The Risk Of Mortality And Cardiovascular Disease Is Increased In Firefighters With Elevated Blood Pressure Compared To The General Population

Objective: Firefighters are known to have increased risk of cardiovascular disease when on duty. However, there are no studies that investigated how blood pressure levels affect the cardiovascular risk of firefighters when compared to age-gender matched control. Design and method: This retrospective cohort study evaluated the effects of baseline blood pressure levels on the risk of major adverse cardiovascular events (MACE; a composite of cardiovascular death, myocardial infarction, ischemic stroke, and hemorrhagic stroke). This cohort consists of 8,242 firefighters and age-, sex-matched 28,678 controls from the Korean National Health Insurance Service database (2002–2015). The Cox proportional hazards regression model was used to adjust for age, sex, household income, BMI, smoking status, medical history, frequency of alcohol drinking, and frequency of physical activity to estimate the HRs for incident MACE events associated with firefighters compared to those of matched control from the general population. Results: Firefighters had a significantly higher risk of death or hospitalization due to MACE (HR, 1.20; 95% CI, 1.09–1.31), and myocardial infarction (HR, 1.22; 95% CI, 1.10–1.35) compared to control. When blood pressure levels were stratified according to the 2017 ACC/AHA guideline, Firefighters were not associated with increased risk of MACE in those with normal blood pressure category compared to age-, sex- matched controls as reference. However, the risk of MACE of firefighters was higher in those with elevated blood pressure (HR, 1.44; 95% CI, 1.10–1.90), stage 1 hypertension (HR, 1.12; 95% CI, 0.97–1.29) and stage 2 hypertension category (HR, 1.28; 95% CI, 1.12–1.47) compared to age-gender matched controls. Similar trends for increase in the risk of new onset myocardial infarction and ischemic stroke in firefighters with elevated BP and hypertension was demonstrated. Conclusions: Firefighters have significantly increased adjusted risk of cardiovascular disease. Firefighters with higher blood pressure showed significantly higher cardiovascular risk than controls with same blood pressure category. The results suggest, for the first time, that certain occupations who are exposed to extreme work conditions may be at higher risk for adverse prognosis in subjects with elevated blood pressure and hypertension.