[A discussion on utility and purposed value of obesity and abdomen obesity when body mass index, waist circumference, waist to hip ratio used as indexes predicting hypertension and hyper-blood glucose]

Abstract

Objective: Discussion on utility and purposed value of obesity and abdomen obesity when body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) used as indexes predicting hypertension, hyper-blood glucose, and both clusters, to provide scientific basis for the decision on the indexes and their cut-off points of obesity and abdomen obesity in Chinese people.

Methods: Using the data of diabetes mellitus (DM) from epidemiological studies carried out in 11 provinces/autonomous regions/municipalities of China from July 1995 to June 1997. Partial relative analysis, logistic multi-factors regression analysis, interaction analysis were used. Relative risk (RR), attributable risk proportion (ARP) and population attributable risk proportion (PARP) of hypertension, hyper-blood glucose, and the both cluster as BMI, WC, WHR with the different cut off points were analysed.

Results: 1) The correlations between BMI, WC and blood pressure, blood glucose were better than the WHR. 2) After adjusted by age, sex, occupation leisure physical activity, education degree and the family history of DM, the results suggested that BMI, WC, WHR were important predictive factors, with relative importance as BMI > WC > WHR. 3) There were augment interactions on BMI, WC and WHR with hypertension, hyper-blood glucose, with the interaction of BMI and WC in particular. Their pure attributable interaction proportion were from 5.95% to 29.34%. 4) The values of RR were about 2.5 when BMI >/= 23, >/= 24 and >/= 25, suggesting the relationship with exposure factors and diseases were with medium and high maleficent extent. Their ARP were from 0.580 to 0.623 with PARP from 0.259 to 0.425. The values of RR were from 2.06 to 3.08 as WC >/= 85 cm in males, WC >/= 80 cm in females while WC >/= 90 cm in males, WC >/= 80 cm in females, which suggested that the relationship with exposure factors and diseases were in medium and high maleficent extent. Their ARP were from 0.515 to 0.676 while PARP from 0.241 to 0.431.

Conclusions: Since the maleficent extent of exposure factors to diseases, the acceptability for overweight and obesity in population, and the prevention and care for overweight and obesity were just in the introduction stage in China. The utility value of predicted hypertension, hyper-blood glucose in BMI and WC seemed to be better then in WHR. We suggested that BMI used as the obesity index, with the diagnostic cut-off point BMI >/= 24. WC as the abdomen obesity index. The diagnostic cut-off points are suggested to be WC >/= 85 cm in males, and WC >/= 80 cm in females.