The more time older women spent sitting or lying down, the more likely their risk of hospitalization for heart failure, based on data from more than 80,000 postmenopausal women.
The 2018 Physical Activity Guidelines show evidence of the impact of physical activity on reducing heart failure risk, but the association between activity, sedentary behavior (SB) and heart failure (HF) in older women in particular has not been well studied, wrote Michael J. LaMonte, PhD, MPH, of the State University of New York at Buffalo, and colleagues in a study published in Circulation: Heart Failure . “Given the high prevalence of prolonged sedentary time among U.S. adults aged 65 and older, among whom HF burden is substantial, understanding the role SB has in HF development is relevant to future HF prevention strategies,” the researchers wrote.
The researchers identified 80,982 women aged 50-79 years who were enrolled in the Women’s Health Initiative Observational Study, had no known HF, and could walk at least one block unassisted. The average follow-up period was 9 years, and a total of 1,402 women were hospitalized for heart failure during the period of time they were observed.
The time spent sedentary (combined sitting or lying down) was divided into tertiles of 6.5 hours or less, 6.6-9.5 hours, and more than 9.5 hours. Time spent sitting was divided into tertiles of 4.5 hours or less; 4.6-8.5 hours; and more than 8.5 hours.
Heart failure risk goes up with more down time
After controlling for multiple variables including age, race, education, income, smoking status alcohol use, menopausal hormone therapy, and hysterectomy status, the researchers found that patients in the second tertile for sedentary behavior had a significantly increased heart failure risk than patients in the first tertile for sedentary behavior. This risk was even greater for patients falling in the third tertile for sedentary behavior. Odds ratios were 1.00 (referent), 1.15, and 1.42 for the lowest to highest tertiles for total sedentary behavior, respectively, and 1.00 (referent), 1.14, and 1.54 for sitting ( P < .001 for both total sedentary behavior and sitting only).
The trends remained significant after controlling for comorbidities including MI and coronary revascularization, and the associations were similar among categories of women with additional HF risk factors, including body mass index, diabetes, hypertension, and coronary heart disease.
Notably, the association between hours spent sitting or lying down and HF risk persisted even in women who met recommended activity levels, the researchers wrote.
The study findings were limited by the use of self-reports and by the inability to evaluate SB patterns or SB and HF subtypes, the researchers noted. However, the results were strengthened by the large sample size, use of time-varying SB exposure, and extensive controlling, and the data support the risk of increased SB on adverse cardiovascular outcomes.
“Results of this study underscore the need for effective strategies to reduce daily SB time, in addition to increasing recreational physical activity, as part of population efforts for HF prevention,” they concluded.
Clinicians know the value of a physically active lifestyle for heart health, said lead author Dr. LaMonte in a statement accompanying the study’s release. “However, our study clearly shows that we also need to increase efforts to reduce daily sedentary time and encourage adults to frequently interrupt their sedentary time. This does not necessarily require an extended bout of physical activity; it might simply be standing up for 5 minutes or standing and moving one’s feet in place.