Both Light Intensity and Moderate-to-Vigorous Physical Activity Measured by Accelerometry Are Favorably Associated With Cardiometabolic Risk Factors in Older Women: The Objective Physical Activity and Cardiovascular Health (OPACH) Study

Background-The relationship between light intensity physical activity (PA), which is common in older adults, and cardiovascular disease (CVD) risk factors is unclear. This study examined associations of accelerometer-measured PA intensity with CVD risk factors in older women of different race-ethnicities. Methods and Results-Cross-sectional analyses were conducted in 4832 women (mean age 78.9 years; 52.5% white, 30.5% black, 17.1% Hispanic) who were without known CVD and wore triaxial accelerometers a minimum of 4 of 7 days with >= 10 hours/d awake wear-time. Vector magnitude counts per 15-s epoch were used to define time spent in low light (19-225 counts/15 s), high light (226-518), and moderate-to-vigorous; >= 519) intensity PA. Fasting CVD biomarkers, resting blood pressure, waist girth, body mass index, and 10-year predicted CVD risk (Reynolds Risk Score) were measured. After adjusting for age, wear time, raceethnicity, and potential confounders, each PA measure was favorably associated with mean high-density lipoprotein, triglyceride, glucose, C-reactive protein, body mass index, waist girth, and Reynolds Risk Score (P<0.05, all). Associations with mean blood pressure, insulin, and total and low-density lipoprotein cholesterol were variable. A 30-minute/d increment in PA was associated, on average, with odds ratios for high predicted CVD risk (Reynolds Risk Score >= 20) of 0.96 (95% confidence interval, 0.92, 1.00), 0.88 (0.83, 0.94), and 0.85 (0.79, 0.91) for low light, high light, and moderate-to-vigorous, respectively, and remained significant with further mutual control for PA intensity. Conclusions-PA measured by accelerometry, including light intensity PA, was associated with lower CVD risk factor levels in race-ethnically diverse older women.