title: Serum Ferritin, Insulin Resistance, and β-cell Dysfunction: A Prospective Study in Normoglycemic Japanese Men.
abstract: Objectives:The present cohort study investigated the relationship between serum ferritin levels and indices of insulin resistance and β-cell dysfunction in a normoglycemic population without iron overload disorders.Methods:The study participants included 575 normoglycemic Japanese men aged 35-57 years with serum ferritin levels of 400 μg/L or less. Insulin resistance and β-cell dysfunction were estimated at baseline and after 3 years by the homeostasis model assessments of insulin resistance and β-cell function (HOMA-IR and HOMA-β, respectively). To compare the subsequent changes in HOMA-IR and HOMA-β over a 3-year follow-up period among 3 groups based on tertiles of baseline serum ferritin levels (4.9-87.1, 87.2-140.5, and 140.6-396.8 μg/L), the geometric mean HOMA-IR and HOMA-β values at year 3 were calculated for each group using analysis of covariance, incorporating the respective log-transformed parameters at baseline in addition to age, body mass index and major confounding factors.Results:The multivariate-adjusted geometric mean HOMA-IR at year 3 was significantly higher in those in the highest and middle serum ferritin tertiles (1.24 and 1.22, respectively), compared with the lowest tertile (1.07) (p=0.009). When the total study participants were stratified by median body mass index (22.72 kg/m2), similar positive relationships were observed between serum ferritin levels and HOMA-IR for both obese and non-obese participants. However, the adjusted geometric mean HOMA-β at year 3 was similar among the 3 serum ferritin groups.Conclusions:Elevated serum ferritin levels predicted a subsequent increase in HOMA-IR in normoglycemic Japanese men without iron overload disorders.
authors.affiliation: Department of Public Health, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Koshi
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Social and Environmental Medicine, Kanazawa Medical University, Uchinada, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Sakurai
authors.affiliation: School of Nursing, Kanazawa Medical University, Uchinada, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Morikawa
authors.affiliation: Department of Epidemiology and Public Health, Kanazawa Medical University, Uchinada, Japan.
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Nagasawa
authors.affiliation: Department of Public Health, and Center for Epidemiologic Research in Asia, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Miura
authors.affiliation: Department of Social and Environmental Medicine, Kanazawa Medical University, Uchinada, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Ishizaki
authors.affiliation: School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Kido
authors.affiliation: Department of Social Walfare, Toyama College of Welfare Science, Imizu, Japan.
authors.forename: Yuchi
authors.initials: Y
authors.lastname: Naruse
authors.affiliation: School of Nursing, Kanazawa Medical University, Uchinada, Japan.
authors.forename: Motoko
authors.initials: M
authors.lastname: Nakashima
authors.affiliation: Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nogawa
authors.affiliation: Department of Occupational and Environmental Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Suwazono
authors.affiliation: Medical Research Institute, Kanazawa Medical University, Uchinada, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakagawa
mesh_terms: D000328:Adult; D044466:Asian People; D005293:Ferritins / Q000097:blood*; D005500:Follow-Up Studies; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007564:Japan; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D005293:Ferritins