Sleep Disturbance Trajectories in Osteoarthritis.

BACKGROUND/OBJECTIVE: Sleep disturbance is common among adults with osteoarthritis (OA), but little is known about patterns over time. In this cohort study, we identified restless sleep trajectories and associated factors in adults with or at high risk for knee OA. METHODS: Longitudinal (2004-2014) restless sleep (≥3 nights/week) annual reports over 8 years from 4359 Osteoarthritis Initiative participants were analyzed. Group-based trajectory modeling identified heterogeneous temporal patterns. Logistic regression identified baseline health and behavioral predictors of trajectory membership. RESULTS: Four restless sleep trajectory groups were identified: good (69.7%, persistently low restless sleep probabilities), worsening (9.1%), improving (11.7%), and poor (9.5%, persistently high). Among 2 groups initially having low restless sleep prevalence, the worsening trajectory group had an increased likelihood of baseline cardiovascular disease (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.01-2.33), pulmonary disease (OR, 1.48; 95% CI, 1.07-2.05), lower physical activity (OR, 1.29; 95% CI, 1.03-1.61), knee pain (OR, 1.04; 95% CI, 1.00-1.07), depressive symptoms (OR, 1.03; 95% CI, 1.01-1.06), and a decreased likelihood of better mental health (OR, 0.97; 95% CI, 0.95-0.98) at baseline. Among 2 groups initially having high restless sleep prevalence, the poor group had an increased likelihood of baseline depressive symptoms (OR, 1.03; 95% CI, 1.00-1.05). CONCLUSIONS: Four trajectories of restless sleep over 8 years were identified using data collected from over 4000 older adults aged 45 to 79 years with or at higher risk for knee OA. The presence of depressive symptoms, less physical activity, knee pain, poor mental health, cardiovascular disease, or pulmonary disease was each associated with unfavorable trajectories.

Association Between Sedentary Time and Quality of Life From the Osteoarthritis Initiative: Who Might Benefit Most From Treatment?

OBJECTIVE: To investigate the relationship between sedentary behavior and quality-adjusted life years (QALYs) among participants in the Osteoarthritis Initiative. DESIGN: Longitudinal, observational design. SETTING: Osteoarthritis Initiative cohort. PARTICIPANTS: Individuals (N=1794) from a prospective, multicenter longitudinal cohort were classified into quantile groups based on average daily sedentary time (most sedentary, quartile 1 [Q1] ≥11.6h; 10.7h≤ Q2 <11.6h; 9.7h≤ Q3 <10.7h; least sedentary, Q4 <9.7h). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Individual QALYs were estimated over 2 years from the area under the curve of health-related utility scores derived from the Medical Outcomes Study 12-Item Short-Form Health Survey versus time. The relationship between baseline sedentary behavior and median 2-year QALYs was estimated using quantile regression adjusted for socioeconomic factors and body mass index. RESULTS: Lower QALYs over 2 years were more frequently found among the most sedentary (Q1, median 1.59), and QALYs increased as time spent in baseline sedentary behavior decreased (median QALYs for Q2, 1.64; Q3, 1.65; Q4, 1.65). The relationship of sedentary time and median QALY change was only significant for the most sedentary Q1 group, where an additional hour of sedentary behavior significantly reduced QALYs by -.072 (95% confidence interval, -.121 to -.020). CONCLUSIONS: Our findings suggest that individuals with the most extreme sedentary profiles may be vulnerable to additional losses of quality of life if they become more sedentary. Targeting these individuals to decrease sedentary behavior has the potential to be cost-effective.

Patients Less Likely to Lose Weight Following a Knee Replacement: Results From the Osteoarthritis Initiative.

BACKGROUND: Knee replacement typically results in reduced pain and improved function, but it is unclear if these improvements lead to weight loss. OBJECTIVE: The purpose of this study was to examine weight change patterns preoperatively and postoperatively among overweight/obese knee replacement patients. METHODS: The study evaluated 210 overweight/obese patients from the Osteoarthritis Initiative who underwent a knee replacement during an 8-year longitudinal study. Average annual weight changes during 1- to 2-year intervals prior to, including, and subsequent to knee replacement were categorized as loss (≥-2.5%), maintain (>-2.5% to <2.5%), and gain (≥2.5%). Weight changes across time intervals were compared using logistic regression with generalized estimating equations, adjusting for demographic, health, and knee factors. RESULTS: On average, patients lost -0.6 kg/y during the interval when the surgery was performed, but weight gain (0.9 kg/y) in the initial postoperative interval represented an overall net weight gain (0.3 kg/y) compared with presurgery. Continued weight gain (0.3 kg/y) was also seen among patients with additional follow-ups. Patients were significantly less likely to have a meaningful weight loss in the time interval immediately following the surgery compared with the interval in which the surgery took place (odds ratio, 0.37; 95% confidence interval, 0.18-0.79). CONCLUSIONS: Overweight and obese patients initially lost weight during the interval including knee replacement; however, they were less likely to lose more than 2.5% of their weight in the 1 to 2 years immediately after the surgery. Knee replacement patients may benefit from weight management interventions both preoperatively and postoperatively.

Do Inactive Older Adults Who Increase Physical Activity Experience Less Disability: Evidence From the Osteoarthritis Initiative.

BACKGROUND: Physical inactivity is a leading risk factor for developing disability. Although randomized clinical trials have demonstrated improving physical activity can reduce this risk in older adults with arthritis, these studies did not specifically evaluate inactive adults. OBJECTIVES: The aim of this study was to evaluate the relationship of changes in physical activity with disability changes among initially inactive adults with or at high risk of knee osteoarthritis from Osteoarthritis Initiative. METHODS: Inactive persons were identified at baseline based on the US Department of Health and Human Services classification (no [zero] 10-minute session of moderate-to-vigorous [MV] activity over 1 week) from objective accelerometer monitoring. Two years later, physical activity change status was classified as follows: (1) met Federal physical activity guidelines (≥150 MV minutes/week acquired in bouts ≥10 minutes), (2) insufficiently increased activity (some but <150 MV bout minutes/week), or (3) remained inactive. Disability at baseline and 2 years was assessed by Late Life Disability Instrument limitation and frequency scores. Multiple regression evaluated the relationship of physical activity change status with baseline-to-2-year changes in disability scores adjusting for socioeconomics, health factors, and baseline disability score. RESULTS: Increased physical activity showed a graded relationship with improved disability scores in Late Life Disability Instrument limitation (P < 0.001) and frequency scores (P = 0.027). While increasing MV activity to guideline levels showed the greatest reduction, even insufficiently increased physical activity was related to reduced disability. CONCLUSIONS: Findings support advice to increase MV physical activity to reduce disability among inactive adults with or at high risk of knee osteoarthritis, even when guidelines are not met.

Combined Effects of Sedentary Behavior and Moderate-to-Vigorous Physical Activity on Cardiovascular Health in Older, Community-Dwelling Latinos.

This study examined the combined effects of sedentary behavior and moderate-to-vigorous physical activity (MVPA) on cardiovascular health in older Latinos. In a cross-sectional sample of 147 older, community-dwelling Latinos, time spent in sedentary behavior and MVPA were obtained using accelerometers. Analyses examined the effects of a measure of physical activity that combined levels of sedentary behavior (± 10 daily hours) and MVPA (< 30, 30-150, or > 150 weekly minutes) on cardiovascular health outcomes (blood pressure, BMI, waist circumference, cardiorespiratory fitness). Results suggest that cardiovascular health benefits of MVPA on BMI (p = .005), waist circumference (p = .002), and cardiorespiratory fitness (p = .012) may depend on a participant's level of sedentary behavior. For all three, health benefits of 30-150 weekly minutes of MVPA were found only for those without excessive sedentary behavior (≥ 10 hr). Sedentary behavior may negatively impact cardiovascular health despite moderate participation in MVPA. Health guidelines should suggest reducing sedentary behavior while increasing MVPA.

Sedentary Behavior as a Risk Factor for Physical Frailty Independent of Moderate Activity: Results From the Osteoarthritis Initiative.

OBJECTIVES: This prospective longitudinal study investigated the association between baseline objectively measured sedentary time and 2-year onset of physical frailty. METHODS: We studied 1333 Osteoarthritis Initiative participants 55 to 83 years of age who were at risk for physical frailty, as assessed via low gait speed (< 0.6 m per second) or inability to perform a single chair stand. Baseline sedentary time was assessed through accelerometer monitoring. Hazard ratios (HRs) for physical frailty onset were estimated with discrete survival methods that controlled for moderate physical activity, sociodemographic characteristics, baseline gait and chair stand functioning, and health factors. RESULTS: The incidence of physical frailty in this high-risk group was 20.7 per 1000 person-years. Greater baseline sedentary time (adjusted HR = 1.36 per sedentary hour; 95% confidence interval [CI] = 1.02, 1.79) was significantly related to incident physical frailty after control for time spent in moderate-intensity activities and other covariates. CONCLUSIONS: Our prospective data demonstrated a strong relationship between daily sedentary time and development of physical frailty distinct from insufficient moderate activity. Interventions that promote reductions in sedentary behaviors in addition to increases in physical activity may help decrease physical frailty onset.

Accelerometer-monitored sedentary behavior and observed physical function loss.

OBJECTIVES: We examined whether objectively measured sedentary behavior is related to subsequent functional loss among community-dwelling adults with or at high risk for knee osteoarthritis. METHODS: We analyzed longitudinal data (2008-2012) from 1659 Osteoarthritis Initiative participants aged 49 to 83 years in 4 cities. Baseline sedentary time was assessed by accelerometer monitoring. Functional loss (gait speed and chair stand testing) was regressed on baseline sedentary time and covariates (baseline function; socioeconomics [age, gender, race/ethnicity, income, education], health factors [obesity, depression, comorbidities, knee symptoms, knee osteoarthritis severity, prior knee injury, other lower extremity pain, smoking], and moderate-to-vigorous activity). RESULTS: This cohort spent almost two thirds of their waking hours (average=9.8 h) in sedentary behaviors. Sedentary time was significantly positively associated with subsequent functional loss in both gait speed (-1.66 ft/min decrease per 10% increment sedentary percentage waking hours) and chair stand rate (-0.75 repetitions/min decrease), controlling for covariates. CONCLUSIONS: Being less sedentary was related to less future decline in function, independent of time spent in moderate-to-vigorous activity. Both limiting sedentary activities and promoting physical activity in adults with knee osteoarthritis may be important in maintaining function.

Physical activity levels and functional performance in the osteoarthritis initiative: a graded relationship.

OBJECTIVE: Physical activity improves function in adults with arthritis, but it is unknown if there is a graded relationship between physical activity and functional benefit. This study was undertaken to examine the cross-sectional and longitudinal relationship between self-reported physical activity and observed functional performance in adults with knee osteoarthritis (OA). METHODS: The Osteoarthritis Initiative cohort included 2,589 patients with knee OA (2,301 with longitudinal followup data) who were ages 45-79 years at baseline. Prospective annual functional performance was assessed for 2 years using timed 20-meter walk tests. We used linear regression to estimate differences across physical activity quartiles in subsequent function (baseline and 1-year activity predicts 1-year and 2-year function, respectively) adjusted for demographic factors (age, sex, race/ethnicity, education level, and marital status) and health factors (OA severity, knee symptoms, knee pain, knee injury, body mass index, comorbidity, depression, smoking, alcohol use, and other joint pain). RESULTS: Increasing physical activity levels had a significant graded relationship to functional performance. Adults in physical activity quartile groups from least active to most active had an average gait speed of 4.0, 4.2, 4.3, and 4.5 feet/second, respectively, at baseline (P for trend<0.001) and 4.0, 4.2, 4.3, and 4.5 feet/second, respectively, after 1 year (P for trend<0.001); increasing trends remained significant after adjusting for covariates. Findings were similar within sex and age groups. CONCLUSION: These prospective data indicate a consistent graded relationship between physical activity level and better performance in adults with knee OA. These findings support guidelines that encourage patients with arthritis who cannot attain minimum recommended physical activity to be as active as possible.

Objective physical activity measurement in the osteoarthritis initiative: Are guidelines being met?

OBJECTIVE: Osteoarthritis (OA) clinical practice guidelines identify a substantial therapeutic role for physical activity, but objective information about the physical activity of this population is lacking. The aim of this study was to objectively measure levels of physical activity in adults with knee OA and report the prevalence of meeting public health physical activity guidelines. METHODS: Cross-sectional accelerometry data from 1,111 adults with radiographic knee OA (49-84 years old) participating in the Osteoarthritis Initiative accelerometry monitoring ancillary study were assessed for meeting the aerobic component of the 2008 Physical Activity Guidelines for Americans (≥150 minutes/week moderate-to-vigorous-intensity activity lasting ≥10 minutes). Quantile regression was used to test median sex differences in physical activity levels. RESULTS: Aerobic physical activity guidelines were met by 12.9% of men and 7.7% of women with knee OA. A substantial proportion of men and women (40.1% and 56.5%, respectively) were inactive, having done no moderate-to-vigorous activity that lasted 10 minutes or more during the 7 days. Although men engaged in significantly more moderate-to-vigorous activity (average daily minutes 20.7 versus 12.3), they also spent more time in no or very-low-intensity activity than women (average daily minutes 608.2 versus 585.8). CONCLUSION: Despite substantial health benefits from physical activity, adults with knee OA were particularly inactive based on objective accelerometry monitoring. The proportions of men and women who met public health physical activity guidelines were substantially less than those previously reported based on self-reported activity in arthritis populations. These findings support intensified public health efforts to increase physical activity levels among people with knee OA.

Relationship Between Self-Reported Restless Sleep and Objectively Measured Physical Activity in Adults With Knee Osteoarthritis.

OBJECTIVE: Despite the numerous health benefits of physical activity, inactivity is endemic among adults with knee osteoarthritis (OA). Because sleep quality may be a target in order to improve physical activity behavior, we investigated the cross-sectional relationship between restless sleep and physical activity in participants with or at risk for knee OA. METHODS: We analyzed accelerometer-measured physical activity and clinical data of participants included in the Osteoarthritis Initiative (OAI). We used multiple regression analysis to evaluate physical activity for participants, who were grouped by the reported frequency of restless sleep, and adjusted for demographic and medical confounders. RESULTS: Of the 1,892 OAI participants for whom complete data were available, 300 participants (16%) reported restless sleep ≥3 days in the past week. Participants who reported restless sleep for much of the time (3-4 days/week) and most of the time (5-7 days/week) had 11.9% and 23.7% less weekly minutes of moderately vigorous activity, respectively, compared to participants who reported rarely restless sleep (<1 day/week) (P for trend 0.021). These differences persisted after accounting for age, sex, race, body mass index, medical comorbidity, and knee OA severity and pain (P for trend 0.023). Differences related to restless sleep were largely attenuated by the presence of high depressive symptoms and low energy levels. CONCLUSION: Poor sleep quality is associated with less physical activity in persons with or at risk for knee OA. Future studies are needed to determine the mechanisms of how poor sleep and physical activity are related, how energy and depression mediate these relationships, and whether interventions that improve sleep quality might result in increased physical activity.

The Relationship between Polypharmacy and Physical Activity in Those with or at Risk of Knee Osteoarthritis.

OBJECTIVES: Physical activity is associated with improved pain, functional status, and less disability in persons with knee osteoarthritis (KOA). Because polypharmacy is related to several adverse health outcomes in older persons, we hypothesized that it might also be associated with decreased physical activity in those with KOA. This study evaluates the relationship between the number of prescription medications and weekly moderate to vigorous physical activity (MVPA). DESIGN: We used hierarchical median quantile regression analysis to examine the cross-sectional association between the number of prescription medications taken in the past 30 days and the median objectively measured MVPA minutes controlling for demographic and clinical variables. SETTING: Four Osteoarthritis Initiative (OAI) recruitment centers in Providence, Rhode Island; Columbus, Ohio; Baltimore, Maryland; and Pittsburgh, Pennsylvania. PARTICIPANTS: Accelerometer monitoring occurred in 2,127 OAI participants. Of these, 1,889 participants had 4 or more days of valid physical activity monitoring data and complete medication/covariate data. Data were collected at the 48-month OAI follow-up visit (2008-2010). MEASUREMENTS: The outcome was weekly minutes of MVPA measured with an accelerometer. Number/type of prescribed medications and covariate data (age, sex, race/ethnicity, body mass index, presence of comorbidities, pain, depressive symptoms, and radiographic KOA severity) were taken from the public OAI database. Polypharmacy was defined as taking five or more prescribed medications. RESULTS: The prevalence of polypharmacy in the study population was 28.2%. Each additional prescription medication was related to a decrease of 3.6 minutes (95% confidence interval [CI] = -4.8 to -2.1) in median weekly MVPA minutes. Participants meeting the polypharmacy criterion exhibited a decrease of 12.6 minutes (95% CI = -21.2 to -4.7) in median weekly MVPA minutes compared with those not meeting the criterion. CONCLUSION: An increased number of prescription medications and polypharmacy are associated cross-sectionally with decreased MVPA in adults with KOA. Further study is necessary to establish the causal nature of this association.

Improving Orthopedic-Related Postoperative Edema Management in a Rehabilitative Nursing Setting.

PURPOSE: The aim of the study was to reduce postoperative edema in total knee and hip arthroplasty rehabilitation patients. DESIGN: A pre- and posttest design was used for this quality improvement project at a rehabilitation facility. METHODS: Staff and patient edema education was standardized. Staff pre- and posttests were administered. Patients were interviewed to assess for knowledge of edema management. Chart audits were assessed for edema management and length of stay. FINDINGS: Average staff knowledge scores (n = 50) increased pre- to posteducational video (64% vs. 70%). Of patients interviewed posteducation (n = 24), 38% were able to list two characteristics of edema. Two chart audits completed pre- and posteducation demonstrated that the majority of patients (n = 30 per group) had edema upon admission (96% vs. 97%). However, length of stay decreased by 3 days (19.2 vs. 16.3). CONCLUSION: Standardized postoperative edema education can improve staff and patient edema knowledge and management. CLINICAL RELEVANCE: Edema education is recommended for orthopedic patients in rehabilitation facilities.

One Hour a Week: Moving to Prevent Disability in Adults With Lower Extremity Joint Symptoms.

INTRODUCTION: Physical activity guidelines recommend minimum thresholds. This study sought to identify evidence-based thresholds to maintain disability-free status over 4years among adults with lower extremity joint symptoms. METHODS: Prospective multisite Osteoarthritis Initiative accelerometer monitoring cohort data from September 2008 through December 2014 were analyzed. Adults (n=1,564) aged ≥49years at elevated disability risk because of lower extremity joint symptoms were analyzed for biennial assessments of disability-free status from gait speed ≥1meter/second (mobility disability-free) and self-report of no limitations in activities of daily living (activities of daily living disability-free). Classification tree analyses conducted in 2017-2018 identified optimal thresholds across candidate activity intensities (sedentary, light, moderate-vigorous, total light and moderate-vigorous activity, and moderate-vigorous accrued in bouts lasting ≥10 minutes). RESULTS: Minimal thresholds of 56 and 55 moderate-vigorous minutes/week best predicted disability-free status over 4years from mobility and activities of daily living disabilities, respectively, across the candidate measures. Thresholds were consistent across sex, BMI, age, and knee osteoarthritis presence. Mobility disability onset was one eighth as frequent (3% vs 24%, RR=0.14, 95% CI=0.09, 0.20) and activities of daily living disability onset was almost half (12% vs 23%, RR=0.55, 95% CI=0.44, 0.70) among people above versus below the minimum threshold. CONCLUSIONS: Attaining an evidence-based threshold of approximately 1-hour moderate-vigorous activity/week significantly increased the likelihood of maintaining disability-free status over 4years. This minimum threshold tied to maintaining independent living abilities has value as an intermediate goal to motivate adults to take action towards the many health benefits of a physically active lifestyle.

A randomized trial of a motivational interviewing intervention to increase lifestyle physical activity and improve self-reported function in adults with arthritis.

BACKGROUND: Arthritis is a leading cause of chronic pain and functional limitations. Exercise is beneficial for improving strength and function and decreasing pain. We evaluated the effect of a motivational interviewing-based lifestyle physical activity intervention on self-reported physical function in adults with knee osteoarthritis (KOA) or rheumatoid arthritis (RA). METHODS: Participants were randomized to intervention or control. Control participants received a brief physician recommendation to increase physical activity to meet national guidelines. Intervention participants received the same brief baseline physician recommendation in addition to motivational interviewing sessions at baseline, 3, 6, and 12 months. These sessions focused on facilitating individualized lifestyle physical activity goal setting. The primary outcome was change in self-reported physical function. Secondary outcomes were self-reported pain and accelerometer-measured physical activity. Self-reported KOA outcomes were evaluated by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for KOA (WOMAC scores range from 0 to 68 for function and 0 to 20 for pain) and the Health Assessment Questionnaire (HAQ) for RA. Outcomes were measured at baseline, 3, 6, 12, and 24 months. Multiple regression accounting for repeated measures was used to evaluate the overall intervention effect on outcomes controlling for baseline values. RESULTS: Participants included 155 adults with KOA (76 intervention and 79 control) and 185 adults with RA (93 intervention and 92 control). Among KOA participants, WOMAC physical function improvement was greater in the intervention group compared to the control group [difference = 2.21 (95% CI: 0.01, 4.41)]. WOMAC pain improvement was greater in the intervention group compared to the control group [difference = 0.70 (95% CI: -0.004, 1.41)]. There were no significant changes in physical activity. Among RA participants, no significant intervention effects were found. CONCLUSION: Participants with KOA receiving the lifestyle intervention experienced modest improvement in self-reported function and a trend toward improved pain compared to controls. There was no intervention effect for RA participants. Further refinement of this intervention is needed for more robust improvement in function, pain, and physical activity.

Physical Activity Minimum Threshold Predicting Improved Function in Adults With Lower-Extremity Symptoms.

OBJECTIVE: To identify an evidence-based minimum physical activity threshold to predict improved or sustained high function for adults with lower-extremity joint symptoms. METHODS: Prospective multisite data from 1,629 adults, age ≥49 years with symptomatic lower-extremity joint pain/aching/stiffness, participating in the Osteoarthritis Initiative accelerometer monitoring substudy were clinically assessed 2 years apart. Improved/high function in 2-year gait speed and patient-reported outcomes (PROs) were based on improving or remaining in the best (i.e., maintaining high) function quintile compared to baseline status. Optimal thresholds predicting improved/high function were investigated using classification trees for the legacy federal guideline metric requiring 150 minutes/week of moderate-vigorous (MV) activity in bouts lasting 10 minutes or more (MV-bout) and other metrics (total MV, sedentary, light intensity activity, nonsedentary minutes/week). RESULTS: Optimal thresholds based on total MV minutes/week predicted improved/high function outcomes more strongly than the legacy or other investigated metrics. Meeting the 45 total MV minutes/week threshold had increased relative risk (RR) for improved/high function (gait speed RR 1.8, 95% confidence interval [95% CI] 1.6, 2.1 and PRO physical function RR 1.4, 95% CI 1.3, 1.6) compared to less active adults. Thresholds were consistent across sex, body mass index, knee osteoarthritis status, and age. CONCLUSION: These results supported a physical activity minimum threshold of 45 total MV minutes/week to promote improved or sustained high function for adults with lower-extremity joint symptoms. This evidence-based threshold is less rigorous than federal guidelines (≥150 MV-bout minutes/week) and provides an intermediate goal towards the federal guideline for adults with lower-extremity symptoms.

Comparison of Subjective and Objective Measures of Sedentary Behavior Using the Yale Physical Activity Survey and Accelerometry in Patients With Rheumatoid Arthritis.

BACKGROUND: Sedentary behavior is associated with increased risk of functional decline and disability. Individuals with rheumatoid arthritis (RA) spend more time sedentary than healthy adults. Self-reported assessment of sedentary behavior has not been well-developed in this patient population. METHODS: 172 adults with RA wore an accelerometer for 7 days and completed a modified version of the Yale Physical Activity Survey (YPAS). YPAS-derived sedentary estimates included 1) daily sitting categories (<3, 3 to 6, 6 to 8, >8 hours/day), 2) continuous daily sedentary time calculated by subtracting hours spent sleeping or in physical activity from a 24-hour day, and 3) rank order of YPAS-derived continuous daily sedentary time. Each estimate was compared with objective accelerometer-derived sedentary time using linear regression and Bland-Altman analysis. RESULTS: A significant relationship was observed between accelerometer-derived sedentary time and all 3 estimates. Bland-Altman plot demonstrated systematic bias, however Bland-Altman plot of rank-order demonstrated that the ranked YPAS-derived continuous estimate was an unbiased predictor of ranked accelerometer sedentary time though limits of agreement were wide. CONCLUSIONS: This patient-reported approach using the YPAS shows promise to be a useful tool to identify the most sedentary patients. Providing a practical and accurate tool may increase the frequency sedentary behavior is assessed by clinicians.

Change in Physical Activity and Sedentary Time Associated With 2-Year Weight Loss in Obese Adults With Osteoarthritis.

BACKGROUND: We examined if changes in moderate-to-vigorous physical activity (MVPA), light activity, and sedentary behavior are related to weight change over a 2-year period in obese adults with/elevated risk for knee osteoarthritis. METHODS: Weight, physical activity, and sedentary time at baseline and 2 years were obtained from 459 obese participants from the Osteoarthritis Initiative. Weight change was categorized as ≥ 10 lbs, 5.0 to 9.9 lbs, 4.9 to -4.9 lbs, -5.0 to -9.9 lbs, and ≤ -10 lbs. We examined the association between 2-year weight change categories and changes in activity/sedentary time from accelerometer monitoring by multiple linear regression adjusted for baseline weight, demographic, and health factors. RESULTS: Across the 5 weight categories (loss to gain), average 2-year change ranged from -7.4 to 28.0 sedentary minutes/ day, 4.2 to -23.1 light activity minutes/day, and 3.2 to -4.9 MVPA minutes/day, respectively. Higher weight loss categories were separately associated with increased MVPA (P for trend < 0.001) and less sedentary gain (P for trend = 0.01). Weight loss categories had a strong trend with light activity gain but not statistically significant (P for trend = 0.06). CONCLUSIONS: Small increases in MVPA and decreases in sedentary time over 2 years were associated with weight loss among adults with obesity and with or at elevated risk for knee osteoarthritis.

Sedentary behavior and physical function: objective evidence from the Osteoarthritis Initiative.

OBJECTIVE: Investigate the relationship between sedentary behavior and physical function in adults with knee osteoarthritis (OA), controlling for moderate-vigorous physical activity (MVPA) levels. METHODS: Sedentary behavior was objectively measured by accelerometer on 1,168 participants ages 49-83 years in the Osteoarthritis Initiative with radiographic knee OA at the 48-month clinic visit. Physical function was assessed using 20-meter walk and chair stand testing. Sedentary behavior was identified by accelerometer activity counts/minute <100. The cross-sectional association between sedentary quartiles and physical function was examined by multiple linear regression, adjusting for demographic factors (age, sex, race/ethnicity, education level), health factors (comorbidity, body mass index, knee pain, knee OA severity, presence of knee symptoms), and average daily MVPA minutes. RESULTS: Adults with knee OA spent two-thirds of their daily time in sedentary behavior. The average gait speed among the most sedentary quartile was 3.88 feet/second, which was significantly slower than the speed of the less sedentary groups (4.23, 4.33, and 4.33 feet/second, respectively). The average chair stand rate among the most sedentary group was significantly lower (25.9 stands/minute) than the rates of the less sedentary behavior groups (28.9, 29.1, and 31.1 stands/minute, respectively). These trends remained significant in multivariable analyses adjusted for demographic factors, health factors, and average daily MVPA minutes. CONCLUSION: Being less sedentary was related to better physical function in adults with knee OA independent of MVPA time. These findings support guidelines to encourage adults with knee OA to decrease time spent in sedentary behavior in order to improve physical function.

Self-reported and objectively measured physical activity in adults with systemic lupus erythematosus.

OBJECTIVE: Most estimates of physical activity (PA) patterns in systemic lupus erythematosus (SLE) are based on subjective self-report measures prone to error. The aims of this study were to obtain objective measurements of PA using an accelerometer and estimates of energy expenditure based on the self-reported International Physical Activity Questionnaire (IPAQ), and to describe their relationship. METHODS: The Activity in Lupus To Energize and Renew study, a cross-sectional study of PA, included 129 persons with SLE. Accelerometer measures >7 days included total daily activity counts and minutes of moderate-vigorous PA (MVPA). Each person completed the IPAQ via telephone interview. Spearman's correlations (r) and 95% confidence intervals (95% CIs) assessed associations between accelerometer and IPAQ. RESULTS: Daily PA means and SDs from accelerometer measures were 502,910 ± 118,755 for total daily activity counts and 40 ± 30 minutes for MVPA. The median (interquartile range) MET minutes/day for IPAQ intensities were: 400 (159-693) for total; 83 (26-184) for walking; and 231 (77-514) for MVPA, and domains were: 0 (0-73) for work; 28 (0-85) for active transportation; 77 (26-231) for domestic and garden; and 57 (0-213) for leisure. Associations between accelerometer measures and IPAQ were 1) total daily count versus IPAQ total: r = 0.21 (95% CI 0.03, 0.37) and 2) MVPA versus IPAQ moderate-vigorous: r = 0.16 (95% CI - 230.02, 0.33). CONCLUSION: Accelerometer measures and IPAQ energy expenditure estimates were moderately correlated. IPAQ provided descriptive PA data, whereas accelerometers captured all daily activities, which can help assess guideline attainment. The choice of IPAQ versus accelerometer measure should include considering the purpose for which PA is measured.