Background/Purpose: Rheumatoid Arthritis (RA) can result in functional disability and is associated with an increased risk of cardiovascular disease (CVD). In healthy adults and patient populations, light physical activity (LPA) engagement is reported to confer benefits to cardiovascular health and physical function, with time spent sedentary (i.e., activities ≤ 1.5 METS whilst sitting/lying) demonstrated to be adversely related to these health outcomes. Studies also indicate the manner in which sedentary time is accumulated (i.e., sedentary time, bouts, breaks) to hold implications for CVD profile and physical function. However, it is not known whether sedentary behaviour patterns and LPA are relevant to CVD risk and functional ability in RA. The aims of this study were therefore to investigate relationships between objectively assessed sedentary behaviour patterns and LPA with (1) 10-year risk of CVD, and (2) individual CVD risk factors and functional disability in RA. A secondary aim was to determine if associations were independent of moderate-to-vigorous physical activity (MVPA) engagement.

Methods: Patients with RA (N = 61) provided a fasted blood sample and underwent physical assessments to evaluate factors associated with their cardiovascular health. Ten-year CVD risk was computed via the Q-risk-score. Individual CVD risk factors were determined from fasted blood samples (Table 1), and functional disability assessed via the Stanford Health Assessment Questionnaire (HAQ). Sedentary behaviour patterns, LPA and MVPA were measured via 7-days of accelerometry. Sedentary time, LPA and MVPA (min/day) were defined as <100, 100 – 2019, and ≥2020 counts per minute, respectively. Sedentary breaks (number/day) were calculated as interruptions in sedentary time for ≥1 minute. Sedentary bout variables (number/day, average length) were derived by determining the number and length of consecutive zeros recorded above a ≥20 zero-count threshold.

Results: Regressions analyses were conducted to answer study aims. Models were adjusted as appropriate for age, gender and accelerometer-wear time (Model 1).  Where significant associations were observed, models were further adjusted for daily MVPA engagement (Model 2). Results revealed significant positive associations between sedentary time and the number of sedentary bouts per day ≥20 minutes with 10-year CVD risk, with the reverse true for LPA participation (model 1; sedentary time, β = .38, p <.01, sedentary bouts, β = .37, p <.01, LPA, β = −.45, p <.01). Associations were independent of MVPA engagement (model 2; β change = .01 to .03). Sedentary behaviour patterns and LPA were not related to individual CVD risk factors or functional disability.

Conclusion: Promoting LPA participation and restricting sedentary time to bouts <20 minutes may attenuate long-term CVD risk in RA, independent of MVPA engagement.