title: Working hours and incidence of metabolic syndrome and its components in a Mediterranean cohort: the SUN project.
abstract: BACKGROUND
  Metabolic syndrome (MetS) is an important and priority public health problem globally. Long working hours have been proposed as a modifiable risk factor for MetS, despite sparse epidemiological evidence. Thus, the aim of this study was to prospectively evaluate the associations between working hours and incidence of MetS and each of its components.
  
  
  METHODS
  We assessed 6845 participants of a Spanish dynamic prospective cohort of university graduates (the SUN project), initially free of any specific criteria of MetS, and followed-up for a median of 8.3 years. Weekly working hours were collected at baseline and grouped into four categories: >0-24, 25-39, 40-49 and ≥50 h. MetS was defined according to the updated harmonizing criteria. We estimated multivariable adjusted Relative Risks (RR) of MetS and their 95% Confidence Intervals (95% CI), using Poisson regression models.
  
  
  RESULTS
  The cumulative incidence of MetS was 6.0%. Working hours were not independently related to MetS (25-39 h/week = RR: 1.42, 95% CI 0.90-2.25; 40-49 h/week = RR: 1.45, 95% CI 0.91-2.30; ≥50 h/week = RR: 1.49, 95% CI 0.91-2.42, P for trend = 0.235) nor to any of its individual definition criteria.
  
  
  CONCLUSIONS
  Our findings do not suggest that long working hours increase the risk of MetS development or each of its components. Further longitudinal studies in general population should be conducted to confirm these results.
authors: 1 Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain 2 Department of Maternal and Child Nursing and Public Health, School of Nursing, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors: Adriano M
authors: AM
authors: Pimenta
authors: 1 Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
authors: Maira
authors: M
authors: Bes-Rastrollo
authors: 1 Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
authors: Carmen
authors: C
authors: Sayon-Orea
authors: 1 Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
authors: Alfredo
authors: A
authors: Gea
authors: 3 Department of Health, Technological Centre for Health Information and Documentation, Murcia, Spain.
authors: Enrique
authors: E
authors: Aguinaga-Ontoso
authors: 1 Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
authors: Roberto
authors: R
authors: Lopez-Iracheta
authors: 1 Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain 4 CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain mamartinez@unav.es.
authors: Miguel A
authors: MA
authors: Martinez-Gonzalez
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D014937:Work / Q000706:statistics & numerical data*