Body fat distribution and risk of diabetes among Chinese women

Abstract

OBJECTIVE: To assess the relationship between measures of central and overall obesity and risk of diabetes. DESIGN: Nested case-control study. SETTING: Shanghai, China. PARTICIPANTS: A total of 57 130 women were screened for diabetes at enrollment for the Shanghai Women's Health Study (SWHS), a population-based cohort study of Chinese women aged 40-70 y. In this study, 345 women diagnosed with diabetes and 2760 age-matched controls (eight controls per case), randomly selected from women who tested negative for urine glucose, were included. RESULTS: Risk of diabetes increased significantly with increasing levels of obesity, particularly with measures of central obesity. Compared to those in the lowest quartile, women in the highest quartile of body mass index (BMI) (Z26.57) and waist to hip ratio (WHR) (Z0.855) had a 2.57-fold (95% CI 1.75-3.77) and a 6.05-fold (95% CI 4.05-9.04) increased risk of diabetes, respectively. The risk of diabetes was elevated with increasing WHR at all levels of BMI, while the positive association between BMI and diabetes was observed primarily among women with a low WHR. However, test for multiplicative interaction was not statistically significant. CONCLUSIONS: Our data indicated that central obesity is a stronger risk factor for diabetes than overall obesity, suggesting that WHR may be a better indicator of risk of diabetes than BMI among Chinese women. IntroductionEstimates from the World Health Organization predict that by the year 2025, 300 million people worldwide will be diagnosed with diabetes. 1 The Asian/Pacific region, accounting for 46 percent of the global burden of diabetes, includes the largest population of people diagnosed with diabetes in the world. 2 Studies among the Chinese have demonstrated an increase in the prevalence of diabetes during the past 10 years, particularly in urban areas such as Shanghai. [3][4][5][6][7][8][9] The increased prevalence of type II diabetes in these and other Asian populations can be attributed, at least partially, to increases in obesity. 2,[5][6][7]10 Body mass index (BMI) and waist to hip ratio (WHR) are the two anthropometric measurements most frequently used to assess obesity and central obesity. Although epidemiological studies have demonstrated that both BMI and WHR are powerful predictors of type II diabetes, the relative contribution of each to an individual's risk remains unclear. [11][12][13][14][15][16][17][18][19] Further complicating this issue, quantitative definitions used to indicate obesity differ among studies and among gender and ethnic groups. The World Health Organization currently defines overweight as a BMI of 25-29.9 kg/m 2 and obese as a BMI Z30 kg/m 2 . 20 However, compared to Caucasians, Chinese people appear to have a higher body fat percentage given the same BMI. 5 Specifically, 32 percent body fat, which is considered obese by the WHO, corresponded to a BMI of only 21.2 kg/m 2 in Chinese women, which is considered Furthermore, given the strong correlation between central and overall obesity, and the hig...

Body mass index and colon cancer risk in Chinese people: Menopause as an effect modifier

“…It has been shown that Chinese women with BMI of only 21.2 kg/ m 2 , which is considered optimal by US standards [37], have 32% of body fat, which is considered obese by the WHO [33]. Furthermore, in this relatively lean population, higher BMI (>23) was clearly associated with an increasing prevalence of obesity co-morbidities, including diabetes and metabolic syndrome [25], which are closely associated with obesity-related hyperinsulinaemia [38][39][40]. Taken together, these may explain, at least in part, the increases in colon cancer risk even with relatively small excesses in BMI among our study population although the biological explanations for this finding could be more complex.…”

Body size measurements as predictors of type 2 diabetes in Aboriginal people

“…Several studies in nonAboriginal populations suggested that waist circumference was the best obesity-related predictor of type 2 diabetes. 1,2 We found that waist circumference predicted the risk of cardiovascular disease better than body mass index (BMI) and waist-to-hip ratio in an Australian Aboriginal population. 3 There is increasing interest in investigating the separate contributions of waist and hip circumferences to diabetes, demonstrating a protective effect of a large hip circumference in non-Aboriginal populations.…”

Association between Anthropometric Parameters (WC, BMI, WHR) and Type 2 Diabetes in the Adult Yazd Population, Iran

“…There is conflicting evidence on the index of obesity that best reflects diabetic risk. In some studies, waist circumference [19,26,27] and waist-to-hip ratio [28] are better than BMI, in others, BMI is better [29,30] and in others, neither is significantly better [31]. Moreover, both types of obesity (central and overall obesity) may be independent predictors of diabetic risk [32,33].…”