title: Metabolic syndrome is inversely related to cardiorespiratory fitness in male career firefighters.
abstract: Cardiovascular disease (CVD) accounts for 45% of on-duty fatalities among firefighters, occurring primarily in firefighters with excess CVD risk factors in patterns resembling the metabolic syndrome (MetSyn). Additionally, firefighters have a high prevalence of obesity and sedentary behavior suggesting that MetSyn is also common. Therefore, we assessed the prevalence of MetSyn in firefighters and its association with cardiorespiratory fitness (CRF) in a cross-sectional study of 957 male career firefighters. The CRF was measured by maximal exercise tolerance testing (standard metabolic equivalent [METS]). The MetSyn was defined according to modified criteria from the Joint Scientific Statement. Group differences were compared using χ-test and logistic regression. The prevalence of MetSyn was 28.3%. Firefighters in the lowest fitness category (METS ≤ 10) had a nearly 10-fold higher prevalence of MetSyn (51.2%) compared with colleagues in the highest fitness category (METS > 14) (MetSyn prevalence 5.2%) (p value < 0.0001, adjusted for age). In multivariate regression models, every 1-unit increase in METS decreased the odds of having the MetSyn by 31% (odds ratio 0.69 [95% confidence interval 0.63-0.76] [age adjusted]), whereas age had no significant effect after adjusting for CRF. We found a high prevalence of the MetSyn in this group of career emergency responders expected to be more active, fit, and relatively younger than the general population. Moreover, there is a highly significant inverse, dose-response association with CRF. Firefighters should be given strong incentives to improve their fitness, which would decrease prevalent MetSyn, a likely precursor of on-duty CVD events and contributor to CVD burden in this population.
authors: Department of Environmental Health, Environmental and Occupational Medicine and Epidemiology (EOME), Harvard School of Public Health, Boston, Massachusetts, USA.
authors: Dorothee M
authors: DM
authors: Baur
authors: Costas A
authors: CA
authors: Christophi
authors: Stefanos N
authors: SN
authors: Kales
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality; D005080:Exercise Test; D017079:Exercise Tolerance; D061388:Firefighters / Q000706:statistics & numerical data*; D006339:Heart Rate; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis*; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness; D015995:Prevalence; D055815:Young Adult