Yihe Li

Estimation of 10-Year Risk of Fatal and Nonfatal Ischemic Cardiovascular Diseases in Chinese Adults

Background— Stroke is much more prevalent than coronary heart disease in China; thus, any risk prediction model only for coronary heart disease may not be appropriate in application. Our objective is to develop a cardiovascular risk prediction model appropriate for the Chinese population. Methods and Results— Cox proportional hazards regression was used to develop sex-specific optimal 10-year risk prediction models for ischemic cardiovascular disease (ICVD; including ischemic stroke and coronary events) from 17 years of follow-up data from the USA-PRC Collaborative Study of Cardiovascular Epidemiology cohort, in which 9903 participants were followed up every 2 years until 2000, and 371 ICVD events (266 strokes and 105 coronary heart disease events) occurred. The models showed ICVD was positively related to age, systolic blood pressure, serum total cholesterol, body mass index, current smoking status, and diabetes mellitus in both men and women. When the models were applied to the 17 329 participants in the China Multicenter Collaborative Study of Cardiovascular Epidemiology cohort, the areas under the receiver operating characteristic curve were 0.796±0.036 for men and 0.791±0.036 for women. The simplified point score model resulted in similar c statistics. Comparison of the observed with the estimated incidence of ICVD at different risk levels showed satisfactory precision. Meanwhile, application of recalibrated Framingham models significantly overestimated the coronary heart disease risk in both men (by ≈97%) and women (by ≈228%). Conclusions— The Cox regression prediction models and simplified point score model have satisfying predictive capability for estimating the 10-year integrated cardiovascular risk in Chinese, in whom stroke is the predominant cardiovascular disease.

Body mass, fat distribution and cardiovascular risk factors in a lean population of South China

The associations of body mass index and abdominal adiposity, represented by an elevated waist/hip circumference ratio, with cardiovascular risk factors were examined in men and women, aged 28-69 years, from urban and rural areas of Guangzhou, China. Mean body mass index ranged from 20.1 to 21.9 kg/m2 across the four sex- and area-groups. Mean waist/hip ratio was 0.84 in men and 0.80 in women. After accounting for age and body mass index, waist/hip ratio was associated negatively (p < 0.05) with fasting serum HDL cholesterol (both sexes), and positively with serum triglycerides (both sexes), total and LDL cholesterol (men only), uric acid (both sexes), glucose (women only), and mean systolic blood pressure (women only). Body mass index was associated in a similar direction with most of these risk factors. These data confirm that abdominal adiposity is independently associated with cardiovascular disease risk factors, even in a lean Asian population.

A north-south comparison of blood pressure and factors related to blood pressure in the People's Republic of China : a report from the PRC-USA collaborative study of cardiovascular epidemiology

Objectives: To compare blood pressures in northern (Beijing) and southern (Guangzhou) Chinese population samples aged 35–54 years, males and females, urban and rural, and to assess the role of blood pressure-related traits in explaining north-south differences. Design Cross-sectional surveys were conducted in 1983–1984 of northern and southern populations employed in industry (urban) or farming (rural). Methods: In the north samples were selected from the Capital Iron and Steel Complex (urban) and Shijingshan district (rural); in the south samples from the Guangzhou Shipyard (urban) and Panyu County (rural) were used. Results: The number of subjects surveyed in north and south were 4706 and 4179, respectively: 1500 and 1052 urban males, and 717 and 914 rural males; and 1300 and 1061 urban females, and 1189 and 1152 rural females, respectively. Average systolic (SBP) and diastolic (DBP) blood pressures, were consistently higher in the north than in the south. SBP and DBP were significantly and independently related to age, body mass index, heart rate, use of antihypertensive drugs, serum triglycerides level, alcohol use (males only) and inversely to cigarette smoking. Northerners were older, taller, heavier and had higher body mass index and triglycerides level than southerners. With adjustment of SBP and DBP for blood pressure-related traits, north-south blood pressure differences decreased, but remained significant for urban males, rural males and rural females, with sizeable differences for rural samples in particular. Conclusions: North-south differences in blood pressure in these samples are accounted for only partly by north-south differences in the cited blood pressure-related traits. The role of other traits requires assessment.

Changes in average blood pressure and incidence of high blood pressure 1983-1984 to 1987-1988 in four population cohorts in the People's Republic of China

Objective To assess comparative changes in systolic and diastolic blood pressure and incidence of high blood pressure over 4 years, and factors related to these changes, in northern and southern, urban and rural adults in the Peoples Republic of China. Setting This is a prospective study of populations surveyed by standardized methods in 1983-1984 and 1987-1988 in north China, Beijing area steel mill workers and farmers, and south China, Guangzhou area shipyard workers and farmers. Subjects The subjects were 8805 men and women aged 35-54 years at baseline (1983-1984), of whom 7338 were non-hypertensive (systolic blood pressure <140, diastolic blood pressure <90mmHg, not being administered antihypertensive drugs). Main outcome measures The main outcome measures were 4-year changes in systolic and diastolic blood pressures and the 4-year incidence of high blood pressure in persons not hypertensive at baseline. Results At baseline, the average systolic and diastolic blood pressures were higher for Beijing than for Guangzhou cohorts. At resurvey the average systolic blood pressure had increased for seven of eight sex-city-setting cohorts (all but Guangzhou urban men). The Beijing urban cohorts had the greatest increases (men 6.2 mmHg, women 4.9 mmHg, slopes of 1.6 and 1.2 mmHg/year). The incidence of high blood pressure was higher for Beijing than for Guangzhou cohorts in all four comparisons (men and women, urban and rural). Beijing men, urban and rural, had the highest incidence rates (about 21%). In multiple logistic analyses by sex, variables significantly related to 4-year high blood pressure incidence were city, baseline systolic blood pressure and body mass index, change in weight, and, for men, baseline alcohol use and heart rate. Conclusion Modifiable lifestyle traits, previously shown to be related to blood pressure and high blood pressure in cross-sectional studies, also relate to the incidence of hypertension.

Relation of Occupational Change to Cardiovascular Risk Factor Levels in Rural Chinese Men: The People’s Republic of China–United States Collaborative Study on Cardiovascular and Cardiopulmonary Epidemiology

During the second half of the 20th century, millions of people in developing countries ceased to be farmers and sought other occupations. Little has been reported of the impact of this transition on risk factors for cardiovascular disease (CVD) and other chronic diseases. Ecological and prospective studies indicate that elevated blood pressure, elevated total cholesterol (TC), obesity, and smoking are major risk factors for stroke and coronary heart disease (CHD) in Chinese populations.1–4 Concurrent with economic development in China, levels of risk factors have tended to rise.5 This study examined men residing in rural areas near big cities who worked as farmers in 1983–1984 and the relation of occupational change from 1983–1984 to 1993–1994 and their CVD risk factor changes.