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


METHODS
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.


METHODS
National Health Interview Survey (NHIS 2001) and a middle-aged perspective cohort in Taiwan.


METHODS
Subjects comprised 36 386 civil servants and school teachers, aged 40 years and older, who underwent a medical examination during 1989-1992.


RESULTS
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.


CONCLUSIONS
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.
Center for Health Policy Research and Development, National Health Research Institutes, Miaoli County, Taiwan, Republic of China. cwengood@nhri.org.tw
Chi Pang
CP
Wen
Ting Yuan
TY
David Cheng
Shan Pou
SP
Tsai
Hui Ting
HT
Chan
Hui Ling
HL
Hsu
Chih Cheng
CC
Hsu
Michael P
MP
Eriksen
D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology* / Q000401:mortality; D050177:Overweight / Q000208:ethnology*; D015995:Prevalence; D016016:Proportional Hazards Models; D012016:Reference Values; D012306:Risk; D012907:Smoking; D013624:Taiwan / Q000453:epidemiology; D044465:White People; D055815:Young Adult