Proportion and associated factors of meeting the 2018 Physical Activity Guidelines for Americans in adults with or at risk for knee osteoarthritis.

OBJECTIVES: Evaluate the prevalence of meeting the updated 2018 Physical Activity Guidelines for Americans (150 unbouted minutes in moderate-to-vigorous intensity physical activity [MVPA]) and determine cross-sectional factors associated with Guideline attainment in a community-based cohort of adults with or at elevated risk for knee osteoarthritis (OA). METHODS: Physical activity was monitored for 1 week in a subset of Osteoarthritis Initiative (OAI) participants with or at increased risk for knee OA. Accelerometer-measured weekly MVPA minutes were calculated; sociodemographic (age, sex, race, education, and working status) and health-related (body mass index [BMI], comorbidity, depressive symptoms, radiographic knee OA, and frequent knee symptoms) factors were assessed. We evaluated the prevalence of meeting 2018 Guidelines and used multivariate partial proportional odds model to identify factors associated with Guideline attainment, controlling for other factors in the model. RESULTS: Among 1922 participants (age 65.1 [standard deviation 9.1] years, BMI 28.4 [4.8] kg/m2, 55.2% women), 44.1% men and 22.2% women met the 2018 PA Guidelines. Adjusted cross-sectional factors associated with not-meeting 2018 Guidelines were: women, older age, higher BMI, non-Whites, depressive symptoms, not working, and frequent knee symptoms. CONCLUSION: In community-recruited adults with or at high risk for knee OA, more than 50% of men and nearly 80% of women failed to achieve the 2018 recommended level of at least 150 weekly unbouted minutes of MVPA. Study findings support gender and racial disparity in Guideline attainment and suggest addressing potentially modifiable factors (e.g., BMI, depressive symptoms, and frequent knee symptoms) to optimize benefits in PA-promoting interventions.

Reallocating time spent in sleep, sedentary behavior and physical activity and its association with pain: a pilot sleep study from the Osteoarthritis Initiative.

OBJECTIVE: Being physically active has broad health benefits for people with osteoarthritis (OA), including pain relief. Increasing physical activity (PA) requires reducing time in other behaviors within a fixed 24-h day. We examined the potential benefits in relation to pain from trading time in one type of wake or sleep behavior for another. METHOD: In this cross-sectional study, we used isotemporal logistic regression models to examine the estimated effect on pain from replacing time in one behavior with equal time in another, controlling for sociodemographic and health factors. Stratified analysis was conducted by the report of restless sleep. Sleep and wake behaviors [sedentary behavior (SB), light PA, moderate PA] were monitored by accelerometer in a pilot study of 185 Osteoarthritis Initiative (OAI) participants. Outcomes were bodily pain interference and knee pain. RESULTS: Moderate PA substituted for an equivalent time in sleep or other types of wake behaviors was most strongly associated with lower odds of pain (bodily pain interference odds reduced 21-25%, knee pain odds reduced 17-20% per 10-min exchange). These beneficial associations were particularly pronounced in individuals without restless sleep, but not in those with restless sleep, especially for bodily pain interference. CONCLUSION: Interventions promoting moderate physical activities may be most beneficial to address pain among people with or at high risk for knee OA. In addition to encouraging moderate-intensity PA, pain management strategies may also include the identification and treatment of sleep problems.

Sedentary behavior and blood pressure control among osteoarthritis initiative participants.

OBJECTIVE: To examine the association between sedentary behavior and blood pressure (BP) among Osteoarthritis Initiative (OAI) participants. DESIGN: We conducted a cross-sectional analysis of the OAI 48-month visit participants whose physical activity was measured using accelerometers. Participants were classified into four quartiles according to the percentage of wear time that was sedentary (<100 activity counts per min). Users of antihypertensive medications or non-steroidal anti-inflammatory drugs (NSAIDs) were excluded. Our main outcomes were systolic and diastolic blood pressures (SBP and DBP) and "elevated BP" defined as BP ≥ 130/85 mm Hg. RESULTS: For this study cohort (N = 707), mean BP was 121.4 ± 15.6/74.7 ± 9.5 mm Hg and 33% had elevated BP. SBP had a graded association with increased sedentary time (P for trend = 0.02). The most sedentary quartile had 4.26 mm Hg higher SBP (95% confidence interval (CI), 0.69-7.82; P = 0.02) than the least sedentary quartile, adjusting for age, moderate-to-vigorous (MV) physical activity, and other demographic and health factors. The probability of having elevated BP significantly increased in higher sedentary quartiles (P for trend = 0.046). There were no significant findings for DBP. CONCLUSION: A strong graded association was demonstrated between sedentary behavior and increased SBP and elevated BP, independent of time spent in MV physical activity. Reducing daily sedentary time may lead to improvement in BP and reduction in cardiovascular risk.