Xiufang Duan

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.

Prevalence of Cardiovascular Disease Risk Factor Clustering Among the Adult Population of China Results From the International Collaborative Study of Cardiovascular Disease in Asia (InterAsia)

Background—The prevalence of cardiovascular disease (CVD) risk factors has been increasing in China. Methods and Results—We examined the prevalence of CVD risk factor clustering among Chinese adults aged 35 to 74 years with data from the International Collaborative Study of Cardiovascular Disease in Asia (InterAsia), a cross-sectional survey of a nationally representative sample (n=14 690) conducted during 2000 to 2001 and compared these data with those of US adults from the National Health and Nutrition Examination Survey of 1999 to 2000. Overall, 80.5%, 45.9%, and 17.2% of Chinese adults had ≥1, ≥2, and ≥3 modifiable CVD risk factors (dyslipidemia, hypertension, diabetes, cigarette smoking, and overweight), respectively. By comparison, 93.1%, 73.0%, and 35.9% of US adults had ≥1, ≥2, and ≥3 of these risk factors, respectively. In a multivariate model including age, sex, and area of residence, the odds ratio (95% confidence interval [CI]) of having ≥1, ≥2, and ≥3 CVD risk factors versus none of the studied risk factors was 2.61 (95% CI, 2.09 to 3.27), 3.55 (95% CI, 2.77 to 4.54), and 4.97 (95% CI, 3.67 to 6.74), respectively, for Chinese adults 65 to 74 years old versus 35 to 44 years old; 3.65 (95% CI, 3.21 to 4.15), 4.67 (95% CI, 4.06 to 5.38), and 5.60 (95% CI, 4.70 to 6.67), respectively, for men compared with women; 1.18 (95% CI, 1.07 to 1.30), 1.34 (95% CI, 1.21 to 1.50), and 1.84 (95% CI, 1.60 to 2.12), respectively, for urban compared with rural residents; and 1.98 (95% CI, 1.76 to 2.22), 2.75 (95% CI, 2.42 to 3.13), and 4.36 (95% CI, 3.68 to 5.18), respectively, for residents of northern compared with southern China. Conclusions—Clustering of CVD risk factors is common in China. Prevention, detection, and treatment of CVD risk factor clustering should be an important component of a national strategy to reduce the increasing burden of CVD in 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.

Gender Difference in Blood Pressure Responses to Dietary Sodium Intervention in the GenSalt Study

Objective To examine factors related to blood pressure (BP) responses to dietary sodium and potassium interventions. Methods We conducted a dietary feeding study that included a 7-day low-salt intervention (51.3 mmol sodium/day), a 7-day high-salt intervention (307.8 mmol sodium/day), and a 7-day high-salt and potassium-supplementation (60 mmol potassium/day) intervention among 1906 study participants in rural China. The BP was measured nine times during the 3-day baseline observation and during the last 3 days of each intervention phase using a random-zero sphygmomanometer. Results The BP responses to low-sodium intervention were significantly greater in women than in men: −8.1 [95% confidence interval (−8.6 to −7.6)] versus −7.0 (−7.5 to −6.6) mmHg for systolic and −4.5 (−4.9 to −4.1) versus −3.4 (−3.8 to −3.0) mmHg for diastolic. Likewise, BP responses to high-sodium interventions were significantly greater in women than in men: 6.4 (5.9–6.8) versus 5.2 (4.8–5.7) mmHg for systolic and 3.1 (2.7–3.5) versus 1.7 (1.4–2.1) mmHg for diastolic (all P < 0.001). In addition, systolic BP responses to sodium interventions increased with age, and both systolic and diastolic BP responses to sodium interventions increased with baseline BP levels. BP responses to potassium supplementation also increased with baseline BP levels. Conclusion These results suggest that female gender, older age, and hypertension increase the sensitivity to dietary sodium intervention. Furthermore, low dietary sodium intake may be more effective in reducing BP among these subgroups.

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.

Factors Associated With Hypertension Awareness, Treatment, and Control in a Representative Sample of the Chinese Population

Abstract—We studied factors associated with awareness, treatment, and control of hypertension (systolic/diastolic blood pressure measurements ≥140/90 mm Hg, respectively, and/or current drug treatment for hypertension) in a representative sample of the Chinese population (n=15 838). Awareness, treatment, and control were defined by self-report of a hypertension diagnosis, self-report of current antihypertensive medication use, and a systolic and diastolic blood pressure <140/90 mm Hg, respectively. Higher awareness (OR; 95% CI) was noted for persons who were married (1.43; 1.09, 1.88) and had their blood pressure measured in 1 year (47.4; 31.7, 70.4) or 1 to 5 years (11.4; 7.09, 18.2) preceding their study visit; lower awareness was found among men (0.62; 0.52, 0.74) and current smokers (0.79; 0.63, 0.99). Among those aware of their hypertension, treatment was more common (OR; 95% CI) at higher income (1.24 [0.87, 1.75], 1.46 [1.01, 2.12] and 1.58 [1.06, 2.37] for increasing versus the lowest quartile of income) and for participants who had their blood pressure measured during the preceding year (3.87; 1.89, 7.93) and was less common among men (0.76; 0.59, 0.98). Controlled hypertension was more common (OR; 95% CI) among persons whose blood pressure had been measured 1 year (4.93; 1.51, 16.1) and 1 to 5 years (14.8; 3.63, 60.5) prior to their study visit and, among persons aware of their hypertension diagnosis, those who undertook lifestyle modification (1.59; 1.11, 2.27). These data identify potential methods for improving blood pressure control in China through the identification, follow-up, and lifestyle modification of persons with high blood pressure.

Body Mass Index and Risk of Stroke among Chinese Men and Women

The relationship between body mass index (BMI) and stroke incidence and mortality remains controversial, particularly in Asian populations.