From the Journals

Exercise improves outcomes for patients with heart failure and OSA



Exercise may be as effective as CPAP in improving obstructive sleep apnea and quality of life in patients with heart failure, according to a study published in the October issue of Chest [].

Researchers undertook a randomized, four-arm trial in 65 patients with heart failure and obstructive sleep apnea, which compared the effects of CPAP alone, exercise alone – consisting of three supervised sessions per week for three months, or CPAP plus exercise. A control group received education sessions on the importance of exercise.

The greatest reduction in mean apnea-hypopnea index was seen in the CPAP group, who experienced a mean decrease of 24 events per hour. The exercise plus CPAP group and the exercise only groups showed a mean decrease of 10 events per hour. In contrast, the control group showed no significant decrease in the number of events per hour of sleep.

The authors commented that the change in apnea-hypopnea index was due to reduction in obstructive apneas and hypopneas, and noted the “difficulty of accurately distinguishing obstructive from central hypopneas”.

All the active interventions were associated with significant decreases in arousal index and improvements in sleep-related saturation compared to the control intervention.

Exercise – both alone and with CPAP – was associated with an increase in maximum heart rate and peak VO2, and decrease in VE/VCO2 slope compared to the CPAP-alone and control groups.

“We found that peak oxygen consumption and muscle performance improved significantly only in the exercise groups, but not with CPAP alone, even though CPAP was most effective in attenuating OSA severity,” wrote Dr. Denise M. Servantes, from the Departamento de Psicobiologia at the Universidade Federal de São Paul in Brazil, and co-authors. “Because peak VO2 is an independent predictor of survival and crucial to the optimal timing of cardiac transplantation, these findings have important clinical implications, even in patients who are adherent to CPAP.”

A significant number of participants in the active intervention groups changed New York Heart Association functional class; the number of patients in the exercise group in class I went from 0%-88% by three months, in the CPAP group it increased from 0% to 47%, and in the CPAP plus exercise group, it increased from 0% to 73%.

The study also found evidence of a trend towards improved sexual function in the participants who undertook both exercise plus CPAP.

All patients in the intervention groups showed improvements in subjective daytime sleepiness and quality of life, although improvements in the Minnesota Living with Heart Failure Questionnaire and Short Form Health Survey (SF-36) were significant only in the two groups that did exercise.

“The data suggest that exercise could be a therapeutic option for patients with HF and OSA who refuse CPAP or are intolerant to it,” the authors wrote. “In this regard, a considerable number of patients with HF and OSA do not experience subjective excessive daytime sleepiness and consequently observe no immediate benefit from using CPAP, which could contribute to poor long-term adherence.”

Individuals in the exercise group showed a slight but significant weight reduction, and those who undertook the exercise program also showed significant improvements in muscle strength and endurance compared to the control group.

The authors commented that another study examining the impact of weight loss program in people with moderate to severe obstructive sleep apnea found weight loss only or combined interventions achieved benefits for C-reactive protein levels, insulin resistance, and serum triglyceride levels. But these benefits weren’t seen with CPAP alone.

“The results of that study, and the present one emphasize the importance of adjunctive therapy of OSA with weight loss and exercise when applicable.”

However they acknowledged that the short duration of the study, and small sample size were limitations, and that this was only a preliminary investigation.

No conflicts of interest were declared.

SOURCE: Servantes D et al. Chest, 2018; 154:808-817.

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