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Background: Evidence that higher sedentary time is associated with higher risk for cardiovascular disease (CVD) is based mainly on self-reported measures. Few studies have examined whether patterns of sedentary time are associated with higher risk for CVD.Methods: Women from the Objective Physical Activity and Cardiovascular Health (OPACH) Study (n=5638, aged 63-97, mean age=79±7) with no history of myocardial infarction (MI) or stroke wore accelerometers for 4-to-7 days and were followed for up to 4.9 years for CVD events. Average daily sedentary time and mean sedentary bout duration were the exposures of interest. Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for CVD using models adjusted for covariates and subsequently adjusted for potential mediators (body mass index (BMI), diabetes, hypertension, and CVD-risk biomarkers [fasting glucose, high-density lipoprotein, triglycerides, and systolic blood pressure]). Restricted cubic spline regression characterized dose-response relationships.Results: There were 545 CVD events during 19,350 person-years. Adjusting for covariates, women in the highest (≥ ~11 hr/day) vs. the lowest (≤ ~9 hr/day) quartile of sedentary time had higher risk for CVD (HR=1.62; CI=1.21-2.17; p-trend <0.001). Further adjustment for potential mediators attenuated but did not eliminate significance of these associations (p-trend<.05, each). Longer vs. shorter mean bout duration was associated with higher risks for CVD (HR=1.54; CI=1.27-2.02; p-trend=0.003) after adjustment for covariates. Additional adjustment for CVD-risk biomarkers attenuated associations resulting in a quartile 4 vs. quartile 1 HR=1.36; CI=1.01-1.83; p-trend=0.10). Dose-response associations of sedentary time and bout duration with CVD were linear (P-nonlinear >0.05, each). Women jointly classified as having high sedentary time and long bout durations had significantly higher risk for CVD (HR=1.34; CI=1.08-1.65) than women with both low sedentary time and short bout duration. All analyses were repeated for incident coronary heart disease (MI or CVD death) and associations were similar with notably stronger hazard ratios.Conclusions: Both high sedentary time and long mean bout durations were associated in a dose-response manner with increased CVD risk in older women, suggesting that efforts to reduce CVD burden may benefit from addressing either or both component(s) of sedentary behavior. [ABSTRACT FROM AUTHOR]

Background: Good lower extremity physical functioning is paramount to healthy aging as it prevents social isolation, enables civic engagement, and facilitates physical activity. Strong evidence links physical functioning with all-cause mortality, but little is known about its relationship to cardiovascular disease (CVD). Methods: Women (n=5043, mean age=79±7) with no history of myocardial infarction or stroke completed the Short Physical Performance Battery (SPPB) consisting of three timed tasks to assess standing balance, strength (5 chair stands), and gait (4m walk). Results were summarized using prespecified cutpoints yielding a score from 0 (worst) to 12 (best). Women were followed for CVD events for up to 6 years. Hazard ratios (HR) were estimated for women with poor, low, moderate, and high functioning (respective SPPB ranges for each group; 0-3, 4-6, 7-9, and 10-12) using Cox proportional hazard models adjusted for several covariates including accelerometer-measured moderate to vigorous physical activity (MVPA) and sedentary behavior. Effect modification of associations between SPPB and CVD by age, MVPA, Reynolds Risk Score, race-ethnicity, and self-rated health were tested by including multiplicative interaction terms in fully adjusted Cox models with statistical significance for interactions set to 0.10. Results: Covariate-adjusted HRs (95% CIs) for CVD [ 1.00 (ref.); 0.85 (0.62, 1.15); 0.69 (0.51, 0.93); 0.49 (0.35, 0.68)] and CVD mortality [ 1.00 (ref.); 0.72 (0.45, 1.15); 0.44 (0.27, 0.72); 0.35 (0.19, 0.62)] decreased across poor, low, moderate, and high SPPB subgroups, respectively (p-trend<.001 [ABSTRACT FROM AUTHOR]

Introduction: Experimental evidence suggests sedentary time (ST), in part, contributes to cardiovascular disease risk by eliciting detrimental hemodynamic changes (blood pooling, turbulent blood flow) in the lower limbs. However, few studies have examined the association of ST and peripheral artery disease (PAD). Hypothesis: We hypothesized that longer daily ST is associated with higher odds of PAD, independent of moderate-to-vigorous physical activity (MVPA). Methods: We examined cross-sectional associations of accelerometer-measured ST (measured over 7 days) and the ankle brachial index (ABI) among 7,677 Hispanic adults (ages 45-74) who were enrolled in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). ST (<100 counts/min) was standardized to 16 hours/d of wear time. Using multivariable logistic regression accounting for the complex survey design, we analyzed quartiles of ST then used restricted cubic splines (RCS) to assess non-linear associations of ST with odds of PAD (ABI ≤ 0.9), all models controlled for claudication, MVPA, and traditional cardiovascular risk factors. Results: Median ST was 12.2 hours/day (76% of wear time) and 366 (5%) participants had PAD. Using RCS with 3 knots (10th, 50th & 90th percentile), ST had a significant non-linear association with PAD (p= 0.004). As seen in the dose-response figure, a threshold effect was seen such that time spent above median ST was associated with significantly higher odds of PAD. For example, compared to median ST, 2 hours above median ST (14.2 hours/day) was associated with 1.60 times the odds of PAD (OR 1.60, 1.24-2.07). Conclusions: Among Hispanic/Latino adults, higher ST is associated with higher odds of PAD, independent of claudication, MVPA, and traditional cardiovascular risk factors. Importantly, this effect was only observed at higher levels of ST. Further study is warranted to determine if reducing high levels of ST may reduce risk of PAD or prevent progression of the disease. [ABSTRACT FROM AUTHOR]