title: Body mass index and mortality among Korean elderly in rural communities: Kangwha Cohort Study.
abstract: BACKGROUND
  The relationship between body mass index (BMI) and mortality may differ by ethnicity, but its exact nature remains unclear among Koreans. The study aim was to prospectively examine the association between BMI and mortality in Korean.
  
  
  METHODS
  6166 residents (2636 men; 3530 women) of rural communities (Kangwha County, Republic of Korea) aged 55 and above were followed up for deaths from 1985-2008. The multivariable-adjusted hazard ratios were calculated using the Cox proportional hazards model.
  
  
  RESULTS
  During the 23.8 years of follow-up (an average of 12.5 years in men and 15.7 years in women), 2174 men and 2372 women died. Men with BMI of 21.0-27.4 and women with BMI of 20.0-27.4 had a minimal risk for all-cause mortality. A lower BMI as well as a higher BMI increased the hazard ratio of death. For example, multivariable-adjusted hazard ratios associated with BMI below 16, and with BMI of 27.5 and above, were 2.4 (95% CI = 1.6-3.5) and 1.5 (95% CI = 1.1-1.9) respectively, in men, compared to those with BMI of 23.0-24.9. This reverse J-curve association was maintained among never smokers, and among people with no known chronic diseases. Higher BMI increased vascular mortality, while lower BMI increased deaths from vascular diseases, cancers, and, especially, respiratory diseases. Except for cancers, these associations were generally weaker in women than in men.
  
  
  CONCLUSIONS
  A reverse J-curve association between BMI and all-cause mortality may exist. BMI of 21-27.4 (rather than the range suggested by WHO of 18.5-23 for Asians) may be considered a normal range with acceptable risk in Koreans aged 55 and above, and may be used as cut points for interventions. More concern should be given to people with BMI above and below a BMI range with acceptable risk. Further studies are needed to determine ethnicity-specific associations.
authors.affiliation: Department of Preventive Medicine, Graduate School of Public Health, Yonsei University, Seoul, Republic of Korea; Department of Public Health, Yonsei University Graduate School, Seoul, Republic of Korea.
authors.forename: Seri
authors.initials: S
authors.lastname: Hong
authors.affiliation: Department of Preventive Medicine and Public Health, Catholic Kwandong University College of Medicine, Gangneung, Republic of Korea.
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Yi
authors.affiliation: Department of Biomedical Laboratory Science, Eulji University College of Health Science, Sungnam, Republic of Korea.
authors.forename: Jae Woong
authors.initials: JW
authors.lastname: Sull
authors.affiliation: Health Insurance Review & Assessment Service, Seoul, Republic of Korea.
authors.forename: Jae-Seok
authors.initials: JS
authors.lastname: Hong
authors.affiliation: Department of Epidemiology and Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Republic of Korea; Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Republic of Korea.
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Jee
authors.affiliation: Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Republic of Korea; Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Heechoul
authors.initials: H
authors.lastname: Ohrr
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D009026:Mortality; D056910:Republic of Korea; D012424:Rural Population / Q000706:statistics & numerical data*