— Lowest risk seen among those with highest levels of activity
Postmenopausal women who engaged in higher levels of exercise, even walking, were at lower risk for developing heart failure (HF), a new study found.
According to the observational analysis, women with increasing amounts of total physical activity -- measured in tertiles of metabolic equivalent (MET)-hours per week (>0-7.2, 7.3-17.0, and >17.0) -- had a reduced overall HF risk (HRs 0.89, 0.74, 0.65, trend P<0.001) compared to women who had no MET-hours per week of activity, reported Michael LaMonte, PhD, MPH, of the University at Buffalo in New York, and colleagues in JACC: Heart Failure.
These associations were seen both for HF patients with preserved ejection fraction (HFpEF; HRs 0.93, 0.70, 0.68, P<0.001) and HF patients with reduced ejection fraction (HFrEF; HRs 0.81, 0.59, 0.68, P=0.01).
The investigators also evaluated less rigorous forms of exercise like walking, which was also inversely tied to overall HF risk (HRs 0.98, 0.93, 0.72, P<0.001), HFpEF risk (HRs 0.98, 0.87, 0.67, P<0.001), and HFrEF risk (HRs 0.75, 0.78, 0.67, P=0.01) when compared with women who reported no MET-hours per week of walking.
"Our findings show clearly that higher amounts of self-reported total physical activity (assessed by questionnaire) are associated with significantly lower risks of developing overall heart failure and each subtype," LaMonte told MedPage Today. "We also show that walking, which is the most frequently reported leisure activity among older adults, confers similar benefits for reduced heart failure risks."
The study suggests "that how much physical activity you do matters more than doing physical activity at a certain effort or intensity level," Kelley Pettee Gabriel, PhD, of the University of Texas in Austin, explained to MedPage Today. "This is important for older adults who may only be able to participate in more gentle types of physical activity."
"These findings support the notion that it's never too late in life to become more physically active, and clinicians should encourage walking at any age," said Gabriel, who was not involved in the study.
But in an accompanying editorial
, Mariell Jessup, MD, chief science and medical officer of the American Heart Association, and Nosheen Reza, MD, of University of Pennsylvania in Philadelphia, cautioned that "a closer look at the data suggests some caveats" if attempting to use physical activity as a prescription for older women.
They pointed out that the "multivariable models were computed with increasing control for confounding and then included potential HF mediators; the model selection strategies for standard risk factor adjustment are not articulated."
Moreover, the investigators did not "present detailed output parameters from their models, making it difficult to understand the statistical and clinical significance of component covariates, or the overall degree to which the data are over or underfit," Jessup and Reza wrote.
The researchers assessed the exercise levels and prevalence of HF among 137,303 postmenopausal women (ages 50 to 79 years), and a subgroup consisting of 35,272 women where HFpEF and HFrEF were specifically reported. Over a 14-year follow up period, there were 2,523 HF cases in the larger cohort, and 451 HFrEF and 734 HFpEF cases in the smaller subgroup.
Comparing those who did not exercise versus those who did, the investigators found that the HF incidence (per 1,000 person-years) were as follows: 2.9 versus 1.8 for overall HF, 1.2 versus 0.8 for HFrEF, and 1.7 versus 1.3 for HFpEF.
LaMonte's group cited the self-reported exercise information as a limitation of their data set, and that the participants are not a true representation of the cross section of American women. And the subgroup analyses, they explained, were done on a smaller sample and so the results should be evaluated accordingly.
Other limitations highlighted by Jessup and Reza included "the omission of additional potential mediating factors such as interim atrial fibrillation, diabetes, hypertension, and the lack of a direct measure of cardiorespiratory fitness, which is a stronger predictor of adverse cardiovascular outcomes than traditional risk factors."
LaMonte and Gabriel did not report any disclosures.
The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, and U.S. Department of Health and Human Services.
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Read the original article on Medpage Today: Reduced Heart Failure Risk Among Active Elderly Women