 21 with Chinese) 25 of 35 studies which have used objective measures of OSAS provide support for an independent link between OSAS,glucose intolerance,and insulin resistance.2.14 of 26 studies that used continuous positive airway pressure(CPAP) to treat insulin resistance indicated that CPAP was effective,but most of them didn't have control groups.Conclusions1.OSAS is independently associated with glucose intolerance and insulin resistance.2.However,randomized controlled studies of large sample are needed to identified.PART 2 Insulin resistance and plasma adiponectin level in elder patients with obstructive sleep apnea/hypopnea syndromeBackground and objectiveOSAS is a common sleep-related breathing disorder of which prevelance is 2%-4%.Researches have suggested that patients with OSAS had high risk of cardiovascular disease and metabolic disorders such as diabetis or hyperlipidemia.Early researches have indicated that insulin resistance and hyperinsulinemia in OSAS patients was led by central obesity.But further researches suggested the potential independent correlations between OSAS and IR.The adipose tissue regulates insulin sensitivity via secretion of several adipokines into the circulation.Adiponectin plays a very important role among these proteins due to its putative insulin-sensitizing and antiatherogenic properties.If insulin resistance in OSAS is not only caused by obesity,the abnormal level of adiponectin in serum may play an important role.Because of the high prevalence of OSA and IR in elders,this study is to investigate the course of serum adiponectin levels,as well as their possible role in the complex metabolic processes characterizing obesity, insulin resistance and sleep-disordered breathing.Methods82 elderly patients who came to Huashan sleep clinic for snoring were devided into 2 groups by PSG result:OSAHS group(59 patients) and snoring group(23 patients).Metabolic parameters of all these patients were measured,including fasting insulin and adiponectin.Compare the differences of insulin resistance and adiponetin levels between 2 groups. Simple correlations and multiple stepwise regressions were taken to explore the independent correlations of IR and/or APN with other metabolic parameters.Results1.BMI,waist circumference(WC),HDL and TG of OSAHS group were significantly higher than those of snoring group.The prevalence of hypotension,diabetes,hyperlipoidemia and cerebrovascular disease were higher in OSAHS group than in snoring group2.FBG,Fins,HOMA-IR and APN were significantly higherin snoring group.3.Simple correlation analysis showed BMI,WC,AHI,ODI,SaO2＜90%(%TST)had positive correlations and LsaO2 had negative correlations with HOMA-IR. But multiple stepwise regression analysis indicated that only BMI and SaO2＜90%(%TST) had independent positive correlations with HOMA-IR.4.Simple correlation analysis showed BMI,WC,Fins,HOMA-IR had negative correlations and AHI,ODI,SaO2＜90%(%TST) had positive correlations with APN level.But multiple stepwise regression analysis indicated that WC had independent positive correlations and SaO2＜90%(%TST) had independent negative correlations with APN level.Conclusions1.Insulin resistance level and plasma adiponectin level were higher in elderly patients with OSAS.2.Nocturnal hypoxia was independently correlated with insulin resistance in some hands.3.No independent correlation was discovered in AHI and insulin resistance.