Are Asians at greater mortality risks for being overweight than Caucasians? Redefining obesity for Asians

• Published in: Public health nutrition Vol. 12; no. 4; pp. 497 - 506
• Main Authors: Wen, Chi Pang, David Cheng, Ting Yuan, Tsai, Shan Pou, Chan, Hui Ting, Hsu, Hui Ling, Hsu, Chih Cheng, Eriksen, Michael P
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.04.2009
• Subjects: Adult; Age; Age groups; Aged; Alcohol; Asian Continental Ancestry Group; Asian People; Asians; at-risk population; Body fat; Body Mass Index; Body weight; Cardiovascular Diseases; Cardiovascular Diseases - mortality; Cohort Studies; diet-related diseases; Disease control; disease prevalence; epidemiology; ethnology; European Continental Ancestry Group; Exercise; Fatalities; Female; Gender; Health risks; human diseases; human nutrition; Humans; Male; Middle Aged; Morbidity; Mortality; Mortality risk; Nutrition; Obesity; Obesity - ethnology; Obesity - mortality; Overweight; Overweight - ethnology; Physical examinations; Prevalence; Proportional Hazards Models; Public health; Questionnaires; reference standards; Reference Values; Regression analysis; Risk; risk groups; Smoking; Taiwan; Taiwan - epidemiology; White People; Whites; World Health Organization; Young Adult; Taiwan; United States > US; IW, Pacific; ISEW, Taiwan; Body mass index; Obesity; Mortality risk; Overweight
• ISSN: 1368-9800; 1475-2727; 1475-2727
• DOI: 10.1017/S1368980008002802

To assess whether overweight Asians, assessed on the basis of WHO criteria, are at greater mortality risk than overweight Caucasians, and to determine whether alternative cut-off points (BMI = 23.0-24.9 kg/m2 for overweight and BMI >or= 25.0 kg/m2 for obesity) suggested by the WHO Western Pacific Regional Office are appropriate. The cohort was followed prospectively until the end of 2001. All-cause and CVD mortality risks of the overweight and obese group, relative to the reference group (BMI = 18.5-24.9 or 18.5-22.9 kg/m2), were assessed using Cox regression analysis, adjusting for age, smoking and gender. Excess deaths were estimated with a method proposed by the US Centers for Disease Control and Prevention. National Health Interview Survey (NHIS 2001) and a middle-aged perspective cohort in Taiwan. Subjects comprised 36 386 civil servants and school teachers, aged 40 years and older, who underwent a medical examination during 1989-1992. In the WHO-defined overweight group, Asians showed a significant increase in all-cause mortality risk compared with Caucasians. Asians showed risks equivalent to Caucasians' at lower BMI (around 5 units). Every unit of BMI increase, at 25.0 kg/m2 or above, was associated with a 9 % increase in relative mortality risk from all causes. Applying a cut-off point of 25.0 kg/m2 for obesity would result a prevalence of 27.1 %, while the traditional WHO cut-off point of 30.0 kg/m2 yielded obesity prevalence of 4.1 %. Excess deaths due to obesity accounted for 8.6 % of all deaths and 21.1 % of CVD deaths, based on the alternative cut-offs. In this Asian population, significant mortality risks started at BMI >or= 25.0 kg/m2, rather than at BMI >or= 30.0 kg/m2. The study supports the use of BMI >or= 25.0 kg/m2 as a new cut-off point for obesity and BMI = 23.0-24.9 kg/m2 for overweight. The magnitude of obesity-attributable deaths has been hitherto under-appreciated among Asians.