title: Clinical significance of serum ferritin level as an independent predictor of insulin resistance in Korean men.
abstract: OBJECTIVE
  Elevated serum ferritin level has been reported to be associated with type 2 diabetes mellitus and metabolic syndrome, which have significant relation with insulin resistance (IR). However, clinical association between serum ferritin level and IR remained unclear. Accordingly, this study was designed to evaluate the longitudinal effects of baseline serum ferritin level on the development of IR.
  
  
  METHODS
  An IR-free 22,057 healthy Korean men (HOMA-IR<2.7), who had participated in a medical health check-up program in 2005, were followed up until 2010. During follow up, the development rate of IR, defined in case of HOMA-IR≥2.7, was monitored according to the quartile groups of serum ferritin levels. Cox proportional hazards models were used to measure the hazard ratios (HRs) of baseline serum ferritin levels on IR.
  
  
  RESULTS
  During 77,471.1 person-years of follow-up, 4494 incident cases of insulin resistance developed between 2006 and 2010 (overall development rate: 20.4%). The development rate of IR increased in proportion to the baseline serum ferritin levels (quartile 1: 16.7%, quartile 2: 18.5%, quartile 3: 19.9%, quartile 4: 25.5%, P<0.001). After adjusting for multiple covariates, the HRs (95% CI) for IR, comparing the second to the fourth quartile of serum ferritin levels with the first quartile, were 1.11 (0.99-1.24), 1.19 (1.07-1.33) and 1.51 (1.35-1.68), respectively (P for trend <0.001).
  
  
  CONCLUSIONS
  Elevated serum ferritin level was independently associated with the future development of IR in Korean men.
authors.affiliation: Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea; Department of Preventive Medicine, School of Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Sung Keun
authors.initials: SK
authors.lastname: Park
authors.affiliation: Department of Anesthesiology and Pain Medicine, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Republic of Korea.
authors.forename: Won Joon
authors.initials: WJ
authors.lastname: Choi
authors.affiliation: The Korea Central Cancer Registry, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Chang-Mo
authors.initials: CM
authors.lastname: Oh
authors.affiliation: Department of Occupational and Environmental Medicine, Dongguk University, Gyeongju Hospital, Gyeongju, Republic of Korea.
authors.forename: Min-Gi
authors.initials: MG
authors.lastname: Kim
authors.affiliation: Department of Physical Education, Graduate School, Sangji University, Wonju, Republic of Korea.
authors.forename: Woo Taek
authors.initials: WT
authors.lastname: Ham
authors.affiliation: Department of Preventive Medicine, School of Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Joong-Myung
authors.initials: JM
authors.lastname: Choi
authors.affiliation: Department of Preventive Medicine, School of Medicine, Kyung Hee University, Seoul, Republic of Korea. Electronic address: armani131@naver.com.
authors.forename: Jae-Hong
authors.initials: JH
authors.lastname: Ryoo
mesh_terms: D000328:Adult; D044466:Asian People; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D005293:Ferritins / Q000097:blood*; D006801:Humans; D015994:Incidence; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D056910:Republic of Korea / Q000453:epidemiology
chemical_list: D005293:Ferritins
keywords: Ferritin; Insulin resistance, HOMA-IR