title: Meta-analysis on night shift work and risk of metabolic syndrome.
abstract: This study aims to quantitatively summarize the association between night shift work and the risk of metabolic syndrome (MetS), with special reference to the dose-response relationship with years of night shift work. We systematically searched all observational studies published in English on PubMed and Embase from 1971 to 2013. We extracted effect measures (relative risk, RR; or odd ratio, OR) with 95% confidence interval (CI) from individual studies to generate pooled results using meta-analysis approach. Pooled RR was calculated using random- or fixed-effect model. Downs and Black scale was applied to assess the methodological quality of included studies. A total of 13 studies were included. The pooled RR for the association between 'ever exposed to night shift work' and MetS risk was 1.57 (95% CI = 1.24-1.98, pheterogeneity  = 0.001), while a higher risk was indicated in workers with longer exposure to night shifts (RR = 1.77, 95% CI = 1.32-2.36, pheterogeneity  = 0.936). Further stratification analysis demonstrated a higher pooled effect of 1.84 (95% CI = 1.45-2.34) for studies using the NCEP-ATPIII criteria, among female workers (RR = 1.61, 95% CI = 1.10-2.34) and the countries other than Asia (RR = 1.65, 95% CI = 1.39-1.95). Sensitivity analysis confirmed the robustness of the results. No evidence of publication bias was detected. The present meta-analysis suggested that night shift work is significantly associated with the risk of MetS, and a positive dose-response relationship with duration of exposure was indicated.
authors.affiliation: JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China; CUHK Centre for Public Health and Primary Care (Shenzhen), Shenzhen Research Institute of the Chinese University of Hong Kong, Shenzhen, China.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: He
authors.forename: S
authors.initials: S
authors.lastname: Xie
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: X
authors.initials: X
authors.lastname: Miao
authors.forename: E Y Y
authors.initials: EY
authors.lastname: Chan
authors.forename: J L
authors.initials: JL
authors.lastname: Tang
authors.forename: M C S
authors.initials: MC
authors.lastname: Wong
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: I T S
authors.initials: IT
authors.lastname: Yu
authors.forename: L A
authors.initials: LA
authors.lastname: Tse
mesh_terms: D006801:Humans; D024821:Metabolic Syndrome / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D009784:Occupational Diseases / Q000503:physiopathology* / Q000517:prevention & control; D016017:Odds Ratio; D012307:Risk Factors; D014937:Work; D014940:Work Schedule Tolerance
keywords: Metabolic syndrome; night work; shift work