The Association Between Metabolic Syndrome And Cardio-cerebrovascular Disease And Total Mortality In Chinese Mongolian Population

Objective:To investigate the optimal cut-off points of waist circumference(WC) for identified metabolic syndrome(MetS); to analyze the association between MetS and cardio-cerebrovascular disease and total mortality in Chinese Mongolian population.Methods:A cross sectional study was carried out during2003-2004.32villages of Kezuohou and Naiman banners(counties)were selected as study fields, and all Mongolian people aged20or more were served as subjects. Demographic data and lifestyle factors were investigated, WC, hip circumference(HC) and blood pressure were measured and blood sample was collected for all subjects. Fasting plasma glucose(FPG), blood lipids, CRP (C-reactive protein) were examined for all subjects. In2008,2009and2010, a follow-up study was conducted for all subjects to collect the data about incidence of cardio-cerebrovascular diseases and total mortality.Receiver operating characteristic (ROC) analysis was used to find out the optimal cut-off points of WC to identify MetS. Multivariate Proportional Hazards Model was conducted to analysis the relationship between MetS, HC, CRP and multiple failure time(stroke, coronary heart disease and total mortality). HC and CRP were grouped according to quartiles, respectively. Epidata3.0software was used to establish a database, and all questionnaires were input after checking by two individuals. All p-values were based on a2-sided test and a significance level of0.05, and statistical analysis was conducted using SPSS17.0statistical software.Results:A total of2589participants aged20-84years old, were included in the analysis.1. In the study, the prevalence of MetS was20.9%among the Mongolian people. With adjustment for age according to the Fifth National Population Census, the prevalence was17.1%.2. Binary Logistic regression analysis was used to evaluate the association between WC and MetS components, for male and female respectively. With the increasing of WC, the Odds Ratios was increasing for1MetS components,2MetS components and≥3MetS components both in male and female. And the dose-response relationship between WC and the number of MetS components was statistically significant (trend test, all P<0.01). It indicated that WC was significantly associated with clustering of MetS components.3. With increasing cut-off points of WC, the Sensitivity and Negative Predictive Value dropt gradually for≥2MetS components while the Specificity and the Positive Predictive Value rose gradually. The WC cut-off point with the largest area under ROC curve was84cm in male and81cm in female, at which points the Youden Index was highest and the Sensitivity and Specialty were relatively higher. To consider recent studies in Chinese population that suggested cut-off points of WC at85cm for male and80cm for female, we suggested that the optimal cutoff points for WC were85cm for male and80cm for female among Chinese Mongolia population. Applying85cm and80cm to our field data, the results showed23.5%, and19.4%and26.4%for male and female respectively. The prevalence in male was now higher than the prevalence when90cm was used according to the IDF criteria.4. During follow-up, the cumulative incidence of cardio-cerebrovascular disease was5.64%, the incidence density was787.4/100000person-years; the cumulative mortality was4.44%, death density was620.2/100000person-years.5. Multi-factors Multivariate Proportional Hazards Model analysis showed that age, gender(men), history of hypertension, MetS, HC and CRP was associated with multilple failure time(cardio-cerebrovascular disease and total mortality).6. Multi-factors adjusted results showed that MetS was associated with multilple failure time(cardio-cerebrovascular disease and total mortality), and the hazard ratios(HR) and95%confidence intervals(95%CI) were1.33(1.02～1.74)(P=0.034) among Mongolian population.7. Multi-factors adjusted results showed that HC was associated with multilple failure time(cardio-cerebrovascular disease and total mortality). Compared with the lowest HC, the HR(95%CI) of higher HC(2,3and4quartiles) for multilple failure time were0.62(0.44～0.88),0.66(0.46～0.94),0.52(0.36～0.76), respectively(P=0.021～0.001) among Mongolian population.8. Multi-factors adjusted results showed that CRP was associated with multilple failure time(cardio-cerebrovascular disease and total mortality). Compared with the lowest CRP, the HR(95%CI) of higher CRP(3and4quartiles) for multilple failure time were1.63(1.21～2.20),1.58(1.15～2.17), respectively (P=0.001～0.005) among Mongolian population.9. By generating new variables, Multi-factors Multivariate Proportional Hazards Model showed that,(1) Stroke was associated with age, gender (men), history of hypertension, and the HR(95%CI) were as follows:2.22(1.92～2.56),2.12(1.38～3.25),2.34(1.50～3.65), respectively,(all P<0.01)(2) Coronary heart disease was associated with age, history of hypertension and MetS and the HR(95%CI) were as follows:1.66(1.38～1.99),2.09(1.05～4.16),2.17(1.22～3.86), respectively (all P<0.05)(3) Total mortality was associated with age, gender(men), HC(4quartiles) and CRP, and the HR(95%CI) were as follows:2.21(1.89～2.57),1.66(1.13～2.45),1.32(1.11～1.56),0.43(0.26～0.73), respectively(all P<0.05).Conclusion:1. There were higher prevalence of MetS and higher incidence of cardio-cerebrovascular diseases in Chinese Mongolian population.2. The recommended cut-off points of waist circumference for identifying MetS were85cm for men and80cm for women in Chinese Mongolian population.3. MetS was an important risk factor of coronary heart disease in Chinese Mongolian population.4. A larger hip circumference was inversely associated with total mortality in Chinese Mongolian population.5. CRP probably was an important risk factor of total mortality in Chinese Mongolian population.