After a 20-week regimen that included an improved diet and/or an increased exercise regiment, obese, older adults with heart failure had an increase in exercise capacity, according to a randomized trial conducted at an urban academic medical center.
However, the regimen did not have a significant effect on quality of life.
Lead author Dalane W. Kitzman, MD, of the Wake Forest School of Medicine in Winston Salem, N.C., and colleagues published their results online in JAMA on Jan. 5.
The study included 100 participants who were at least 60 years old, had a body mass index of 30 kg/m2 or higher and stable heart failure with preserved ejection fraction. The researchers mentioned that heart failure with preserved ejection fraction primarily occurs in older women, is the most rapidly increasing form of heart failure and is associated with high rates of morbidity, mortality and healthcare expenditures. Patients with heart failure with preserved ejection fraction typically have comorbid conditions such as coronary disease, diabetes, atrial fibrillation and hyperlipidemia.
Participants were randomized to an exercise group, a diet plus exercise group and a control group. The exercise regimen consisted of one-hour supervised walking sessions three times per week and was based on each person’s exercise test results. The diet consisted of a hypocaloric diet prepared with by the Wake Forest University General Clinical Research Center’s metabolic kitchen and supervised by a registered dietician.
Participants in the control group voluntarily agreed to not change their diet or exercise routine during the 20 weeks. However, they received telephone calls every two weeks for staff to check on their progress.
The co-primary outcomes were peak oxygen consumption as measured as the averageof measures from the last 30 seconds during peak exercise and disease-specific quality of life as assessed using the Minnesota Living with Heart Failure questionnaire.
Of the 92 participants who completed the trial, 84 percent were adherent to the exercise regimen and 99 percent were adherent to the diet. The mean age was approximately 67 years old and approximately 80 percent of participants were women.
The researchers found that the diet and exercise regimens led to significant increases in peak oxygen consumption, although the regimens did not improve the quality of life.
Peak oxygen consumption increased by 1.2 mL/kg body mass/min with exercise, by 1.3 mL/kg body mass/min with diet and by 2.5 mL/kg body mass/min with the combination of exercise and diet.
Participants’ body weights decreased by 7 percent in the diet group, 3 percent in the exercise group, 10 percent in the exercise and diet group and 1 percent in the control group.
Nanette K. Wenger, MD, of the Emory University School of Medicine, Atlanta, wrote in an accompanying editorial that further investigation of the combination of exercise and diet interventions was worth evaluating in a community setting with longer follow-up.
“Whether nonprofessionally administered diet and nonmedically supervised exercise could safely attain similar benefit is uncertain but worthy of exploration,” Wenger wrote.
Wenger also suggested that researchers examine the effects human interactions and digital technologies such as smartphone applications have on guiding caloric restrictions as well as whether dietary provisions are financially feasible and acceptable.