UCSF

Background

The 2018 US Physical Activity Guidelines recommend reducing sedentary behavior (SB) for cardiovascular health. SB's role in heart failure (HF) is unclear.

Methods

We studied 80 982 women in the Women's Health Initiative Observational Study, aged 50 to 79 years, who were without known HF and reported ability to walk ≥1 block unassisted at baseline. Mean follow-up was 9 years for physician-adjudicated incident HF hospitalization (1402 cases). SB was assessed repeatedly by questionnaire. Time-varying total SB was categorized according to awake time spent sitting or lying down (≤6.5, 6.6-9.5, >9.5 h/d); sitting time (≤4.5, 4.6-8.5, >8.5 h/d) was also evaluated. Hazard ratios and 95% CI were estimated using Cox regression.

Results

Controlling for age, race/ethnicity, education, income, smoking, alcohol, menopausal hormone therapy, and hysterectomy status, higher HF risk was observed across incremental tertiles of time-varying total SB (hazard ratios [95% CI], 1.00 [referent], 1.15 [1.01-1.31], 1.42 [1.25-1.61], trend P<0.001) and sitting time (1.00 [referent], 1.14 [1.01-1.28], 1.54 [1.34-1.78], trend P<0.001). The inverse trends remained significant after further controlling for comorbidities including time-varying myocardial infarction and coronary revascularization (hazard ratios: SB, 1.00, 1.11, 1.27; sitting, 1.00, 1.09, 1.37, trend P<0.001 each) and for baseline physical activity (hazard ratios: SB 1.00, 1.10, 1.24; sitting 1.00, 1.08, 1.33, trend P<0.001 each). Associations with SB exposures were not different according to categories of baseline age, race/ethnicity, body mass index, physical activity, physical functioning, diabetes, hypertension, or coronary heart disease.

Conclusions

SB was associated with increased risk of incident HF hospitalization in postmenopausal women. Targeted efforts to reduce SB could enhance HF prevention in later life.