Too Much Sitting, Lying Down Could Increase Heart Failure Risk by 42% in Older Women

Michael LaMonte, PhD, MPH

A new analysis of data from the Women’s Health Initiative is offering further insight into the impact of increased sedentary behavior on heart failure risk in older women.

Results suggest women spending 9.5 hours or more sitting or lying down each day had a 42% higher risk of being hospitalized with heart failure than women who spent 6.5 hours or less engaged in sedentary behavior, underlining the importance of emphasizing physical activity in aging patients.

"For heart failure prevention, we need to promote taking frequent breaks from prolonged sitting or lying down, in addition to trying to achieve guideline levels of physical activity, such as those recommended by the American Heart Association," said lead investigator Michael LaMonte, PhD, MPH, research associate professor of epidemiology in the School of Public Health and Health Professions at the University at Buffalo, in a statement from the American Heart Association. "Very few studies have been published on sedentary time and heart failure risk, and even fewer have focused on older women in whom both sedentary behavior and heart failure are quite common."

With a knowledge gap related to associations of heart failure and sedentary behavior in older patient populations, LaMonte and a team of colleagues from institutions across the US designed their study with the aim of determining the impact of sedentary behaviors on heart failure risk in older women. Investigators designed their study as a prospective analysis of data from the Women’s Health Initiative, which contains data on more than nearly 90,000 postmenopausal women.

Eliminating women with heart failure at enrollment and those with the inability to walk one block without assistance, investigators identified a cohort of 80,982 women aged 50-79 years for inclusion in their analysis. Women included in the study were also required to have completed questionnaires, which included assessments of sedentary behavior, at baseline and years 3, 6, and 9.

Sedentary behavior was assessed using 2 questions. The first question assessed how many hours per day were spent sitting, including time at work, sitting at the table eating, driving or riding a car or bus, and sitting up watching TV or talking. The second question assessed how many hours per day were spent lying down or with their feet up, including time spent sleeping or trying to sleep at night, resting or napping, and lying down watching TV. Respondents were given 8 response options ranging from less than 4 hours to 16 or more hours per day.

The mean age of the study cohort was 63 years, 84.9% were White, 45% reported menopausal therapy use, and the mean reported time spent engaging in sedentary behavior per day was 7 hours. Investigators pointed out 11% of patients reported no recreational physical activity. A total of 1402 incident cases of heart failure hospitalization were observed over a mean follow-up of 9 years.

For the purpose of analysis, women were categorized according to sedentary time. These groups were defined as having less than 6.5, 6.6-9.5, or more than 9.5 hours per day of time spent sitting or lying down and, for additional analysis, as 4.5 or less, 4.6-8.5, or more than 8.5 hours per day spent sitting. Of note, the groups spending less than 6.5 hours per day sitting or lying down and those spending 4.5 or less hours per day sitting were used as reference groups.

When controlling for confounding factors, including age, race-ethnicity, education, income, smoking, alcohol, menopausal hormone therapy, and hysterectomy status, results of the analysis indicated heart failure risk increased across incremental trestles of total sedentary behavior ([6.6-9.5 hours: HR, 1.15; 95% CI, 1.01-1.31], [More than 9.5 hours: HR, 1.42; 95% CI, 1.25-1.61], P for trend <.001) and sitting time ([4.6-8.5 hours: HR, 1.14; 95% CI, 1.01-1.28], [More than 8.5 hours: HR, 1.54; 95% CI, 1.34-1.78], P for trend<.001) compared to reference groups.

Further analysis indicated these trends remained significant after adjusting for additional factors, such as time-varying myocardial infarction and coronary revascularization (Total sedentary behavior HRs, 1.00, 1.11, 1.27; sitting HRs, 1.00, 1.09, 1.37; trend P <.001 each) and for baseline physical activity (Total sedentary behavior HRs, 1.00, 1.10, 1.24; sitting HRs, 1.00, 1.08, 1.33; trend P <.001 each). Investigators pointed out associations with sedentary behavior exposures did not differ based on age, race-ethnicity, BMI, physical activity, physical functioning, diabetes, hypertension, or coronary heart disease.

"These findings are consistent with other studies confirming that people with more daily sedentary time are more likely to develop chronic health conditions such as diabetes, high blood pressure, heart attack, stroke and premature death from heart disease and other causes," LaMonte added.

This study, “Association of Sedentary Time and Incident Heart Failure Hospitalization in Postmenopausal Women,” was published in Circulation: Heart Failure.