Epidemiological Study On The Risk Factors Of Cardiovascular Disease In Chinese Adults

Cardiovascular disease (CVD) constitutes a major public health problem in China and worldwide. Classical risk factors for coronary heart disease (CHD) and stroke have been identified, such as high blood pressure, tobacco smoking, hypercholesterolemia, obesity and age. The roles of major cardiovascular risk factors in the development of CHD or stroke are well established in Western populations. While for Chinese, the data are less extensive, especially lack of over twenty years prospective cohort study to investigate the magnitude of classical risk factors for CVD. Meanwhile, the prevalence of parental history of hypertension (PHHT) was high in China. Whether PHHT is associated with the risk of CVD? Whether PHHT could serve as an independent predictor for CVD? How about the quantitative association between PHHT and risk of CVD? There are three types of PHHT, both parents have hypertension, only father has hypertension, and only mother has hypertension. Which type of PHHT has much more association with CVD? All these questions are not well answered.This study is designed to solve the above issues based on two samples (male steelworkers of Capital Steel and Iron Company cohort, China National Hypertension Survey Epidemiology Follow-up Study cohort). The magnitudes of classical risk factors for CVD were examined in the steelworkers'cohort. This cohort included 5137 male steelworkers aged 18 years or more which recruited from 1974 to 1980 in Beijing Capital Steel and Iron Company, and followed up for an average of 20.84 years. We aimed to explore the relationship between PHHT and incidence of CVD in another cohort. The nationally representative cohort was conducted in 1991 and followed up during 1999-2000, including 169,871 adults≥40 years of age with an average of 8.3 years follow-up. All participants were divided into five groups according to PHHT status (no parent has hypertension, both parents have hypertension, only father has hypertension, only mother has hypertension and unknown). CVD was defined as diagnosis of acute myocardial infarction or stroke or death due to CVD (International Classification of Diseases, Ninth Revision:390.0-398.9,401.0-429.9 and 430.0-438.9). We used Cox proportional-hazards regression model to evaluate the risk of developing a first CVD event in the study participants who were free of CVD at the baseline.The findings of the long term prospective study have confirmed that classical risk factors suck as hypertension, cigarette smoking, BMI and TC were major independent determinants and predictors of CVD events in Chinese males. The hazard ratio (HR) associated with every 20 mmHg rise in systolic blood pressure (SBP) was 1.63 in this Chinese male population, which was higher than in Caucasians. Compared to non-smokers, men who smoked not less than one-pack-a-day had a HR of 2.43 (95% confidence interval [CI],1.75-3.38). Multivariable-adjusted HRs for CVD were 1.13 (95% CI,1.04-1.23) for every 20mg/dl increase in total serum cholesterol (TC) and 1.06 (95%CI,1.02-1.09) for every point rise of body mass index (BMI), respectively. The population-attributable risk (PAR) for hypertension, smoking, overweight (BMI≥24kg/m2) and hypercholesterolemia were 29.2%,29.4%,7.7% and 4.8%, respectively. Continued strengthening programs for prevention and intervention on those risk factors are needed to reduce incidence of CVD in China.It's also found that 12,412 participants reported positive PHHT(11.3%). Higher BMI and blood pressure were observed in the positive PHHT than in the negative PHHT participants. Individuals with positive PHHT were more likely physically inactive. A positive parental history had a 30 percent higher risk of CVD in the total cohort. After adjustment for age, systolic blood pressures, body mass index, physical activity, cigarette smoking, alcohol consumption status, geographic variation (north or south), urbanization (urban vs. rural) and education, compared with negative PHHT, the HRs (95% CI) for both parental history of hypertension, paternal history of hypertension, maternal history of hypertension, were 1.32 (1.03-1.70),1.19 (0.96-1.39),1.32 (1.13-1.54) in men and 1.42 (1.05-1.91),1.20 (0.96-1.49),1.25 (1.05-1.48) in women, respectively. Our prospective data demonstrated that PHHT was positively associated with CVD, and PHHT might be an independent predictor for CVD.