| Background:To literature, no large prospective cohort study has examined the relationship of body mass index(BMI) and waist circumference to incident cardiovascular disease risk in Mongolians from farming and stockbreeding areas. In addition, the interaction of BMI and waist circumference on incident cardiovascular disease has been scarcely evaluated.Objective:1、To take knowledge of the incidence and distribution of cardiovascular disease amongst Mongolians from farming and stockbreeding areas.2、To take knowledge of the prevalence of obesity and its association with metabolic risk factors.3 、 To explore the relationship of BMI and waist circumference to incident cardiovascular disease and consequently provide epidemic evidence for cardiovascular disease risk prediction and control in populations.Subjects and Methods:1. Baseline investigation: A cross-sectional survey was conducted in 32 villages in 2 adjacent townships located in Kezuohou Banner(county) and Naiman Banner in Inner Mongolia in May to July of year 2002 and in Jun to September of year 2003, respectively. A total of 2589 participants aged 20 years and older were studied. Data on demographic characteristics, smoking and alcohol consumption, family history of cardiovascular disease, was obtained by administered questions. Blood pressure, height, weight, and waist circumference were measured for all participants according to standard methods. Fasting blood samples were taken 5ml in the morning and separated to plasma and serum in the field, and then were transported to laboratory under low temperature and frozen at-80℃, for subsequent determination of various biochemical indicators.2. Follow-up survey: We investigated 2589 subjects involved in the baseline study for 10 years follow-up from the baseline to the end of 2012 August. The outcome event was defined as the first occurrence of cardiovascular disease during follow-up. The outcomes were obtained by household survey, hospital medical records, and the death certificate of the Public Security Bureau.3. Statistical analysis: Epidata3.0 software was used to create a database. All statistical analyses were conducted using SAS 9.2 and SPSS 17.0 statistical software. All p-values were based on a 2-sided test and a significance level of 0.05.Results:1、Two of the 2589 enrolled participants were excluded for lacking key variables. Therefore, a total of 2587 participants including 1062 men(41.05%) and 1525 women(58.95%) were included in current analysis. The average age was 46.49 years old. There were 1066 central obese individuals(20.14%) and 694 individuals with a BMI ≥24 kg/m2(26.83%) including 521 overweight and 173 general obesity. Participants were categorized into 4 groups according to BMI and waist circumference status: 1461(56.74%) participants with a BMI <24 kg/m2 and without central obesity, 60(2.32%) participants with a BMI≥24 kg/m2 and without central obesity, 432(16.70%) participants with a BMI<24 kg/m2 and with central obesity, and 634(24.51%) participants with a BMI≥24 kg/m2 and with central obesity.2、Six participants were lost during the follow-up, and follow-up rate was 99.77%. After 9.2 years, there were 23887.18 person-years of follow-up, during the follow-up, 200 cardiovascular events occurred, cumulative incidence rate and incidence density were 7.73% and 873.55 per 100 thousand person-years, respectively. Among the 200 cardiovascular events, there were 124 stroke events accounting for a cumulative incidence rate of 4.79% and an incidence density of 541.60 per 100 thousand person-years, and 76 coronary heart disease events accounting for a cumulative incidence rate of 2.94% and an incidence density of 331.95 per 100 thousand person-years. In central obese participants, 99 participants developed cardiovascular events accounting for a cumulative incidence rate of 9.29% and an incidence density of 1049.22 per 100 thousand person-years, significantly higher than participants without central obesity(P < 0.05). In participants with a BMI ≥24 kg/m2, 48 participants developed cardiovascular events accounting for a cumulative incidence rate of 6.92% and an incidence density of 765.47 per 100 thousand person-years, not significantly higher than participants with a BMI <24 kg/m2.3、Participants with central obesity were more likely to have hypertension(OR: 2.03; 95%CI: 1.68-2.46), diabetes(OR: 1.78; 95%CI: 1.16-2.74), and dyslipidemia(OR: 2.04; 95%CI: 1.72-4.42) than those without central obesity. Similarly, participants with general obesity were more likely to have hypertension(OR: 4.76; 95%CI: 3.33-6.81), diabetes(OR: 2.12; 95%CI: 1.07-4.19), and dyslipidemia(OR: 3.37; 95%CI: 2.36-4.82) than those without general obesity. We did not find a significant interaction of BMI and waist circumference on hypertension, diabetes, and dyslipidemia in either additive or multiplicative models.4、We did not observe a significantly increased risk for cardiovascular events in participants with central obesity compared with those without central obesity(OR: 1.14; 95%CI: 0.85-1.53). Similarly, we did not find a significantly increased risk for cardiovascular events in participants with general obesity compared with those without general obesity(OR: 0.88; 95%CI: 0.57-1.36). No significant interaction of BMI and waist circumference on cardiovascular disease risk by using either additive or multiplicative model.5、Kaplan-Meier survival curve analysis showed a significant difference in incidence of cardiovascular disease among the four categories based on central obesity and BMI ≥24 kg/m2(Log-rank test, P<0.05).Conclusions:1 、 The incidence of cardiovascular disease was high among Mongolians and cardiovascular disease has been a major threat to health in local population.2、Central obesity and general obesity increased prevalent risks for hypertension, diabetes and dyslipidemia.3 、 Central obesity was highly prevalent among Mongolians. The incidence of cardiovascular disease was significantly higher in central obese individuals than those without central obesity.4. No significant interaction of waist circumference and BMI on hypertension, diabetes, dyslipidemia, and cardiovascular disease was found among Mongolians. |
PDF Full Text Request