Older women who were sedentary for long periods of time throughout the day had an increased risk for CVD, according to a study published in Circulation.
“Higher amounts of sedentary time and longer sedentary bouts were directly associated with cardiovascular disease,” John Bellettiere, PhD, postdoctoral scholar in the department of family medicine and public health at the University of California, San Diego, said in a press release. “Importantly, the association showed up regardless of a woman’s overall health, physical function and other cardiovascular risk factors, including whether they also were engaging in moderate to vigorous physical activity.”
OPACH study data
Researchers analyzed data from 5,638 women (mean age, 79 years) from the OPACH study without a history of stroke or MI. Women wore accelerometers for 24 hours a day for 7 consecutive days. Sleep logs were used to track when the women were in bed or out of bed.
The primary outcome of interest was CVD events, defined as the first occurrence of revascularization, MI, HF, hospitalized angina, CVD death or stroke. Another endpoint of interest was CHD events, which included coronary death or nonfatal MI. New CVD events were reported in an annual medical history update. Follow-up was conducted for up to 4.9 years.
During 19,350 person-years of follow-up, there were 545 CVD events and 137 CHD events.
Women who reported the highest sedentary time ( 11 hours a day) had a higher risk for CVD vs. those with the lowest sedentary time ( 9 hours a day) after adjusting for covariates (HR = 1.69; 95% CI, 1.27-2.26). The significance of these associations was not eliminated after further adjustment for potential mediators (P for trend < .05).
Women with longer mean bout durations had higher risks for CVD vs. those with shorter mean bout durations after adjusting for covariates (HR = 1.54; 95% CI, 1.27-2.02). After adjusting for CVD risk biomarkers, HRs were slightly weakened in quartile 4 (8.5-52.4 minutes of mean sedentary bout time) vs. quartile 1 (2.6-5.6 minutes of mean sedentary bout time; HR = 1.36; 95% CI, 1.01-1.83).
The dose-response associations between sedentary time and bout duration with CVD was linear (P-nonlinear > .05).
High sedentary times
Compared with women with low sedentary time and low bout duration, those with both high sedentary time and high bout duration had a significantly higher risk for CVD after adjusting for potential confounders (HR = 1.34; 95% CI, 1.08-1.65).
Similar associations were seen in analyses for incident CHD with stronger HRs.
“Sedentary behavior guidelines in several industrialized countries and recommendations from the American Diabetes Association call for an overall reduction in sedentary time and for regularly interrupting long sedentary bouts,” Bellettiere and colleagues wrote. “The results of this study, if replicated in other cohorts, support further consideration by U.S. public health entities of guidelines to reduce sedentary time and sedentary bout durations as part of an effort to lessen the personal and public health burden of CVD in our growing population of older adults.” – by Darlene Dobkowski
Disclosures: The OPACH study was funded by the NHLBI. The authors report no relevant financial disclosures.