Year of Publication

2015

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Education

Department

Kinesiology and Health Promotion

First Advisor

Dr. Mark Abel

Abstract

This dissertation is composed of two manuscripts assessing cardiovascular disease (CVD) risk in structural firefighters. Study 1 compared traditional CVD risk factors and health-related behaviors between professional and volunteer firefighters. Online questionnaires were sent to approximately 4000 firefighters in the state of Kentucky. The results indicated that 90% of volunteer and 58% of professional firefighters were classified as moderate-to-high CVD risk. Volunteer firefighters were significantly (p < 0.001) older and more likely (p = 0.026) to be current cigarette smokers. The mean body mass index among all firefighters in the sample was 30.8 kg·m-2. Nearly 60% of volunteer firefighters were obese. Obese firefighters were more likely (p < 0.05) to have been diagnosed as diabetic or pre-diabetes compared to overweight and normal weight firefighters. These results indicate that volunteer firefighters may be at a greater CVD risk compared to professional firefighters.

Study 2 investigated the association of cardiorespiratory fitness (CRF) and body fat with arterial stiffness in professional firefighters. Forty-six male professional structural firefighters performed a maximal graded exercise test in personal protective equipment and noninvasive arterial stiffness assessments before and for 60 minutes post-exercise. Percent body fat was measured with a bioelectrical impedance analyzer. Firefighters were stratified into fit (VO2peak ≥ 48.3 ml·kg-1·min-1) and unfit (VO2peak < 48.3 ml·kg-1·min-1) groups. Pulse wave velocity, an indicator of arterial stiffness, was significantly lower overall in the fit group compared to the unfit group (p < 0.001). However, the fit group had significantly less relative body fat compared to the unfit group. Thus, when controlling for the confounding effects of fatness, the results indicated that there was a significant effect of relative body fat (p < 0.001) but no effect of fitness on arterial stiffness (p = 0.490). This indicated that relative body fat was responsible for the difference in arterial stiffness and not the fitness stratification. The unfit group displayed a significantly higher average carotid-femoral pulse wave velocity of 1.004 m·s-1 which may increase the risk of a sudden cardiac event by 14%. In addition, there was no main effect for time (p = 0.794) or group x time interaction (p = 0.906). Most resting measures of central and brachial pressure were significantly higher in the unfit group.

Results from this dissertation indicated that volunteer firefighters have a greater CVD risk than professional firefighters. Furthermore, relative body fat has a greater effect on arterial stiffness than cardiorespiratory fitness. Collectively, these findings indicate the need for innovative weight management strategies to decrease CVD risk among structural firefighters.

Share

COinS