Exercise Capacity and the Obesity Paradox in Heart Failure: The FIT (Henry Ford Exercise Testing) Project.
Mayo Clin Proc.
McAuley PA1, Keteyian SJ2, Brawner CA2, Dardari ZA3, Al Rifai M3, Ehrman JK2, Al-Mallah MH4, Whelton SP3, Blaha MJ3.
1 Department of Health, Physical Education and Sport Studies, Winston Salem State University, Winston Salem, NC. Electronic address: firstname.lastname@example.org.
2 Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, MI.
3 Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, MD.
4 Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins School of Medicine, Baltimore, MD; King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, King Abdulaziz Cardiac Center, Ministry of National Guard – Health Affairs, Riyadh, Kingdom of Saudi Arabia.
Year of Publication:
To assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies.
PATIENTS AND METHODS:
This large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models.
During a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively).
Maximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies.