Xigui Wu

Prevalence of the metabolic syndrome and overweight among adults in China.

BACKGROUND The metabolic syndrome and obesity are major risk factors for cardiovascular disease. Little information exists on the prevalence of the metabolic syndrome in China. We aimed to provide up-to-date estimates of the prevalence of the metabolic syndrome and overweight in the general adult population in China. METHODS We did a cross-sectional survey in a nationally representative sample of 15,540 Chinese adults aged 35-74 years in 2000-01. Metabolic syndrome was defined according to guidelines from the US National Cholesterol Education Program. Overweight was defined as body-mass index of 25.0 kg/m2 or greater. FINDINGS The age-standardised prevalence of metabolic syndrome was 9.8% (95% CI 9.0-10.6) in men and 17.8% (16.6-19.0) in women. The age-standardised prevalence of overweight was 26.9% (25.7-28.1) in men and 31.1% (29.7-32.5) in women. The prevalence of the metabolic syndrome and overweight was higher in northern than in southern China, and higher in urban than rural residents. INTERPRETATION Our results indicate that a large proportion of Chinese adults have the metabolic syndrome and that overweight has become an important public health problem in China. These findings emphasise the urgent need to develop national strategies for the prevention, detection, and treatment of overweight and the metabolic syndrome, to reduce the societal burden of cardiovascular disease in China.

Prevalence, Awareness, Treatment, and Control of Hypertension in China

Abstract—The objective of this study was to estimate the prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the general adult population in China. The International Collaborative Study of Cardiovascular Disease in ASIA (InterASIA), conducted in 2000–2001, used a multistage cluster sampling method to select a nationally representative sample. A total of 15 540 adults, age 35 to 74 years, were examined. Three blood pressure measurements were obtained by trained observers by use of a standardized mercury sphygmomanometer after a 5-minute sitting rest. Information on history of hypertension and use of antihypertensive medications was obtained by use of a standard questionnaire. Hypertension was defined as a mean systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, and/or use of antihypertensive medications. Overall, 27.2% of the Chinese adult population age 35 to 74 years, representing 129 824 000 persons, had hypertension. The age-specific prevalence of hypertension was 17.4%, 28.2%, 40.7%, and 47.3% in men and 10.7%, 26.8%, 38.9%, and 50.2% in women age 35 to 44 years, 45 to 54 years, 55 to 64 years, and 65 to 74 years, respectively. Among hypertensive patients, only 44.7% were aware of their high blood pressure, 28.2% were taking antihypertensive medication, and 8.1% achieved blood pressure control (<140/90 mm Hg). Our results indicate that hypertension is highly prevalent in China. The percentages of those with hypertension who are aware, treated, and controlled are unacceptably low. These results underscore the urgent need to develop national strategies to improve prevention, detection, and treatment of hypertension in China.

Mortality Attributable to Smoking in China

BACKGROUND Smoking is a risk factor for many diseases and has been increasingly prevalent in economically developing regions of the world. We aimed to estimate the number of deaths attributable to smoking in China. METHODS We conducted a large, prospective cohort study in a nationally representative sample of 169,871 Chinese adults who were 40 years of age or older. Investigators for the China National Hypertension Survey collected data on smoking and other risk factors at a baseline examination in 1991 using a standard protocol. Follow-up evaluation was conducted in 1999 and 2000, with a response rate of 93.4%. We used multivariable-adjusted relative risk, prevalence of smoking, mortality, and population size in each age group, stratified according to sex, to calculate the number of deaths attributable to smoking in 2005. RESULTS There was a significant, dose-response association between pack-years smoked and death from any cause in both men and women after adjustment for multiple risk factors (P<0.001 for trend). We estimated that in 2005, a total of 673,000 deaths (95% confidence interval [CI], 564,700 to 781,400) were attributable to smoking in China: 538,200 (95% CI, 455,800 to 620,600) among men and 134,800 (95% CI, 108,900 to 160,800) among women. The leading causes of smoking-related deaths were as follows: cancer, 268,200 (95% CI, 214,500 to 321,900); cardiovascular disease, 146,200 (95% CI, 79,200 to 213,100); and respiratory disease, 66,800 (95% CI, 20,300 to 113,300). CONCLUSIONS Our study documents that smoking is a major risk factor for mortality in China. Continued strengthening of national programs and initiatives for smoking prevention and cessation is needed to reduce smoking-related deaths in China.

Serum Total and Lipoprotein Cholesterol Levels and Awareness, Treatment, and Control of Hypercholesterolemia in China

Background—Cardiovascular disease has become the leading cause of death in China. We examined the levels of serum total and lipoprotein cholesterol and status of awareness, treatment, and control of hypercholesterolemia in China. Methods and Results—A cross-sectional survey in a nationally representative sample of 15 540 Chinese adults 35 to 74 years of age was conducted during 2000 to 2001. Serum cholesterol was measured by use of standard methods, and information on treatment of hyperlipidemia was obtained by use of a standard questionnaire. Age-standardized mean levels of total, HDL, and LDL cholesterol and triglycerides were 186.1, 51.7, 109.5, and 128.1 mg/dL, respectively. Of the Chinese population 35 to 74 years of age, 23.8% (112 500 000 persons) had borderline high total cholesterol (200 to 239 mg/dL), and 9.0% (42 540 000 persons) had high total cholesterol (≥240 mg/dL). The population estimates for borderline high (130 to 159 mg/dL), high (160 to 189 mg/dL), and very high (≥190 mg/dL) LDL cholesterol were 17.0% (80 122 000 persons), 5.1% (24 329 000 persons), and 2.7% (12 822 000 persons), respectively. In addition, 19.2%, or 90 803 000 persons, had a low HDL cholesterol (<40 mg/dL). Among those who had a total cholesterol ≥200 mg/dL or who were on cholesterol-lowering medications, the proportion of men and women who were aware, treated, and controlled was only 8.8% and 7.5%, 3.5% and 3.4%, and 1.9% and 1.5%, respectively. Conclusions—The prevalence of hypercholesterolemia was relatively high and the percentage of adults with controlled blood cholesterol was low in China. Prevention and treatment of hypercholesterolemia should be an important component of a national strategy to reduce the substantial and increasing burden of cardiovascular disease in China.

Premature deaths attributable to blood pressure in China: a prospective cohort study

BACKGROUND Hypertension is a major global-health challenge because of its high prevalence and concomitant risks of cardiovascular disease. We estimated premature deaths attributable to increased blood pressure in China. METHODS We did a prospective cohort study in a nationally representative sample of 169,871 Chinese adults aged 40 years and older. Blood pressure and other risk factors were measured at a baseline examination in 1991 and follow-up assessment was done in 1999-2000. Premature death was defined as mortality before age 72 years in men and 75 years in women, which were the average life expectancies in China in 2005. We calculated the numbers of total and premature deaths attributable to blood pressure using population-attributable risk, mortality, and the population size of China in 2005. FINDINGS Hypertension and prehypertension were significantly associated with increased all-cause and cardiovascular mortality (p<0.0001). We estimated that in 2005, 2.33 million (95% CI 2.21-2.45) cardiovascular deaths were attributable to increased blood pressure in China: 2.11 million (2.03-2.20) in adults with hypertension and 0.22 million (0.19-0.25) in adults with prehypertension. Additionally, 1.27 million (1.18-1.36) premature cardiovascular deaths were attributable to raised blood pressure in China: 1.15 million (1.08-1.22) in adults with hypertension and 0.12 million (0.10-0.14) in adults with prehypertension. Most blood pressure-related deaths were caused by cerebrovascular diseases: 1.86 million (1.76-1.96) total deaths and 1.08 million (1.00-1.15) premature deaths. INTERPRETATION Increased blood pressure is the leading preventable risk factor for premature mortality in the Chinese general population. Prevention and control of this condition should receive top public-health priority in China. FUNDING American Heart Association (USA); National Heart, Lung, and Blood Institute, National Institutes of Health (USA); Ministry of Health (China); and Ministry of Science and Technology (China).

Prevalence and Risk Factors of Overweight and Obesity in China

Objective: To examine the prevalence and risk factors of overweight and obesity in China.

Prevalence of hypertension and its trends in Chinese populations

The third nation-wide survey of blood pressure level and hypertension was carried out in China in 1991. In total, 950,356 residents aged > or = 15 years were examined. Sampling population were composed of half urban and half rural from 27 provinces or autonomous regions and three municipalities. The results showed that: (1) the age-adjusted prevalence rate of hypertension (systolic blood pressure > or = 140 mmHg or diastolic blood pressure > or = 90 mmHg) was 11.26% (male 12.15%, female 10.32%) and the definite hypertension rate (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or on medication) was 5.29% (male 5.38%, female 5.21%); rate of borderline hypertension was evaluated from 2.82% to 6.15% during the 10-year period from 1979/1980 to 1991; (2) the prevalence rate was progressively increased with age, especially after age 35; prevalence rates were generally higher in men than women before about age 44, however by age 60, women had a higher prevalence of hypertension; (3) a general trend of decrease in prevalence from north-eastern to south-western China was confirmed; (4) there were significantly lower rates in rural than in urban areas. Results of preliminary analysis for prevalence of hypertension among different occupations, nationalities, and educational levels were presented.

Cigarette Smoking and Exposure to Environmental Tobacco Smoke in China: The International Collaborative Study of Cardiovascular Disease in Asia

OBJECTIVES We estimated the prevalence of cigarette smoking and the extent of environmental tobacco smoke exposure (ETS) in the general population in China. METHODS A cross-sectional survey was conducted on a nationally representative sample of 15540 Chinese adults aged 35-74 years in 2000-2001. Information on cigarette smoking was obtained by trained interviewers using a standard questionnaire. RESULTS The prevalence of current cigarette smoking was much higher among men (60.2%) than among women (6.9%). Among nonsmokers, 12.1% of men and 51.3% of women reported exposure to ETS at home, and 26.7% of men and 26.2% of women reported exposure to ETS in their workplaces. On the basis of our findings, 147358000 Chinese men and 15895000 Chinese women aged 35-74 years were current cigarette smokers, 8658000 men and 108402000 women were exposed to ETS at home, and 19072000 men and 55372000 women were exposed to ETS in their workplaces. CONCLUSIONS The high prevalence of cigarette smoking and environmental tobacco smoke exposure in the Chinese population indicates an urgent need for smoking prevention and cessation efforts.

Cigarette Smoking and Risk of Stroke in the Chinese Adult Population

Background and Purpose— We studied the relationship between cigarette smoking and stroke incidence and mortality in the Chinese adult population. Methods— We conducted a prospective cohort study in a nationally representative sample of 169 871 Chinese men and women aged 40 years and older. Data on cigarette smoking and other covariables were collected at a baseline examination in 1991 using a standard protocol. Follow-up evaluation was conducted in 1999 to 2000, with a response rate of 93.4%. Results— During an average of 8.3 years follow-up, a total of 6780 stroke events (3979 fatal strokes) were observed. The multivariate-adjusted relative risks (95% confidence interval) of stroke incidence and mortality associated with present cigarette smoking were 1.28 (1.19 to 1.37) and 1.13 (1.03 to 1.25) in men and 1.25 (1.13 to 1.37) and 1.19 (1.04 to 1.36) in women, respectively. The corresponding population attributable risks were 14.2% and 7.1% in men and 3.1% and 2.4% in women. Compared to never-smokers, the multivariate-adjusted relative risks of stroke incidence (95% confidence interval) were 1.21 (1.12 to 1.31), 1.21 (1.11 to 1.32), and 1.36 (1.25 to 1.47) for those who smoked 1 to 9, 10 to 19, and ≥20 cigarettes per day; and 1.18 (1.09 to 1.28), 1.25 (1.15 to 1.35), and 1.34 (1.24 to 1.44) for those who smoked 1 to 11, 12 to 26, and >26 pack-years, respectively (both P<0.0001 for linear trends). Conclusions— Our study identified a positive and dose-response relationship between cigarette smoking and risk of stroke. Smoking prevention and cessation programs should be an important strategy for reducing the burden of stroke in Chinese adults.

Hypertension subtype and risk of cardiovascular disease in Chinese adults.

Background— We examined the relationship between hypertension subtype and cardiovascular disease incidence and mortality in Chinese adults. Methods and Results— We conducted a prospective cohort study in a nationally representative sample of 169 871 Chinese men and women aged ≥40 years. Data on systolic (SBP) and diastolic blood pressure (DBP) and other variables were obtained at a baseline examination in 1991 with the use of standard protocols. Follow-up evaluation was conducted in 1999–2000, with a response rate of 93.4%. Hypertension subtypes were defined as combined systolic and diastolic hypertension (SBP ≥140 and DBP ≥90 mm Hg), isolated systolic hypertension (SBP ≥140 and DBP <90 mm Hg), isolated diastolic hypertension (SBP <140 and DBP ≥90 mm Hg), and 2 categories of treated hypertension (SBP <140 and DBP <90 mm Hg or SBP ≥140 and/or DBP ≥90 mm Hg). After participants with missing BP values were excluded, 169 577 adults were included in the analyses. Compared with normotensives, relative risks (95% CIs) of cardiovascular disease incidence and mortality were 2.73 (2.60 to 2.86) and 2.53 (2.39 to 2.68) for combined systolic and diastolic hypertension, 1.78 (1.69 to 1.87) and 1.68 (1.58 to 1.78) for isolated systolic hypertension, 1.59 (1.43 to 1.76) and 1.45 (1.27 to 1.65) for isolated diastolic hypertension, 2.01 (1.64 to 2.48) and 1.61 (1.28 to 2.03) for treated hypertension with SBP <140 and DBP <90 mm Hg, and 3.37 (3.07 to 3.69) and 2.88 (2.60 to 3.19) for treated hypertension with SBP ≥140 and/or DBP ≥90 mm Hg, respectively, after adjustment for important covariables. Conclusions— Our results indicate that all hypertension subtypes are associated with significantly increased risk of cardiovascular disease in Chinese adults. Primary prevention of hypertension should be a public health priority in the Chinese population.