Differential Obesity Measures for the Firefighter Wellness and Fitness (WEFIT) Program: BMI, Waist Circumference, or Skin-fold Body Fat?

Most previous cardiovascular risk factor studies in firefighters have been carried out using BMI as the obesity measure. Few studies have used alternative obesity measures such as skinfold-based percent body fat and waist circumference. Few studies have explored the differential relationships of three obesity measures (body mass index (BMI), skin-fold body %, and waist circumference) with VO2 max and other CVD risk factors (i.e., hypertension and blood lipid profiles) in firefighters. This paper presents preliminary findings from the on-going FORWARD study (Choi et al., 2011) based on 28 male firefighters in a Southern California county. The adiposity of each of 28 firefighters was assessed at their Wellness and Fitness (WEFIT) exams in three ways: BMI; body fat % based on 3-site skinfolds; and waist circumference. VO2 max, blood pressure, and lipid profiles (total cholesterol, triglycerides, HDL, and LDL) were measured at their WEFIT exams. The obesity prevalence in 28 firefighters did not vary much by the three measures: BMI (≥ 30 kg/m2), 25%; skinfold body fat % (> 25%), 28.6%; and waist circumference (> 102 cm), 28.6%. BMI was more strongly correlated with waist circumference than with body fat % (Spearman rho = 0.88 vs. 0.69). BMI and waist circumference were more strongly correlated with systolic and diastolic blood pressure and triglycerides, while body fat % was more strongly correlated with HDL and VO2 max. This preliminary finding will be further tested in a much larger sample of firefighters (n > 370) at the end of the FORWARD study.