Influence of Baseline Physical Activity Level on Exercise Training Response and Clinical Outcomes in Heart Failure: The HF-ACTION Trial

The role of physical activity on healthcare utilization in China

BACKGROUND

Evidence on the role of physical activity (PA) on healthcare utilization and expenditure is limited in China. We aimed to examine the association between the total physical activity (TPA) per week, healthcare service use and expenditure.

METHODS

We extracted the data from China Health and Retirement Longitudinal Study (CHARLS) 2011, 2013, and 2015. Participants more than 50 years old who completed the follow-up for the three waves were enrolled. We converted the volume of vigorous physical activity (VPA) into an equivalent volume of moderate physical activity (MPA) and calculated the TPA per week for each participant. 12,927 of the 17,708 participants in CHARLS were included in our analysis. More than one-third of participants over 50 years old never participate in any moderate or intensity activity, and the median of self-reported moderate or intensity PA was about 525 (IQR 0-1680) MET-minutes per week in 2015.

RESULTS

Compared to inactive subjects, the highest level of TPA was significantly related to the decreased risk number of inpatient visits (IRR: 0.58; 95% CI:0.50-0.67, p < 0.001), inpatient hospital days (IRR: 0.60; 95% CI: 0.42-0.84, p < 0.01), healthcare expenditure (IRR: 0.71; 95% CI: 0.65-0.79, p < 0.001) and catastrophic health expenditures (OR: 0.57; 95% CI: 0.45-0.72, p < 0.001) after adjusting for covariates.

CONCLUSIONS

Engaging in moderate-to-vigorous PA may drive a potential decrease in healthcare utilization, healthcare expenditure and household financial risk with a dose-response relationship in China, and some possible policy implications in public health may be considered to promote exercise in the middle-aged and elderly to reduce the medical burden on individuals and healthcare systems.

Physical activity and relationship to physical function, quality of life, and cognitive function in older patients with acute decompensated heart failure

BACKGROUND

Volitional physical activity level is predictive of a variety of health outcomes, but has not been examined in patients recently hospitalized for acute decompensated HF (ADHF).

METHODS

Ten to 14 days after index hospitalization for ADHF, 93 participants wore a wrist-mounted triaxial accelerometer (ActiGraph GT3X+) to objectively quantify sedentary behavior, light physical activity, and moderate-to-vigorous physical activity. Levels were compared to 2 groups of age-matched NHANES participants: healthy and chronic, stable HF. The relationship between physical activity levels and physical function [Short Physical Performance Battery (SPPB)], HF-specific quality-of-life (QOL) [Kansas City Cardiomyopathy Questionnaire (KCCQ)], and cognition [Montreal Cognitive Assessment (MOCA)] were examined.

RESULTS

ADHF participants accumulated a median 1,008 (IQR 896, 1,109) minutes of sedentary time, 88 (57, 139) minutes of light physical activity, and 10 (6, 25) minutes of moderate-to-vigorous physical activity per day. Sedentary time, light physical activity, or moderate-to-vigorous activity did not differ by sex or EF subtype. ADHF participants spent only 9% of awake time nonsedentary, compared to 34% and 27% for healthy adults and adults with chronic, stable HF, respectively. Among ADHF participants, SPPB, KCCQ, and MOCA scores did not differ among quartiles of total physical activity.

CONCLUSIONS

Older patients recently hospitalized for ADHF have very low levels of physical activity and high levels of sedentary time, both of which may be potential targets for interventions in this high-risk population. Physical activity level was not significantly associated with objectively measured physical function, QOL, or cognition, suggesting that this measure provides independent information regarding the patient experience of living with HF.

TRIAL REGISTRATION

NCT02196038, https://clinicaltrials.gov/ct2/show/NCT02196038.

Exercise-induced signaling pathways to counteracting cardiac apoptotic processes

Cardiovascular diseases are the most common cause of death in the world. One of the major causes of cardiac death is excessive apoptosis. However, multiple pathways through moderate exercise can reduce myocardial apoptosis. After moderate exercise, the expression of anti-apoptotic proteins such as IGF-1, IGF-1R, p-PI3K, p-Akt, ERK-1/2, SIRT3, PGC-1α, and Bcl-2 increases in the heart. While apoptotic proteins such as PTEN, PHLPP-1, GSK-3, JNK, P38MAPK, and FOXO are reduced in the heart. Exercise-induced mechanical stress activates the β and α5 integrins and subsequently, focal adhesion kinase phosphorylation activates the Akt/mTORC1 and ERK-1/2 pathways, leading to an anti-apoptotic response. One of the reasons for the decrease in exercise-induced apoptosis is the decrease in Fas-ligand protein, Fas-death receptor, TNF-α receptor, Fas-associated death domain (FADD), caspase-8, and caspase-3. In addition, after exercise mitochondrial-dependent apoptotic factors such as Bid, t-Bid, Bad, p-Bad, Bak, cytochrome c, and caspase-9 are reduced. These changes lead to a reduction in oxidative damage, a reduction in infarct size, a reduction in cardiac apoptosis, and an increase in myocardial function. After exercising in the heart, the levels of RhoA, ROCK1, Rac1, and ROCK2 decrease, while the levels of PKCε, PKCδ, and PKCɑ are activated to regulate calcium and prevent mPTP perforation. Exercise has an anti-apoptotic effect on heart failure by increasing the PKA-Akt-eNOS and FSTL1-USP10-Notch1 pathways, reducing the negative effects of CaMKIIδ, and increasing the calcineurin/NFAT pathway. Exercise plays a protective role in the heart by increasing HSP20, HSP27, HSP40, HSP70, HSP72, and HSP90 along with increasing JAK2 and STAT3 phosphorylation. However, research on exercise and factors such as Pim-1, Notch, and FAK in cardiac apoptosis is scarce, so further research is needed. Future research is recommended to discover more anti-apoptotic pathways. It is also recommended to study the synergistic effect of exercise with gene therapy, dietary supplements, and cell therapy for future research.

Outcomes With Multidisciplinary Cardiac Rehabilitation in Post-acute Systolic Heart Failure Patients-A Retrospective Propensity Score-Matched Study

Background

Cardiac rehabilitation (CR) is recommended for patients with acute heart failure (HF). However, the results of outcome studies and meta-analyses on CR in post-acute care are varied. We aimed to assess the medium- to long-term impact of CR and ascertain the predictors of successful CR.

Methods

In this propensity score-matched retrospective cohort study, records of consecutive patients who survived acute HF (left ventricular ejection fraction <40) and participated in a multidisciplinary HF rehabilitation program post-discharge between May 2014 and July 2019 were reviewed. Patients in the CR group had at least one exercise session within 3 months of discharge; the others were in the non-CR group. After propensity score matching, the primary (all-cause mortality) and secondary (HF readmission and life quality assessment) outcomes were analyzed.

Results

Among 792 patients, 142 attended at least one session of phase II CR. After propensity score matching for covariates related to HF prognosis, 518 patients were included in the study (CR group, 137 patients). The all-cause mortality rate was 24.9% and the HF rehospitalization rate was 34.6% in the median 3.04-year follow-up. Cox proportional hazard analysis revealed that the CR group had a significant reduction in all-cause mortality compared to the non-CR group (hazard ratio [HR]: 0.490, 95% confidence interval [CI]: 0.308-0.778). A lower risk of the primary outcome with CR was observed in patients on renin-angiotensin-aldosterone system (RAAS) inhibitors, but was not seen in patients who were not prescribed this class of medications (interaction p = 0.014).

Conclusions

Cardiac rehabilitation participation was associated with reduced all-cause mortality after acute systolic heart failure hospital discharge. Our finding that the benefit of CR was decreased in patients not prescribed RAAS inhibitors warrants further evaluation.

Vascular Function in Patients After Myocardial Infarction: The Importance of Physical Activity

Background: Patients after myocardial infarction have impaired vascular function. However, effects of lifestyle, e.g., physical activity level, on endothelial function and arterial stiffness remain scarce. The aim of our study was to investigate effects of physical activity level and risk factors on endothelial function and arterial stiffness.

Methods: In this cross-sectional study, we ultrasonographically assessed parameters of vascular function, namely flow mediated dilation (FMD) of the brachial artery and carotid artery stiffness in patients after myocardial infarction referred to the cardiac rehabilitation. The International Physical Activity Questionnaire (IPAQ) was obtained from all participants. Based on the IPAQ, patients were classified into three groups: vigorous, moderate, and low physical activity engagement. ANOVA was used for comparison among three groups using Bonferroni correction to determine differences between two sub-groups.

Results: One hundred and eight patients after myocardial infarction (mean age 53 ± 10 years) were included. There were significant differences in terms of FMD (8.2 vs. 4.2 vs. 1.9%, p < 0.001) and pulse wave velocity (PWV), a measure of arterial stiffness (6.1 vs. 6.4 vs. 6.9 m/s, p = 0.004) among groups of vigorous, moderate, and low physical activity engagement, respectively. However, in younger patients only FMD remained associated with physical activity level, while arterial stiffness was not. Low physical activity engagement was a significant predictor of both FMD and PWV in univariate and multivariate models, adjusted for age, sex, and other risk factors.

Conclusion: Low physical activity level is associated with impaired endothelial function and increased arterial stiffness in patients after myocardial infarction. Future studies are warranted to address this issue in a context of cardiac rehabilitation protocols optimization in order to improve vascular function in these patients.

Exercise: a molecular tool to boost muscle growth and mitochondrial performance in heart failure?

Impaired exercise capacity is the key symptom of heart failure (HF) and is associated with reduced quality of life and higher mortality rates. Unfortunately, current therapies, although generally lifesaving, have only small or marginal effects on exercise capacity. Specific strategies to alleviate exercise intolerance may improve quality of life, while possibly improving prognosis as well. There is overwhelming evidence that physical exercise improves performance in cardiac and skeletal muscles in health and disease. Unravelling the mechanistic underpinnings of exercise‐induced improvements in muscle function could provide targets that will allow us to boost exercise performance in HF. With the current review we discuss: (i) recently discovered signalling pathways that govern physiological muscle growth as well as mitochondrial quality control mechanisms that underlie metabolic adaptations to exercise; (ii) the mechanistic underpinnings of exercise intolerance in HF and the benefits of exercise in HF patients on molecular, functional and prognostic levels; and (iii) potential molecular therapeutics to improve exercise performance in HF. We propose that novel molecular therapies to boost adaptive muscle growth and mitochondrial quality control in HF should always be combined with some form of exercise training.

Prognostic score based on physical frailty in patients with heart failure: a multicenter prospective cohort study (FLAGSHIP)

BACKGROUND

In patients with heart failure (HF), physical frailty should be assessed to enable risk stratification. No conventional frailty criteria have so far been developed considering HF-specific outcomes. This study aimed to propose a frailty-based prognostic score using a nationwide cohort study of Japanese patients with HF.

METHODS

We analysed 2721 patients hospitalized for HF and capable of walking at discharge (median age: 76 years [interquartile range 67-83], men: 60.5%). Physical frailty was evaluated at discharge using four quantitative measures: usual walking speed, grip strength, Performance Measure for Activities of Daily Living-8 (PMADL-8), and Self-Efficacy for Walking-7 (SEW-7). The primary outcome was a composite of HF rehospitalization and all-cause mortality within 2 years. A cut-off point was identified for each measure using receiver operating characteristic analysis in a derivation cohort (n = 1778). Cox proportional hazards model was used to assign a score to each frailty domain according to the correlation with the endpoint. Patients were divided into four categories according to the sum score, and survival was compared by analysing the Kaplan-Meier curve and Cox proportional hazards model. Cumulative incidences of the events according to frailty categories were compared between the derivation cohort and a validation cohort (n = 943).

RESULTS

The cut-off value and assigned score of each indicator was determined as follows: usual walking speed < 0.98 m/s = 4 points; grip strength < 30.0 kg (men) or 17.5 kg (women) = 5 points; PMADL-8 ≥ 21 points = 2 points; SEW-7 ≤ 20 points = 3 points. We stratified patients into four categories according to the sum score: Category I, ≤3 points; Categories II, 4-8 points; Category III, 9-13 points; and Category IV, 14 points. The prevalence and cumulative incidence of the composite outcome for Categories I to IV in the derivation cohort were 27.4%, 25.2%, 26.4%, and 21.0%, and 9.5, 16.3, 26.3, and 36.8/100 person-years, respectively. Similar results were confirmed in the validation cohort. In Cox proportional hazards model, frailty categories were associated with the composite outcome independent of potential confounders (hazard ratio [95% confidence interval] in reference to Category I: Categories II, 1.51 [0.84-2.72], P = 0.169; Category III, 2.37 [1.32-4.23], P = 0.004; Category IV, 2.66 [1.45-4.89], P = 0.002).

CONCLUSIONS

The frailty-based prognostic score proposed in this study was well associated with prognosis and will serve for risk stratification in patients with HF.

Heart failure and promotion of physical activity before and after cardiac rehabilitation (HF-aPProACH): a study protocol

Aims

Lifestyle changes, such as increasing physical activity (PA), are a cornerstone of treatment of patients with chronic heart failure (HF). However, improving PA in HF patients is challenging, and low participation rates for cardiac rehabilitation (CR) as well as relapse to low PA levels after CR are major issues. We designed a randomized controlled trial to investigate if PA monitoring with motivational feedback before and after centre‐based CR in HF patients with reduced ejection fraction (HFrEF) will lead to a clinically meaningful increase in physical fitness.

Methods and results

A randomized controlled trial will be conducted in a sample of 180 HFrEF patients (New York Heart Association Class II/III) who are referred to 12‐week standard CR. Patients will be randomized (2:1) to (1) standard of care (SoC) plus wearing a PA monitoring device (Fitbit Charge 3) with personalized step goals, feedback and motivation or (2) SoC only. The intervention lasts ±7 months: 4–5 weeks before CR, 12 weeks during CR and 12 weeks after CR. Measurements will take place at three time points. The primary endpoint is the change in the distance in 6‐min walking test (6MWT) over the entire study period. Other endpoints include step count, grip strength, quality of life and all‐cause mortality or hospitalization.

Conclusions

HF‐aPProACH will provide novel information on the effectiveness of remote PA stimulation and feedback before, during and after standard CR using a commercially available device to improve physical fitness in HFrEF patients.

Establishing a cardiac training group for patients with heart failure: the "HIP-in-Würzburg" study

Background

Exercise training in heart failure (HF) is recommended but not routinely offered, because of logistic and safety-related reasons. In 2020, the German Society for Prevention&Rehabilitation and the German Society for Cardiology requested establishing dedicated “HF training groups.” Here, we aimed to implement and evaluate the feasibility and safety of one of the first HF training groups in Germany.

Methods

Twelve patients (three women) with symptomatic HF (NYHA class II/III) and an ejection fraction ≤ 45% participated and were offered weekly, physician-supervised exercise training for 1 year. Patients received a wrist-worn pedometer (M430 Polar) and underwent the following assessments at baseline and after 4, 8 and 12 months: cardiopulmonary exercise test, 6-min walk test, echocardiography (blinded reading), and quality of life assessment (Kansas City Cardiomyopathy Questionnaire, KCCQ).

Results

All patients (median age [quartiles] 64 [49; 64] years) completed the study and participated in 76% of the offered 36 training sessions. The pedometer was worn ≥ 1000 min per day over 86% of the time. No cardiovascular events occurred during training. Across 12 months, NT-proBNP dropped from 986 pg/ml [455; 1937] to 483 pg/ml [247; 2322], and LVEF increased from 36% [29;41] to 41% [32;46]%, (p for trend = 0.01). We observed no changes in exercise capacity except for a subtle increase in peak VO₂% predicted, from 66.5 [49; 77] to 67 [52; 78]; p for trend = 0.03. The physical function and social limitation domains of the KCCQ improved from 60 [54; 82] to 71 [58; 95, and from 63 [39; 83] to 78 [64; 92]; p for trend = 0.04 and = 0.01, respectively. Positive trends were further seen for the clinical and overall summary scores.

Conclusion

This pilot study showed that the implementation of a supervised HF-exercise program is feasible, safe, and has the potential to improve both quality of life and surrogate markers of HF severity. This first exercise experiment should facilitate the design of risk-adopted training programs for patients with HF.

Exercise training and high-sensitivity cardiac troponin T in patients with heart failure with reduced ejection fraction

AIMS

Whether an exercise training intervention is associated with reduction in long-term high-sensitivity cardiac troponin T (hs-cTnT) concentration (a biomarker of subclinical myocardial injury) in patients with heart failure with reduced ejection fraction (HFrEF) is unknown. The aims were to determine (i) the effect of a 12 week endurance exercise training intervention with different training intensities on hs-cTnT in stable patients with HFrEF (left ventricular ejection fraction ≤ 35%) and (ii) associations between hs-cTnT and peak oxygen uptake (VO2peak ).

METHODS AND RESULTS

In this sub-study of the SMARTEX-HF trial originally including 261 patients from nine European centres, 213 eligible patients were included after withdrawals and appropriate exclusions [19% women, mean age 61.2 years (standard deviation: 11.9)], randomized to high-intensity interval training (HIIT; n = 77), moderate continuous training (MCT; n = 63), or a recommendation of regular exercise (RRE; n = 73). Hs-cTnT measurements and clinical data acquired before (BL) and after a 12 week exercise training intervention (12 weeks) and at 1 year follow-up (1 year) were analysed using multivariable mixed models. Baseline hs-cTnT was above the 99th percentile upper reference limit of 14 ng/L in 35 (48%), 35 (56%), and 49 (64%) patients in the RRE, MCT, and HIIT groups, respectively. Median hs-cTnT was 16 ng/L at BL, 14 ng/L at 12 weeks, and 14 ng/L at 1 year. Hs-cTnT was statistically significantly reduced at 12 weeks in a model adjusted for randomization group, centre and VO2peak , and after further adjustment in the final model that also included age, sex, creatinine concentrations, N-terminal pro-brain natriuretic peptide, smoking, and heart failure treatment. The mean reduction from BL to 12 weeks in the final model was 1.1 ng/L (95% confidence interval: 1.0-1.2 ng/L, P < 0.001), and the reduction was maintained at 1 year with a mean reduction from BL to 1 year of 1.1 ng/L (95% confidence interval: 1.0-1.1 ng/L, P = 0.025). Randomization group was not associated with hs-cTnT at any time point (overall test: P = 0.20, MCT vs. RRE: P = 0.81, HIIT vs. RRE: P = 0.095, interaction time × randomization group: P = 0.88). Independent of time point, higher VO2peak correlated with lower hs-cTnT (mean reduction over all time points: 0.2 ng/L per increasing mL·kg-1 ·min-1 , P = 0.002), without between-group differences (P = 0.19).

CONCLUSIONS

In patients with stable HFrEF, a 12 week exercise intervention was associated with reduced hs-cTnT in all groups when adjusted for clinical variables. Higher VO2peak correlated with lower hs-cTnT, suggesting a positive long-term effect of increasing VO2peak on subclinical myocardial injury in HFrEF, independent of training programme.

Prognostic impact of muscle and fat mass in patients with heart failure

BACKGROUND

Cachexia, characterized by loss of muscle with or without loss of fat mass, is a poor prognostic factor in patients with heart failure (HF). However, there is limited investigation on the prognostic impact of muscle and fat mass separately in HF. We hypothesized that muscle and fat mass have different effects on the prognosis of HF.

METHODS

This was an observational cohort study of 418 patients (59% were men) admitted with a diagnosis of HF (71 ± 13 years [mean ± standard deviation]), with left ventricular ejection fraction (LVEF) of 39 ± 16%, including 31.3%, 14.8%, and 53.8% of patients with preserved LVEF (LVEF ≥ 50%), mid-range LVEF (40-50%), and reduced (<40%) LVEF, respectively. Dual-energy X-ray absorptiometry was performed with the patients in the stable state after decongestion therapy.

RESULTS

The mean body mass index of patients was 22.1 ± 4.6 kg/m² , and the mean appendicular skeletal mass (ASM) index was 6.88 ± 1.23 kg/m² in men and 5.59 ± 0.92 in women; 54.1% of the patients showed reduced muscle mass defined by the international cut-off value (7.0 kg/m² for men and 5.4 for women). The mean fat mass was 20.4 ± 7.2% in men and 27.2 ± 8.6% in women. During a median follow-up of 37 months, 92 (22.0%) of 418 patients with HF died (1 and 3 year mortality: 8.4% and 17.3%, respectively). Lower values of both skeletal muscle and fat mass were independently associated with increased risk of mortality adjusted for age, sex, haemoglobin, New York Heart Association functional class, and height squared (hazard ratio with 95% confidence interval of 0.825 [0.747-0.908] per 1 kg increase of ASM, P < 0.001, and 0.954 [0.916-0.993] per 1 kg increase of fat mass, P = 0.018, respectively).

CONCLUSIONS

More than half of the patients with HF showed reduced muscle mass. Lower values of both muscle and fat mass were associated with higher mortality in HF.

Targets identified from exercised heart: killing multiple birds with one stone

Cardiovascular diseases (CVDs) are a major cause of mortality worldwide, which are mainly driven by factors such as aging, sedentary lifestyle, and excess alcohol use. Exercise targets several molecules and protects hearts against many of these physiological and pathological stimuli. Accordingly, it is widely recognized as an effective therapeutic strategy for CVD. To investigate the molecular mechanism of exercise in cardiac protection, we identify and describe several crucial targets identified from exercised hearts. These targets include insulin-like growth factor 1 (IGF1)-phosphatidylinositol 3 phosphate kinase (PI3K)/protein kinase B (AKT), transcription factor CCAAT/enhancer-binding protein β (C/EBPβ), cardiac microRNAs (miRNAs, miR-222 and miR-17-3p etc.), exosomal-miRNAs (miR-342, miR-29, etc.), Sirtuin 1 (SIRT1), and nuclear factor erythroid 2‑related factor/metallothioneins (Nrf2/Mts). Targets identified from exercised hearts can alleviate injury via multiple avenues, including: (1) promoting cardiomyocyte proliferation; (2) facilitating cardiomyocyte growth and physiologic hypertrophy; (3) elevating the anti-apoptotic capacity of cardiomyocytes; (4) improving vascular endothelial function; (5) inhibiting pathological remodeling and fibrosis; (6) promoting extracellular vesicles (EVs) production and exosomal-molecules transfer. Exercise is one treatment (‘stone’), which is cardioprotective via multiple avenues (‘birds’), and is considered ‘killing multiple birds with one stone’ in this review. Further, we discuss the potential application of EV cargos in CVD treatment. We provide an outline of targets identified from the exercised heart and their mechanisms, as well as novel ideas for CVD treatment, which may provide novel direction for preclinical trials in cardiac rehabilitation.

Pre-injury activity predicts outcomes following distal radius fractures in patients age 60 and older

INTRODUCTION

One out of every 5 elderly patients will suffer a distal radius fracture and these injuries are often related to poor bone health. Several surgical subspecialties have demonstrated that pre-injury activity level can impact patient outcomes. To determine the importance of physical activity, we examined the relationship between pre-injury activity and patient-reported and functional outcomes among fracture patients.

METHODS

This is a retrospective analysis of prospectively collected data from participants enrolled in the Wrist and Radius Injury Surgical Trial (WRIST) from April 10, 2012 to December 31, 2016. This study included 304 adults, 60 years or older with isolated unstable distal radius fractures; 187 were randomized to one of three surgical treatments and 117 opted for casting. Participants opting for surgery were randomized to receive volar locking plate, percutaneous pinning, or external fixation. Participants who chose not to have surgery were treated with casting. All participants were stratified prior to analysis into highly and less-active groups based on pre-injury Rapid Assessment of Physical Activity Scores.

RESULTS

280 patients had 12-month assessments of outcomes. Highly active participants scored 8 and 5 points greater on the Michigan Hand Questionnaire at 6 weeks and 3 months respectively, p<0.05. Highly active participants demonstrated greater grip strength at the 3-month (p = 0.017) and 6-month (p = 0.007) time-points. Highly active participants treated with volar locking plate scored 10+ points greater on the Michigan Hand Questionnaire compared to the less-active group at the 6-week (p = 0.032), 3-month (p = 0.009) and 12-month (0.004) time points, with an effect size larger than 0.50, suggesting pre-injury level of activity had a significant clinical impact.

CONCLUSIONS

Higher levels of pre-injury activity are predictive of patient-reported and functional outcomes following distal radius fracture. Because of the greater PROs, the early mobility and lower risk of hardware infection reported in the literature, volar plating is preferable to other treatments for highly active patients who request and meet indications for surgery.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01589692.

Association between Pre-Intervention Physical Activity Level and Treatment Response to Exercise Therapy in Persons with Knee Osteoarthritis - An Exploratory Study

Objective

Examine whether pre‐intervention physical activity (PA) level is associated with achieving a positive treatment response of pain and/or function improvement after a 12‐week exercise intervention in participants with knee osteoarthritis (OA).

Methods

We performed a secondary analysis of a randomized, single‐blind comparative effectiveness trial showing similar treatment effects between Tai Chi mind‐body exercise and standard physical therapy intervention for knee OA. Baseline PA was assessed by a Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire and, in a subsample, by tri‐axial accelerometers. The Outcome Measures in Rheumatoid Arthritis Clinical Trials–Osteoarthritis Research Society International (OMERACT‐OARSI) dichotomous responder criteria was used for clinically meaningful improvement at follow‐up. Associations between baseline self‐reported PA by the CHAMPS questionnaire and outcomes of responders vs. nonresponders (reference group) were assessed using logistic regressions, adjusting for demographic covariates. We compared objectively measured PA by accelerometry between responders vs. nonresponders using Wilcoxon tests.

Results

Our sample consisted of 166 participants with knee OA who completed both baseline and 12‐week postintervention evaluations: mean age 60.7 year (SD 10.5), body mass index 32.4 kg/m² (6.9), 119 (72%) women, and 138 (83%) OMERACT‐OARSI responders. Neither time spent in total PA [odds ratio (OR) 1.00; 95% confidence interval (CI) 0.96, 1.03] nor time in moderate‐to‐vigorous PA (OR 1.01; 95% CI 0.93, 1.09) at pre‐intervention were associated with being a responder. Similar findings were observed in 42 accelerometry sub‐cohort participants.

Conclusion

Pre‐intervention PA levels (subjective report or objective measurement) were not associated with individuals achieving favorable treatment outcomes after a 12‐week exercise intervention, which suggests that regardless of pre‐intervention PA level, individuals will likely benefit from structured exercise interventions.