Author + information
- Published online September 5, 2018.
- aFondation Leducq, Paris, France
- bDivision of Cardiovascular Medicine, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
- ↵∗Address for correspondence:
Dr. Mariell Jessup, Leducq/Broadview, 265 Franklin Street, Suite 1902, Boston, Massachusetts 02110.
In 2008, the U.S. Department of Health and Human Services released Physical Activity Guidelines for Americans (1), the first comprehensive physical activity guidelines ever published by the federal government. These guidelines touted “substantial” health benefits from at least 150 min per week of moderate intensity or 75 min per week of vigorous intensity aerobic activity, or an equivalent combination of the 2 activities along with muscle-strengthening activity at least twice per week. These well-established benefits include risk reduction of coronary heart disease, stroke, hypertension, hyperlipidemia, and type 2 diabetes in both men and women (2). In addition to a reduction in cardiovascular morbidity, physical activity has been linked to a lower risk of all-cause mortality independent of socioeconomic and cardiovascular disease risk factors (3). Moreover, society major guidelines have been dedicated to addressing critical questions regarding the relationships among lifestyle behaviors, blood pressure, and lipid profile (2). Despite the recognition of physical inactivity as a significant and modifiable risk factor for coronary heart disease, contribution of inactivity to heart failure (HF) has been underemphasized.
It is anticipated that by 2030 more than 8 million people older than 18 years of age will be living with HF (2). The concurrent growth of the aging population and increasing prevalence of HF risk factors underscore the need to prioritize preventive strategies for this looming public health burden. Over the last decade, several studies have demonstrated inverse associations between physical activity and the risk of HF, but many of these studies did not discriminate outcomes by sex, race or ethnicity, or HF phenotype (4). As our understanding of the demographics and differences in HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) evolves, we must incorporate these nuances into evaluation and implementation of population-level interventions targeted at disease prevention.
In this issue of JACC: Heart Failure, LaMonte et al. (5) accepted this charge in their analysis of the association between recreational physical activity and HF in a particularly vulnerable and understudied populations: postmenopausal women of diverse racial-ethnic backgrounds. Previous longitudinal cohort studies demonstrated that the HF incidence rate in white women triples with each 10-year age increase between 65 and 74 and 75 and 84 years of age and that HF incidence, risk factor prevalence, and mortality rates are not uniform across ethnic groups (2). With this context, the authors examined the relationship between self-reported physical activity and incident HF in 137,303 community dwelling postmenopausal women from the Women’s Health Initiative, with a determination of HF subtype by clinical and echocardiographic parameter adjudication in 35,272 subjects (26%) of these participants. Recreational physical activity intensity (computed by frequency, duration, and strenuousness) and walking habits and speed were assessed at baseline and reported as metabolic equivalent of task(s) (METs) intensity values multiplied by the hours per week of reported participation (METs h/week). Total physical activity at baseline was the primary exposure, with additional modeling by tertiles of physical activity intensities and by walking separately. In contrast to previous studies that evaluated physical activity and incidence of HFpEF and HFrEF, this study demonstrates a clear inverse association for total physical activity and walking with the incidence of overall HF and of both HF subtypes (6).
Can we use this to support physical activity prescription in all older women? A closer look at the data suggests some caveats. The authors note that their multivariate models were computed with increasing control for confounding factors and then included potential HF mediators; the model selection strategies for standard risk factor adjustment are not articulated. Furthermore, the authors do 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. This has potential implications for the external validity of the findings. The authors acknowledge other study limitations include omission of additional potential mediating factors such as interim atrial fibrillation, diabetes, hypertension, and lack of a direct measurement of cardiorespiratory fitness, which is a stronger predictor of adverse cardiovascular outcomes than conventional risk factors (2).
Notwithstanding, the authors conducted a clever secondary analysis using time-varying physical activity levels to account for the possibility that changes in physical activity levels after baseline assessment could influence HF occurrence separately; doing so mitigated the inevitable bias due to exposure misclassification in studies of self-reported physical activity. Prior findings of a dose-dependent relationship between physical activity and incident HF are corroborated in the secondary analysis, with a higher risk reduction for overall HF and HFpEF observed in the highest total physical activity tertile compared to that at baseline, but this risk reduction is attenuated for HFrEF (4). In their multivariate-adjusted models, the authors attempted to isolate the effect on HF subtype of each physical activity type (mild, moderate, strenuous) at successive levels of physical activity (measured by MET h/week) but were only able to correlate >17.0 MET h/week of strenuous activity with a risk reduction in HFpEF. Interestingly, greater walking was significantly associated with lower risks of all 3 HF endpoints at baseline and in the time-varying analysis after controlling for other physical activity types. This risk reduction in incident HFpEF is certainly noteworthy as white women comprised the majority of patients who were hospitalized for HFpEF (59%), according to 2011 to 2014 data from the National Health and Nutrition Examination Survey (2). For older women who seem destined to develop HFpEF, physical activity could be the first and only prescription they need (Figure 1, pictorial representation of these findings).
In a large systematic review, Franco et al. (7) identified 6 major themes regarding barriers to physical activity in people ≥60 years of age: social influences, physical limitations, competing priorities, access difficulties, perceived personal benefits, and motivation and beliefs regarding physical activity. True patient-centered cardiovascular health promotion efforts should combine evidence-based population approaches for increasing physical activity with targeted interventions to combat these barriers in older Americans (2). LaMonte et al. (5) have helped us understand the types of physical activity that may reduce incident HF in postmenopausal women, and their study supports a growing body of work that validates the potential of physical activity as a primary tool to prevent HF.
↵∗ Editorials published in Journal of the American College of Cardiology: Heart Failure reflect the views of the authors and do not necessarily represent the views of JACC: Heart Failure or the American College of Cardiology.
Dr. Reza is supported by the U.S. National Institutes of Health National Human Genome Research Institute and the Ruth L. Kirschstein institutional national research service T32 award T32 HG009495 in genomic medicine. Dr. Jessup has reported that he has no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation
- ↵Office of Disease Prevention and Health Promotion. Physical Activity Guidelines. July 2018. Available at: https://health.gov/paguidelines/. Accessed June 27, 2018.
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