Prevalence of overweight and obesity in Chinese middle-aged populations: Current status and trend of development / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the current status on prevalence of overweight and obesity in Chinese middle-aged population, and to quantify the magnitude of the trends of development in the past two decades.</p><p><b>METHODS</b>Body mass index (BMI) was measured on 15 389 middle-aged men and women from 15 natural populations all over China with different geographical, economical (urban/rural) and occupational status. Overweight was defined as BMI >/= 25 while obesity as BMI >/= 30.</p><p><b>RESULTS</b>1) The rates of prevalence on overweight and obesity varied dramatically between populations. 2) In general, the prevalence rates were higher in the northern areas, in urban areas, and in women. 3) The current problem of obesity was related to 'pre-obese' stage, with less than 10% in most populations. 4) The prevalence of overweight and obesity started to show significantly increase from early 80's to early 90's but more prominant in the late 90's.</p><p><b>CONCLUSION</b>Prevention and intervention of overweight and obesity are in urgent need in the Chinese populations, especially in those economically fast developing areas.</p>

A prospective study on body mass index and mortality / 中华流行病学杂志

<p><b>OBJECTIVE</b>To assess the relationship between body mass index (BMI, weight in kilograms divided by the square of height in meters) and both all-causes mortality and mortality from specific cause.</p><p><b>METHODS</b>Cardiovascular disease (CVD) risk factors were studied in 1982 - 1985 on more than 30 thousands participants aged 35 - 59 from 10 Chinese populations. 30 560 participants (15 723 for men, 148 837 for women) without known myocardial infraction, stroke or cancer was followed from 1999 to 2000. All-causes of death were documented.</p><p><b>RESULTS</b>Three thousand two hundred and twelve death cases occurred during follow-up of average 15.2 years, including 676 CVD (coronary heart disease and stroke) deaths, 1 281 cancer deaths and 1 255 deaths for other reasons. Cox proportional hazards model adjusting age and gender showed that the relative risks of all causes of death in groups of low BMI (BMI < 18.5), normal BMI (BMI from 18.5 to 23.9), overweight (BMI from 24 to 27.9) and obesity (BMI >/= 28) which were defined according to the strata of BMI for Chinese were 1.21 (95% CI: 1.10 - 1.33), 1.00, 0.91 (95% CI: 0.82 - 1.01) and 1.12 (95% CI: 0.93 - 1.37), respectively ("U" shaped relation). The relative risk of low BMI group (RR = 1.01, 95% CI: 0.84 - 1.21) was not significant different and the relative risk of obesity significantly increased (RR = 1.36, 95% CI: 1.04 - 1.80) while the lowest relative risk was in normal BMI group. The relative risks increased for CVD death, but decreased for cancer death with increased levels of BMI and a "U" shaped relationship was found between BMI groups and mortality for other reasons, which remained after excluding the early death and smokers.</p><p><b>CONCLUSION</b>BMI in normal level was not only related to low risk of all causes of death, but also with relative low risk of CVD, cancer and other deaths. Data were important to public health.</p>

Prospective study for cut-off points of body mass index in Chinese adults / 中华流行病学杂志

<p><b>OBJECTIVE</b>To verify the optimal cut-off point for overweight and obesity in Chinese adults based on the relationship of body mass index (BMI) to all-cause mortality and incidence of coronary heart disease (CHD) and stroke from pooled data of Chinese cohorts.</p><p><b>METHODS</b>Pooling the data of four Chinese cohorts, to analyze the age-adjusted all-cause mortality by strata of BMI, and to repeat the analyses after excluding deaths within the first three years of follow-up and after excluding the smokers. Analyzing the age-adjusted incidence of CHD and stroke by strata of BMI. Pooling the Cox regression coefficients of BMI to incidence of CHD or stroke of different cohorts using the method of weighting by inverse of variance.</p><p><b>RESULTS</b>All together 76,227 people from 4 cohorts were enrolled, with 745,346 person-year of follow-up. All-cause mortality by strata of BMI showed a U shaped curve, even after excluding deaths from the first three years and the smokers. Age-adjusted all-cause mortality increased when BMI was lower than 18.5 and higher than 28. Incidence rates of CHD and stroke increased when the level of BMI was increasing. Results of Cox regression showed that BMI was an independent risk factor for both CHD and stroke. Each amount of 2 kg/m(2) increase in baseline BMI might cause 15.4%, 6.1% and 18.8% in incidence of CHD, stroke and ischaemic stroke. Reduction of increased BMI to the level of under 24 might prevent incidence of CHD by 11% and that of stroke by 15% for men and 22% CHD and stroke for women in the population.</p><p><b>CONCLUSION</b>Attempt to define the levels of BMI < 18.5 for underweight, 24 to 27.9 for overweight and > or = 28 for obesity seemed to be appropriate cut-off points for Chinese adults.</p>

Predictive values of body mass index and waist circumference to risk factors of related diseases in Chinese adult population / 中华流行病学杂志

<p><b>OBJECTIVE</b>For prevention of obesity in Chinese population, it is necessary to define the optimal range of healthy weight and the appropriate cut-off points of body mass index (BMI) and waist circumference for Chinese adults. The Working Group on Obesity in China (WGOC) under the support of International Life Sciences Institute Focal point in China organized a meta-analysis on the relation between BMI, waist circumference and risk factors of related chronic diseases.</p><p><b>METHODS</b>All together 13 population studies met the criteria for enrollment, with data of 239 972 adults (20 - 70 year) surveyed in the 1990s. Data on waist circumference was available for 111 411 persons and data on serum lipids and glucose were available for more than 80 000. The study populations located in 21 provinces, municipalities and autonomous regions in mainland China as well as in Taiwan. Each enrolled study group provided data according to a common protocol and uniform format. The center for data management in the Department of Epidemiology, Fu Wai Hospital was responsible for statistical analysis.</p><p><b>RESULTS</b>The prevalence of hypertension, diabetes, dyslipidemia and clustering of risk factors all increased with increasing levels of BMI or waist circumference. BMI at 24 with best sensitivity and specificity for identification of the risk factors, was recommended as the cut-off point for overweight since and BMI at 28 which might identify the risk factors with specificity around 90% to be recommended as the cut-off point for obesity. Waist circumference beyond 85 cm for men and beyond 80 cm for women were recommended as the cut-off points for central obesity.</p><p><b>CONCLUSIONS</b>Analysis of population attributable risk percent illustrated that reducing BMI to normal range (< 24) could prevent 45% - 50% clustering of risk factors. Treatment of obese persons (BMI >/= 28) with drugs could prevent 15% - 17% clustering of risk factors. Control the waist circumference under 85 cm for men and under 80 cm for women, could prevent 47% - 58% clustering of risk factors.</p>

Serum TC/HDL-C ratio and the risk of ischemic and hemorrhagic stroke incidence in middle aged Chinese population / 中华神经科杂志

ObjectiveTo explore the predictive effect of serum TC/HDL-C ratio on ischemic and hemorrhagic stroke incidence in middle aged Chinese population.MethodsA prospective study was conducted based on the PRC-USA Collaborative Study on Cardiovascular and Cardiopulmonary Epidemiology. A total of 10 121 individuals (4921 men and 5200 women), aged 35—59 years were selected from 4 cohorts, in Beijing and Guangzhou, urban and rural. The average following up time was 15.9 years. During the follow-up period, 277 ischemic and 125 hemorrhagic stroke cases were diagnosed.ResultsThe age adjusted incidence rate of ischemic stroke was 144.1,169.4,166.7,226.9 and 282.2 in the group of TC/HDL-C ratio

THE RELATIONSHIPS OF DIETARY PROTEIN, SERUM AND URINE FREE AMINO ACIDS AND BLOOD PRESSURE IN THREE CHINESE POPULATIONS / 营养学报

The relationships of the quality and quantity of dietary protein, the level of fasting serum and 8-hour overnight urine free amino acids and blood pressure were studied in three natural Chinese populations. The results showed that the ratio of dietary animal protein/total dietary protein, the ratio of dietary protein/dietary sodium, serum and urine taurine, lysine etc were inversely associated with blood pressure significantly. Alanine was positively associated with blood pressure. Most serum free amino acids were positively correlated with the ratio of dietary protein/dietary sodium. Urine taurine, lysine and asparagine were positively correlated with dietary protein, dietary and urine sodium significantly. These results suggested that high quality protein which is rich in taurine, lysine etc might prevent hypertension.