| Concurrence of multiple metabolic disturbances, including obesity, hyperinsulinemia, hyperglycemia, hypertension, hypertriglyceridemia and low HDL-cholesterol, has been referred to as the metabolic syndrome. The syndrome has been established as a strong risk factor for type 2 diabetes and cardiovascular disease. In this dissertation we assessed the prevalence and the characteristics of the metabolic syndrome in a representative sample of 529 rural and urban adults aged 20--64 yr in east China.; In the first study, we used confirmatory maximum likelihood factor analysis to assess the clustering pattern among the constituents of the metabolic syndrome. We hypothesized that obesity, dyslipidemia, insulin resistance and hypertension, as four major related features of the syndrome, were united by a single underlying pathophysiologic process.; In the second study, we assessed the relationship of body mass index (BMI, in kg/m2) with the risk of obesity-related metabolic disorders and identified the BMI cutoffs which best predicted the risk. We observed a significant dose-response relationship between BMI and the odds of obesity-related metabolic disorders.; In the third study, we examined the urban-rural differences in the prevalence of the metabolic syndrome. Urban dwelling was associated with increased dietary fat intake and significant less occupational physical activity level. According to the waist circumference cutoff (108 cm for men, 88 cm for women) in the National Cholesterol Education Program Adult Treatment Panel III guideline (ATP III), the prevalence of central obesity was quite low in our subjects.; In conclusion, metabolic syndrome, as a unified entity, can be predicted well by BMI or waist circumference. For the Chinese population, BMI at 23 might be an appropriate cutoff for identifying the syndrome, and Asian waist circumference cutoff classified metabolic disorders more accurately than that in the ATP III. At the current stage of nutrition transition in China, urban residents had lower occupational physical activity and higher risk of metabolic disorders than their rural counterparts. The impact of urbanization on the metabolic syndrome was more evident in men than in women. (Abstract shortened by UMI.)... |
