title: Relationship between shift work and clustering of the metabolic syndrome diagnostic components.
abstract: OBJECTIVE
  To examine the relationship between the type of work and the number of metabolic syndrome diagnostic components(MetS-DC), as well as the risk of MetS, with adjustment for lifestyle habits in Japanese workers.
  
  
  METHODS
  We examined the baseline data from 4,427 participants(81.4% male) aged 19 to 69 years old. The physical activity of each participant was classified according to the International Physical Activity Questionnaire(IPAQ). We defined the four MetS-DC in this study as follows: 1) high blood pressure(BP): systolic BP ≥130 mmHg, or diastolic BP ≥85 mmHg, or the use of antihypertensive drugs; 2) dyslipidemia: high-density lipoprotein-cholesterol concentration ＜40 mg/dl or triglyceride concentration ≥150 mg/dl, or on medication for dyslipidemia; 3) dysglycemia: fasting blood sugar level ≥110 mg/dl, or if less than eight hours after meals ≥140mg/dl, or on medication for diabetes mellitus; 4) overweight: a body mass index ≥25kg/m(2). We defined MetS as overweight plus two or more of the MetS-DC.
  
  
  RESULTS
  There were 3,094 subjects in the daytime work group, 73 in the fixed nighttime work group, 1,017 in the shift work group and 243 in the day-to-night work group. The Poisson regression analysis revealed that fixed nighttime (regression coefficient [b]=-0.233, P=0.028) and shift work (b=0.098, P=0.034) independently contributed to the number of MetS-DC, compared to daytime work. The multivariate logistic analysis not including sleep hours in the model showed that shift work was positively related to MetS (odd ratio=1.47, P＜0.01).
  
  
  CONCLUSIONS
  Shift work were significantly associated with the number of MetS-DC, and was related to risk of MetS compared to daytime work.
authors.affiliation: Cardiovascular Epidemiology, Kyoto Women's University.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kawabe
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Sayuri
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.forename: Taichiro
authors.initials: T
authors.lastname: Tanaka
authors.forename: Toru
authors.initials: T
authors.lastname: Takebayashi
authors.forename: Akira
authors.initials: A
authors.lastname: Okayama
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Miura
authors.forename: Tomonori
authors.initials: T
authors.lastname: Okamura
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ueshima
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology; D050177:Overweight; D011379:Prognosis; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014940:Work Schedule Tolerance / Q000502:physiology*; D055815:Young Adult