To characterize physical activity (PA) in individuals with rheumatoid arthritis (RA) and to determine the associations between PA participation at light to moderate intensities and cardiovascular disease risk factors, disability, and disease activity.
The cross-sectional study used data from 2 RA cohorts. PA was measured using an accelerometry-based activity monitor, recording minutes/day spent in sedentary (≤1 metabolic equivalent [MET]), very light (1.1-1.9 METs), light (2-2.9 METs), and moderate activities (≥3 METs). Cardiovascular markers included body mass index, blood pressure, insulin resistance, and lipid profile. Disability and disease activity were measured using the Health Assessment Questionnaire (HAQ) and the Disease Activity Score in 28 joints (DAS28), respectively. Associations between PA at each intensity level and health markers were assessed by multiple linear regression models, adjusted for age, sex, and cohort.
Ninety-eight subjects (mean ± SD age 58 ± 9 years, 85% female) were included. Subjects spent 9.8 hours/day being sedentary, 3.5 hours/day engaged in very light PA, 2.1 hours/day engaged in light PA, and 35 minutes/day engaged in moderate PA. Only 17% were physically active (≥150 minutes/week of moderate PA in 10-minute bouts). Regression models showed that very light, light, and moderate PA were inversely associated with most cardiovascular disease risk factors and HAQ and DAS28 scores (R(2) Δ range 0.04-0.52, P < 0.05). The associations between PA and cardiovascular disease markers were either equivalent or stronger at very light and light intensities, as compared to moderate intensity.
Individuals with RA are mostly active at very light and light intensities. PA at these intensity levels associates favorably with cardiovascular markers and lower disability and disease activity in RA.