Higher cardiorespiratory fitness is strongly associated with lower cardiovascular risk factors in firefighters: a cross-sectional study in a German fire brigade

Abstract

Previous studies have shown significant cardiovascular risks in firefighters and that they suffer from cardiovascular events, especially on duty. Otherwise, adequate cardiorespiratory fitness is considered to have a protective effect in reducing cardiovascular complications. Therefore, the study aimed to evaluate the association between cardiorespiratory fitness and cardiovascular risks factors in firefighters. We enrolled ninety-seven male German firefighters in this cross-sectional study of cardiorespiratory fitness and cardiovascular risk factors. We used spiroergometry testing to estimate oxygen consumption to determine cardiorespiratory fitness and to calculate metabolic equivalents. We evaluated cardiovascular risk factors included nicotine consumption, lipid profiles, body composition, resting blood pressure, and heart rate. We evaluated cardiovascular risk factors included nicotine consumption, lipid profiles, body composition, resting blood pressure and heart rate. The comparison of association between cardiorespiratory fitness and cardiovascular risk factors was performed by using χ²-test, analysis of variance, general linear regression with/without adjustment for age and body mass index (BMI). This study demonstrated a strong association between lower cardiovascular risk factors and higher cardiorespiratory fitness. There were significantly lower values for BMI, waist circumference, body fat percentage and resting systolic blood pressure, triglycerides, and total cholesterol (all p < 0.0443, age-adjusted) with increased cardiorespiratory fitness. Only 19.6% (n = 19) of the examined firefighters were classified as "fit and not obese", 48.4% (n = 47) were "low fit and not obese" and 30.9% (n = 30) were "low fit and obese". The results clarify that increasing cardiorespiratory fitness is a fundamental point for the reduction and prevention of cardiovascular complications in firefighters. It could be demonstrated, especially for central risk factors, particularly BMI, waist circumference, sytolic resting blood pressure and triglyceride values. Therefore, firefighters should be motivated to increase their cardiorespiratory fitness for the beneficial effect of decreasing cardiovascular risk profile.