title: Relationship between sleep duration and clustering of metabolic syndrome diagnostic components.
abstract: OBJECTIVE
  To examine the relation between sleep duration and metabolic syndrome (MetS).
  
  
  METHODS
  We examined the baseline data from 4356 healthy workers (3556 men and 800 women) aged 19-69 years. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). We defined four components of MetS diagnostic components in this study as follows: 1) high blood pressure (BP) systolic BP [SBP] ≥ 130 mmHg, or diastolic BP [DBP] ≥ 85 mmHg, or on medication; 2) dyslipidemia (high-density lipoprotein-cholesterol concentration <40 mg/dL, or triglycerides concentration ≥150 mg/dL, or on medication; 3) impaired glucose tolerance (fasting blood sugar concentration ≥ 110 mg/dL, or if less than 8 hours after meals ≥ 140 mg/dL), or on medication; and 4) overweight (body mass index [BMI] ≥ 25 kg/m(2)), or obesity (BMI ≥ 30 kg/m(2)). There were 680 participants in the group, with sleep duration <6 hours (15.6%).
  
  
  RESULTS
  Those who had 0-4 MetS diagnostic components, including overweight, accounted for 2159, 1222, 674, 255, and 46 participants, respectively, in the Poisson distribution. Poisson regression analysis revealed that independent factors that contributed to the number of MetS diagnostic components were being male (regression coefficient b = 0.752, P < 0.001), age (b = 0.026, P < 0.001), IPAQ classification (b = -0.238, P = 0.034), and alcohol intake (mL/day) (b = 0.018, P < 0.001). Short sleep duration (<6 hours) was also related to the number of MetS (b = 0.162, P < 0.001). The results of analyses with obesity component showed a similar association.
  
  
  CONCLUSIONS
  Short sleep duration was positively associated with the number of MetS diagnostic components independent of other lifestyle habits.
authors.affiliation: Cardiovascular Epidemiology, Kyoto Women's University, Kyoto, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Katano
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Aki
authors.initials: A
authors.lastname: Nakamura
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