Epidemiological characteristics of obesity and its relation to chronic diseases among middle aged and elderly men

Abstract

To investigate the epidemiological characteristics of obesity and how they related to chronic diseases among middle aged and elderly men in urban Shanghai. A cross-sectional analysis was conducted using data from a baseline survey from an on-going cohort study of 61 500 men between 40 - 74 of age in urban Shanghai. Study subjects were recruited from 8 communities of an urban district in Shanghai during 2002 to 2006. General obesity was measured by body mass index (BMI >/= 28) and, central obesity by waist to hip ratio (WHR >/= 0.9). Unconditional logistic regression model was used to estimate the odds ratio and 95% confidence interval of chronic diseases associated with obesity after adjustment for potential confounding factors. The aged-adjusted prevalence rates of overweight, overall obesity and central obesity were 36.8%, 7.7% and 49.7% respectively. In this population, 66.7% subjects had ever been diagnosed with one or more kinds of chronic diseases, in which hypertension ranked first with an age-adjusted prevalence rate of 26.5%. After mutual adjustment for WHR and BMI, obesity (BMI >/= 28) appeared to be associated with increased prevalence rates of hypertension, coronary heart disease, gallstone, urinary tract calculus and stroke comparing to men having normal BMI (18.5 < / = BMI < 24) with ORs ranged from 1.16 to 3.13. However, to the lowest quartile, the ORs associated with the highest WHR were between 1.20 and 1.69 for these 5 diseases. All P values for trend tests were less than 0.05. WHR was positively associated with diabetes, with OR as 2.40 (95%CI: 2.14 - 2.70) for the highest quartile comparing to the lowest quartile. BMI was unrelated to the diabetes prevalence. Prevalence of chronic obstructive pulmonary disease decreased with increasing BMI, but increased with WHR. The corresponding OR was 0.87 (95%CI: 0.77 - 0.98) for the obese men compared to those with normal BMI while 1.26 (95%CI: 1.14 - 1.40) for the subjects with the highest WHR comparing to those with the lowest WHR. The prevalence rates of hypertension, gallstone, urinary tract calculus, cardiovascular and cerebrovascular diseases were higher in obesity men. Central obesity seemed to be related to high prevalence of diabetes.