title: Increased serum ferritin levels are independently related to incidence of prediabetes in adult populations.
abstract: OBJECTIVE
  To comprehensively and exhaustively assess the relationship between serum ferritin levels and incidence of prediabetes in a prospective study.
  
  
  METHODS
  This prospective cohort study (n=7380) with a mean follow-up of 3.07 years (range: 1-7, 95% CI: 3.03-3.12) was conducted in Tianjin, China. Blood fasting glucose, oral glucose tolerance test, serum ferritin levels and other potentially confounding factors were measured at baseline and at each year of follow-up. Adjusted Cox proportional hazards regression models were used to assess the gender-specific relationship between baseline and mean serum ferritin quintiles and prediabetes.
  
  
  RESULTS
  The incidence of prediabetes was 85 per 1000 person-years among men and 44 per 1000 person-years among women during follow-up (from 2007 to 2014). After adjusting for potential confounders, hazard ratios (95% CI) for prediabetes across baseline ferritin quintiles were: for men, 1.00, 1.13 (0.90-1.40), 1.20 (0.97-1.48), 1.41 (1.14-1.73) and 1.73 (1.41-2.11); and for women, 1.00, 1.01 (0.74-1.38), 0.68 (0.48-0.96), 0.84 (0.61-1.15) and 1.07 (0.80-1.45), respectively. Similar results were also observed for mean ferritin levels.
  
  
  CONCLUSIONS
  Both baseline and mean serum ferritin levels were significantly and linearly related to prediabetes in men, whereas U-shaped relationships were observed between baseline and mean serum ferritin and prediabetes in women. The relationship between prediabetes risk and mean serum ferritin levels may be more stable than one with baseline serum ferritin levels.
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: G
authors.initials: G
authors.lastname: Meng
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: X
authors.initials: X
authors.lastname: Bao
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: H
authors.initials: H
authors.lastname: Du
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: H
authors.initials: H
authors.lastname: Shi
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: X
authors.initials: X
authors.lastname: Guo
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Su
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: L
authors.initials: L
authors.lastname: Fang
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: F
authors.initials: F
authors.lastname: Yu
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: S
authors.initials: S
authors.lastname: Sun
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: M
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Jia
authors.affiliation: Department of rehabilitation and sports medicine, Tianjin medical university, Tianjin, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: K
authors.initials: K
authors.lastname: Song
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China; Collaborative Innovation Center of Non-communicable Disease, Tianjin Medical University, Tianjin, China.
authors.forename: G
authors.initials: G
authors.lastname: Huang
authors.affiliation: Health management centre, Tianjin medical university general hospital, Tianjin, China.
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Nutritional epidemiology institute and school of public health, Tianjin medical university, Tianjin, China; Health management centre, Tianjin medical university general hospital, Tianjin, China; Collaborative Innovation Center of Non-communicable Disease, Tianjin Medical University, Tianjin, China. Electronic address: nkj0809@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Niu
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D005260:Female; D005293:Ferritins / Q000097:blood*; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood* / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D005293:Ferritins
keywords: Cohort study; Impaired fasting glucose; Insulin resistance; Prediabetes; Serum ferritin