Because higher levels of adipose tissue are associated with inflammation, hypertension, insulin resistance, and dyslipidemia, the study authors theorized that, as the body mass ratios of study participants improved, their bodies became more efficient at extracting oxygen from the blood, and thus could better sustain physical activity.
Although there were few adverse events observed in the study, including acute shortness of breath in a member of the exercise-only group, Dr. Kitzman said in a JAMA podcast that, of some concern was that a third of the body mass lost by participants was muscle tissue. “That’s important because persons with heart failure have less-than-normal amounts of muscle tissue as part of their heart failure syndrome and as part of growing old. It could have adverse long-term consequences,” he said.
Dr. Kitzman said in an interview that he and his colleagues have decided next to focus on resistance training’s impact on VO2, after this study showed that overall muscle mass decreased mildly with diet, even with aerobic exercise. The new study will seek to establish a correlation between improved retention of skeletal muscle, strength, and overall function and resistance training combined with diet and aerobic exercise in HFpEF.
“We chose resistance training because it is known to increase skeletal muscle mass. On the other hand, resistance training can temporarily increase blood pressure and left ventricular afterload, which are already increased in HFpEF,” he said.
The net effect is that, at least for now, “resistance training in HFpEF should be formally tested before applying to patients,” Dr. Kitzman noted. The same is true, he added, for recommending dietary restrictions in HFpEF patients.
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