title: Oxidative stress and insulin resistance in policemen working shifts.
abstract: OBJECTIVE
  Shift work is a work schedule involving irregular or unusual hours, compared to those of a normal daytime work schedule. In developed countries, night shift work is very common. In several cities of our country, 12/24 shift system is implemented in police organization. While night shift work composes half of the 20 shift in a month, in ergonomic shift system, an alternative shift schedule, shift work can be performed in three shifts in a day. In this study, we aimed to investigate the effects of 12/24 shift work system on insulin resistance and oxidative stress and systemic inflammation.
  
  
  METHODS
  Two hundred and four 12/24 shift workers (age 44.3 ± 5.6 years) and 193 ergonomic shift workers (age 42.6 ± 5.5 years) were included to study. Serum oxidized LDL (ox-LDL), neutrophil gelatinase lipocalin-2 (NGAL) as oxidative stress markers, glucose, insulin, ferritin, high-sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate values were measured. Homeostasis model assessment for insulin resistance (HOMA-IR) was calculated to evaluate insulin resistance.
  
  
  RESULTS
  Serum ox-LDL, HOMA-IR, hsCRP and NGAL levels in 12/24 shift system were found to be significantly higher compared with ergonomic shift workers (p < 0.0001, p = 0.02, p = 0.03, p = 0.02, respectively). When evaluated all subjects, weak but significant correlation was found between HOMA-IR with ox-LDL (r = 0.12, p = 0.01), hsCRP (r = 0.17, p = 0.001) and ferritin (r = 0.15, r = 0.003). Also in 12/24 shift work group, there were significant correlations between HOMA-IR with hsCRP (r = 0.17, p = 0.01) and ferritin (r = 0.25, p = 0.0001).
  
  
  CONCLUSIONS
  It may be concluded that 12/24 shift system might give rise to insulin resistance and oxidative stress. Additionally, workers in this system may under risk of systemic inflammatory response. Working hours must be arranged in accordance with the physiological rhythm.
authors.affiliation: Balıkesir Police Department, Balıkesir, Turkey.
authors.forename: Irfan
authors.initials: I
authors.lastname: Demir
authors.affiliation: Department of Biochemistry, Meram Medical Faculty, Necmettin Erbakan University, Konya, Turkey. aysuntoker@gmail.com.
authors.forename: Aysun
authors.initials: A
authors.lastname: Toker
authors.affiliation: Gaziantep Police Department, Gaziantep, Turkey.
authors.forename: Selcuk
authors.initials: S
authors.lastname: Zengin
authors.affiliation: Department of Biochemistry, Medical Faculty, Ataturk University, Erzurum, Turkey.
authors.forename: Esra
authors.initials: E
authors.lastname: Laloglu
authors.affiliation: Department of Biochemistry, Medical Faculty, Ataturk University, Erzurum, Turkey.
authors.forename: Hulya
authors.initials: H
authors.lastname: Aksoy
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D000071068:Lipocalin-2 / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D016495:Police; D012307:Risk Factors; D014940:Work Schedule Tolerance / Q000502:physiology*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D000071068:Lipocalin-2; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D002097:C-Reactive Protein; D005293:Ferritins
keywords: Inflammation; Insulin resistance; Oxidative stress; Shift system