The Prevalence Of Metabolic Syndrome In Middle And Old People In Dalian And The Relationship Between Essential Hypertension And Insulin Resistance

Background & objectives:Cardiovascular disease (CAD) is the main cause of mortality in type 2 diabetes mellitus (T2DM). The metabolic syndrome (MS) is supposed to be the common pathway between T2DM and CAD. Insulin resistance (IR) is considered the core of MS. MS constellated with central obesity, dyslipidemia, hypertension, and hyperglycemia, carries a prothrombotic state and a proinflammatory state,and its consequences is development of coronary heart disease, stroke, type 2 diabetes and so on. The prevalence of MS increases with the development of economy,changes of lifestyle and increased aging population. In order to further understand the epidemic condition of MS and effective control DM and CAD risk, we investigated the prevalence of MS in retired institutional subjects older than 50-year in Dalian, China.Essential hypertension (EH) is an important component of MS, and is the risk factor for CAD. Its incidence and its associated mortality, morbidity are increasing. Patients with EH are often accompanied with IR. Most believe that IR is an independent risk factor for EH, but debates still exist. The relationship between IR and EH in subjects with DM or impaired glucose tolerance (IGT) has been certified. We aimed to study the relationship between IR and EH in subjects with normal glucose tolerance.Methods:900 subjects without known diabetes mellitus who attended the health examination (435 men and 465 women, mean age 63.5±7.2years) were selected. Demographic data and co-variables obtained include age, sex, history of present illness, history of past illness, blood pressure, waist circumference, fasting total cholesterol (TC), fasting total triglyceride (TG), fasting plasma glucose (FPG) fasting insulin (FINS). In subjects without known diabetes mellitus, 75g oral glucose tolerance test (OGTT) was given, and then the 2 hour postprandial plasma glucose (2hPG), 2 hour postprandial insulin (2hINS) were measured. The body mass idex (BMI), homeostasis model assessment of insulin resistance idex (HOMA-IR), homeostasis model assessment ofβ-cell function (HOMA-β) were calculated.In accordance with the diagnostic criteria for MS established by the International Diabetes Federation (IDF) in 2005, we analyzed the prevalence of MS and single metabolic abnormality. 418 subjects with normal glucose tolerance were selected from the 900 subjects, then they were divided into hypertensive group (HTN, 106 cases) and normotensive group (NTN, 312 cases) according to the hypertension diagnostic criteria established by the Chinese Hypertension League (CHL).We evaluated the insulin resistance level and secretion function ofβcell of pancreatic islet, and compared the difference between the two groups. Multivariate logistic regression was taken between risk factors and EH. Non-normal distribution of the quantitative data firstly been converted into logarithm forms.Results:1. 55.22% of subjects had central obesity, 48.44% of subjects had newly diagnosed diabetes mellitus or impaired glucose tolerance, 50.22% of subjects had hypertension, 28.67% of subjects had hypertriglyceridemia. 241 subjects met the diagnostic criteria for MS and the prevalence of MS was 26.78%, of which MS patients in the central obesity combined with hyperglycemia, hypertension are the most, accounting for 68.05 % of MS. The prevalence of MS had increased from 25.87% to 30.77% with age increased.2. The prevalence of MS was different in different gender groups. The prevalence of central obesity and hypertriglyceridemia in female group was higher than in male group, while the prevalence of hyperglycaemia and hypertension in male group was higher than in female group (P<0.05). The prevalence of MS was 31.83%, 21.38% in female group and male group respectively(χ2﹦12.50, P<0.01).3. The age, waist circumference, BMI, TG, FPG, FINS, 2hINS of HTN group were significantly higher than those of NTN group(P<0.05). LogHOMA-IR in HTN and NTN was 0.31±0.25 and 0.19±0.22 (P<0.01). Multivariate Logistic regression analysis showed that age, BMI, TG, logHOMA-IR were positively related to EH, the partial regression coefficients was 0.085, 0.116, 0.416, 1.817 respectively, and the odds ratio was 1.089, 1.123, 1.517, 6.152 respectively.4. There was no significant difference of logHOMA-IR in various levels groups of EH (F=0.938, P>0.05), but the logHOMA-βin Grade III of EH defination was higher than it in Grade I and Grade II of EH (P<0.05).Conclusion:1. One third over 50-year subjects have MS in the selected population in Dalian, China. The prevalence of MS and central obesity is higher in women than in men, while the prevalence of hypertension is higher in men.2. Insulin resistance exists in patients with essential hypertension in those population of normal glucose regulation, and positively correlates with essential hypertension.