Body Mass, Fitness and Survival in Veteran Patients: Another Obesity Paradox?
Abstract
Purpose
The paradox of obesity in patients with heart failure (HF) also has been observed in non-HF veteran patients. Veterans had to have met military fitness requirements at the time of their enlistment. Therefore, we assessed the relation of body mass index (BMI) to mortality in a clinical cohort of non-HF veterans, adjusting for fitness.
Methods
After excluding HF patients (n=580), the study population comprised 6876 consecutive patients (mean age 58 [±11] years) referred for exercise testing. Patients were classified by BMI category: normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), or obese (BMI ≥30.0 kg/m2). The association between BMI, fitness, other clinical variables, and all-cause mortality was assessed by Cox proportional hazards analysis.
Results
During a mean (±SD) follow-up of 7.5±4.5 years, a total of 1571 (23%) patients died. In a multivariate analysis including clinical, risk factor, and exercise test data, higher BMI was associated with better survival. Expressing the data by BMI category, obese patients were 22% less likely to die (relative risk [RR]=0.78, 95% confidence interval [CI], 0.69-0.90, P<.001) than patients of normal weight. After further adjustment for cardiorespiratory fitness (CRF), this relationship strengthened such that mortality risk for the obese category was 35% lower (RR=0.65, 95% CI, 0.57-0.76, P<.001), versus the normal weight category.
Conclusions
As has been observed in HF patients, obesity was associated with a substantially lower mortality risk in a clinical population of non-HF veterans. Higher CRF and obesity in later life may account for an obesity paradox in this population.
Cardiology Division, VA Palo Alto Health Care System/Stanford University, Palo Alto, Calif.
Requests for reprints should be addressed to Jonathan Myers, PhD, Cardiology Division, 111C, VA Palo Alto Health Care System, 3801 Miranda Ave., Palo Alto CA 94304.
ABSTRACT
