title: Association of overtime work and hypertension in a Japanese working population: a cross-sectional study.
abstract: Long working hours have been associated with an increased risk of cardiovascular disease, but its relationship with hypertension remains unclear. The objective of this study is to examine the relationship between overtime and presence of hypertension using data from a large-scale multi-company study in Japan. Participants were 52 365 workers of four companies that provided both health-checkup data and self-reported data on overtime worked. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, and/or the use of antihypertensive drug. Logistic regression analysis was performed to determine the odds ratio for hypertension for each category of overtime work (<45, 45-79, 80-99 or ≥100 h/month) with adjustments for age, sex, company, smoking status and body mass index. The prevalence of hypertension tended to decrease with increasing overtime work: 17.5, 12.0, 11.1 and 9.1% for the shortest (<45 h/month) through the longest overtime category (≥100 h/month). The age-, sex- and company-adjusted odds ratios (95% confidence interval) were 1.00 (reference), 0.81 (0.75-0.86), 0.73 (0.62-0.86), 0.58 (0.44-0.76), respectively (p for linear trend <0.001). In a sub-cohort, the inverse association remained statistically significant after an additional adjustment for other potential confounders. Results of the present large-scale study among Japanese workers suggest an inverse association between overtime work and presence of hypertension.
authors.affiliation: Azbil Corporation , Tokyo , Japan .
authors.forename: Teppei
authors.initials: T
authors.lastname: Imai
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kuwahara
authors.forename: Akiko
authors.initials: A
authors.lastname: Nishihara
authors.forename: Tohru
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Toru
authors.initials: T
authors.lastname: Honda
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kochi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Eguchi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Uehara
authors.forename: Reiko
authors.initials: R
authors.lastname: Kuroda
authors.forename: Daisuke
authors.initials: D
authors.lastname: Omoto
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Nagata
authors.forename: Ngoc Minh
authors.initials: NM
authors.lastname: Pham
authors.forename: Kayo
authors.initials: K
authors.lastname: Kurotani
authors.forename: Akiko
authors.initials: A
authors.lastname: Nanri
authors.forename: Shamima
authors.initials: S
authors.lastname: Akter
authors.forename: Isamu
authors.initials: I
authors.lastname: Kabe
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizoue
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Sone
authors.forename: Seitaro
authors.initials: S
authors.lastname: Dohi
mesh_terms: D000328:Adult; D044466:Asian People; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000209:etiology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology*; D016272:Occupational Health; D015995:Prevalence; D012307:Risk Factors; D014940:Work Schedule Tolerance / Q000502:physiology*; D016526:Workload
keywords: Cross-sectional study; Japan; hypertension; long working hours