Large-scale population phenotyping for molecular epidemiological studies is subject to all the usual criteria of analytical chemistry. As part of a major phenotyping investigation we have used high-resolution 1H NMR spectroscopy to characterize 24-h urine specimens obtained from population samples in Aito Town, Japan (n = 259), Chicago, IL (n = 315), and Guangxi, China (n = 278). We have investigated analytical reproducibility, urine specimen storage procedures, interinstrument variability, and split specimen detection. Our data show that the multivariate analytical reproducibility of the NMR screening platform was >98% and that most classification errors were due to urine specimen handling inhomogeneity. Differences in metabolite profiles were then assessed for Aito Town, Chicago, and Guangxi population samples; novel combinations of biomarkers were detected that separated the population samples. These cross-population differences in urinary metabolites could be related to genetic, dietary, and gut microbial factors.

Vegetable protein intake was inversely related to blood pressure. This finding is consistent with recommendations that a diet high in vegetable products be part of healthy lifestyle for prevention of high blood pressure and related diseases.

For prevention of obesity in the 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 under the support of the International Life Sciences Institute Focal Point in China organized a meta-analysis on the relationship between BMI, waist circumference and risk factors of related chronic diseases (e.g., high diabetes, diabetes mellitus, and lipoprotein disorders). Thirteen population studies in all met the criteria for enrolment, with data of 239 972 adults (20-70 years of age) 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 were located in 21 provinces, municipalities and autonomous regions in mainland China as well as in Taiwan. Each enrolled study 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 the statistical analysis. The prevalence of hypertension, diabetes, dyslipidemia and clustering of risk factors all increased with increasing levels of BMI or waist circumference. A BMI of 24 with best sensitivity and specificity for identification of the risk factors was recommended as the cut-off point for overweight; a BMI of 28, which may identify the risk factors with specificity around 90%, was recommended as the cut-off point for obesity. A waist circumference over 85 cm for men and over 80 cm for women were recommended as the cut-off points for central obesity. Analysis of a population-attributable risk percentage illustrated that reducing the BMI to the normal range (<24) could prevent 45-50% of the clustering of risk factors. Treatment of obese persons (BMI = 28) with drugs could prevent 15-17% of clustering of risk factors. When waist circumference is controlled at under 85 cm for men and under 80 cm for women, it could prevent 47-58% of clustering of risk factors. Based on these guidelines, a classification of overweight and obesity for Chinese adults is recommended.

Background and Purpose-The goal of this article is to clarify the proportion of stroke subtypes in China, where stoke is the most common cause of death. Methods-A total of 16 031 first-ever strokes in subjects Ն25 years of age were identified in 1991 to 2000 from 17 Chinese populations through a community-based cardiovascular disease surveillance program in the China Multicenter Collaborative Study of Cardiovascular Epidemiology. World Health Organization diagnosis criteria were used for classification of stroke subtypes. Results-CT scan rate of stroke cases reached a satisfactorily high level only after 1996 in the study populations. In 8268 first-ever stroke events from 10 populations with CT scan rate Ͼ75% in 1996 to 2000, 1.8% were subarachnoid hemorrhage, 27.5% were intracerebral hemorrhage, 62.4% were cerebral infarction, and 8.3% were undetermined stroke. The proportion of intracerebral hemorrhage varied from 17.1% to 39.4% and that for cerebral infarction varied from 45.5% to 75.9% from population to population. The ratio of ischemic to hemorrhagic stroke ranged from 1.1 to 3.9 and averaged 2.0). The 28-day fatality rate was 33.3% for subarachnoid hemorrhage, 49.4% for intracerebral hemorrhage, 16.9% for cerebral infarction, and 64.6% for undetermined stroke. Conclusions-In our study, ischemic stroke was more frequent and its proportion was higher than hemorrhagic stroke in Chinese populations. Although hemorrhagic stroke was more frequent in Chinese than in Western populations, the variation in the proportion of stroke subtypes among Chinese populations could be as large as or larger than that between