title: The influence of waist circumference on insulin resistance and nonalcoholic fatty liver disease in apparently healthy Korean adults.
abstract: OBJECTIVE
  Waist circumference (WC) is a risk factor for metabolic syndrome and is related to insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD). The purpose of this study was to determine the association between WC and IR and NAFLD in apparently healthy Korean adults.
  
  
  METHODS
  The volunteers included in this cross-sectional study comprised 9,159 adults (5,052 men, 4,107 women) who participated in a comprehensive health checkup program. IR was evaluated by the homeostasis model assessment of IR (HOMA-IR) and was considered to be present when the HOMA-IR score was >2. NAFLD was evaluated by ultrasound examination. Elevated alanine aminotransferase (ALT) was defined as >40 IU/L in men and >35 IU/L in women. Logistic regression was performed to determine the odds ratios (ORs) and 95% confidence intervals (95% CIs) for NAFLD, IR, and ALT according to categorized levels of WC.
  
  
  RESULTS
  NAFLD was found in 2,553 (27.9%) of the participants (82.6% men, 17.4% women), while IR and elevated ALT were found in 17.2% (68.1% men, 31.9% women) and 10% (83% men, 17% women), respectively. After adjusting for confounding factors, the prevalence of NAFLD, IR, and elevated ALT was significantly associated with increases in WC quartile: highest quartile for NAFLD in men, OR=15.539, 95% CI=12.687-19.033; highest quartile for NAFLD in women, OR=48.732, 95% CI=23.918-99.288 (P<0.001); and highest quartile for IR in men, OR=17.576, 95% CI=13.283-23.255; highest quartile for IR in women, OR=11.078, 95% CI=7.813-15.708 (P<0.001); highest quartile for elevated ALT in men, OR=7.952, 95% CI=6.046-10.459; and highest quartile for elevated ALT in women, OR=8.487, 95% CI=4.679-15.395 (P<0.001).
  
  
  CONCLUSIONS
  WC contributes to IR and NAFLD in apparently healthy Korean adults, and thus may be an important factor in the development of IR and NAFLD.
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Deok Yun
authors.initials: DY
authors.lastname: Ju
authors.forename: Young Gil
authors.initials: YG
authors.lastname: Choe
authors.forename: Yong Kyun
authors.initials: YK
authors.lastname: Cho
authors.forename: Dong Suk
authors.initials: DS
authors.lastname: Shin
authors.forename: Su Hyeon
authors.initials: SH
authors.lastname: Yoo
authors.forename: Seo Hyoung
authors.initials: SH
authors.lastname: Yim
authors.forename: Ji Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Hong Joo
authors.initials: HJ
authors.lastname: Kim
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Park
authors.forename: Chong Il
authors.initials: CI
authors.lastname: Sohn
authors.forename: Woo Kyu
authors.initials: WK
authors.lastname: Jeon
authors.forename: Byung Ik
authors.initials: BI
authors.lastname: Kim
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D019540:Area Under Curve; D044466:Asian People; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D016017:Odds Ratio; D056910:Republic of Korea; D012307:Risk Factors; D055105:Waist Circumference
chemical_list: D000410:Alanine Transaminase
keywords: Insulin resistance; Nonalcoholic fatty liver disease; Waist circumference