BACKGROUND: The association between body mass index (BMI) and mortality is not conclusive, especially in East Asian populations. Furthermore, the association has been neither supported by recent data, nor assessed after controlling for weight changes. METHODS: We evaluated the relationship between BMI and all-cause or cause-specific mortality, using prospective cohort data by the National Health Insurance Service in Korea, which consisted of more than one million subjects. A total of 153,484 Korean adults over 30 years of age without pre-existing @entity65 or @entity5 at baseline were followed-up until 2010 (mean follow-up period = 7.91    0.59 years). Study subjects repeatedly measured body weight 3.99 times, on average. RESULTS: During follow-up, 3,937 total @entity204 occurred; 557 @entity204 from @entity65 , and 1,224 from @entity5 . In multiple-adjusted analyses, U-shaped associations were found between BMI and mortality from any cause, @entity65 , and @entity5 after adjustment for age, sex, smoking status, @entity285 consumption, physical activity, socioeconomic status, and weight change. Subjects with a BMI < 23 kg/m2 and >=  30 kg/m2 had higher risks of all-cause and cause-specific mortality compared with the reference group (BMI 23-24.9 kg/m2). The lowest risk of all-cause mortality was observed in subjects with a BMI of 25-26.4 kg/m2 (adjusted hazard ratio [HR] 0.86; 95% CI 0.77 to 0.97). In subgroup analyses, including the elderly and those with @entity102 ( @entity6 , @entity101 , and @entity740 ), subjects with a BMI of 25-29.9 kg/m2 (moderate @entity28 ) had a lower risk of mortality compared with the reference. However, this association has been attenuated in younger individuals, in those with higher socioeconomic status, and those without @entity102 . CONCLUSION: Moderate @entity28 was associated more strongly with a lower risk of mortality than with normal, underweight, and overweight groups in the general population of South Korea. This @entity28 paradox was prominent in not only the elderly but also individuals with @entity102 .

Body Mass Index and Mortality in the General Population and in Subjects with XXXX in Korea: A Nationwide Cohort Study (2002-2010).

@entity101 :: ('MESH:D006973', 'Disease') :: ['hypertension'] @entity6 :: ('MESH:D003920', 'Disease') :: ['diabetes mellitus'] @entity28 :: ('MESH:D009765', 'Disease') :: ['obesity'] @entity5 :: ('MESH:D009369', 'Disease') :: ['cancer'] @entity102 :: ('MESH:D002908', 'Disease') :: ['chronic disease', 'chronic diseases'] @entity740 :: ('MESH:D051436', 'Disease') :: ['chronic kidney disease'] @entity285 :: ('D000431', 'Chemical') :: ['alcohol'] @entity204 :: ('MESH:D003643', 'Disease') :: ['deaths'] @entity65 :: ('MESH:D002318', 'Disease') :: ['cardiovascular disease']
@entity102 :: (MESH:D002908,Disease) :: ['Chronic Disease']
