title: Twenty-four-hour work shifts, increased job demands, and elevated blood pressure in professional firefighters.
abstract: OBJECTIVE
  To investigate whether working conditions (number of 24-h shifts, number of calls, sedentary work, job strain, effort-reward imbalance, and physical demands) are associated with elevated blood pressure and hypertension among professional firefighters.
  
  
  METHODS
  A total of 330 (321 males and 9 females) firefighters were chosen for this study among the Southern California firefighters who participated in a work and obesity project. Working conditions were measured with a firefighter-specific occupational health questionnaire. Blood pressure was clinically assessed, and hypertension was defined according to the contemporary standard classification.
  
  
  RESULTS
  About 11 % of the firefighters had hypertension. Fifty percent of the hypertensive firefighters (mostly mild hypertensive) had uncontrolled high blood pressure. Hypertension was more prevalent in male, older, and high-rank firefighters and firefighter who reported low numbers of daily calls. In male firefighters who were normotensive or hypertensive without taking anti-hypertensive medication, additional 24-h shifts in the past month increased the risk of elevated diastolic blood pressure (DBP) than those who reported a standard work schedule (eight to eleven 24-h shifts). Particularly, firefighters who reported sixteen 24-h shifts had 5.0 mmHg higher DBP (p < 0.01). Body mass index attenuated the association between number of shifts and blood pressure to some extent. Firefighters who reported "increased job demands over the past years" had 3.0 mmHg (p = 0.06) higher systolic blood pressure. Other working conditions were not associated with elevated blood pressure and hypertension.
  
  
  CONCLUSIONS
  Many additional 24-h shifts and increased job demands were risk factors for elevated blood pressure in male firefighters. Optimal collective and individual workload and improved hypertension management are warranted for enhancing the cardiovascular health of firefighters.
authors.affiliation: Center for Occupational and Environmental Health, University of California, Irvine, 100 Theory, Suite 100, Irvine, CA, 92617, USA. b.choi@uci.edu.|Program in Public Health, University of California, Irvine, Irvine, CA, USA. b.choi@uci.edu.
authors.forename: BongKyoo
authors.initials: B
authors.lastname: Choi
authors.affiliation: Center for Occupational and Environmental Health, University of California, Irvine, 100 Theory, Suite 100, Irvine, CA, 92617, USA.|Center for Social Epidemiology, Marina del Rey, CA, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Schnall
authors.affiliation: Center for Occupational and Environmental Health, University of California, Irvine, 100 Theory, Suite 100, Irvine, CA, 92617, USA.|Center for Social Epidemiology, Marina del Rey, CA, USA.
authors.forename: Marnie
authors.initials: M
authors.lastname: Dobson
mesh_terms: D000328:Adult; D000367:Age Factors; D001794:Blood Pressure; D001795:Blood Pressure Determination; D015992:Body Mass Index; D005260:Female; D061388:Firefighters; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D014940:Work Schedule Tolerance; D016526:Workload / Q000523:psychology*
keywords: Anti-hypertensive medication; Body mass index; Effort–reward imbalance; Health-related behaviors; Hypertension; Job strain