title: All-Cause and Cardiovascular Mortality Among Koreans: Effects of Obesity and Metabolic Health.
abstract: BACKGROUND
  The effect of obesity on mortality in people with metabolic syndrome (MetS) risk factors, but without pre-existing diabetes; hypertension; or cardiovascular disease (CVD), is uncertain. The purpose of this study is to investigate the effect of obesity and MetS risk factors on CVD and all-cause mortality in an Asian cohort.
  
  
  METHODS
  This retrospective study included 275,867 Koreans (56.6% men) who participated in an occupational health program between 2002 and 2009. At baseline, four groups were defined, according to the absence/presence of obesity (defined by BMI < or ≥25, respectively) and zero or one or more MetS features, respectively: metabolically healthy non-obese (MHNO; reference group); metabolically healthy obese (MHO); metabolically unhealthy obese (MUO); and metabolically unhealthy non-obese (MUNO). Hazard ratios (HRs) and 95% CIs for CVD and all-cause mortality at follow-up were estimated using Cox proportional hazards models.
  
  
  RESULTS
  During follow-up, 1,060 deaths (187 from CVD) occurred. After adjusting for age, sex, alcohol intake, exercise, and educational status, CVD mortality risk was not increased in the MHO group (HR=0.50, 95% CI=0.15, 1.66), whereas risk was increased in the MUO and MUNO groups (HR=1.81, 95% CI=1.12, 2.91; HR=1.84, 95% CI=1.15, 2.92, respectively). HRs for all-cause mortality in both obese groups were not different from the reference group. When subjects with prior diabetes, CVD, and hypertension were excluded, CVD mortality was not significantly different in the MUO and MUNO groups from the reference group.
  
  
  CONCLUSIONS
  Comorbid diabetes, hypertension, or CVD explain much of the increased risk of CVD mortality in obese individuals.
authors.affiliation: Division of Cardiology, Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: kcmd.sung@samsung.com.
authors.forename: Ki-Chul
authors.initials: KC
authors.lastname: Sung
authors.affiliation: Department of Occupational and Environmental Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seungho
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Division of Cardiology, Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Eun Sun
authors.initials: ES
authors.lastname: Cheong
authors.affiliation: Division of Cardiology, Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Bum Soo
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Byung Jin
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yong-Bum
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Pil-Wook
authors.initials: PW
authors.lastname: Chung
authors.affiliation: Centre for Population Health Sciences, University of Edinburgh, Southampton General Hospital (University of Southampton) and Southampton National Institute for Health Research Biomedical Research Centre, Southampton, United Kingdom.
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Wild
authors.affiliation: Nutrition and Metabolism Unit, IDS Building, Southampton General Hospital (University of Southampton) and Southampton National Institute for Health Research Biomedical Research Centre, Southampton, United Kingdom.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Byrne
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D016016:Proportional Hazards Models; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors