Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Associations Between Changes in Physical Function and Physical Activity in Response to An Exercise Program in Patients with Rheumatoid Arthritis.

Almeida,  Gustavo JM, Piva,  Sara R.

Background/Purpose:

Measures of physical function (PF) characterize patient's ability to perform functional activities whereas measures of physical activity (PA) informs about the amount of activities patients perform. Cross-sectional studies in patients with Rheumatoid Arthritis (RA) have reported conflicting evidence about the associations between these two domains of PF and PA. Longitudinal studies investigating how well changes in PF associate with changes in PA are lacking. If changes in these two domains are associated targeting exercise to improve PF can result in increases in PA participation in patients with RA. The aim of this study was to explore the associations between changes in PF and changes in PA in patients with RA.

Methods:

This is an interim analysis from a randomized controlled trial on the effect of a 12-week strengthening exercise for the lower extremities on muscle function in patients with RA. At this point, data from 12 subjects (9 females, age 65.1±9.5, BMI 30.4±8, disease duration 20.4±11.1 years, and Health Assessment Questionnaire-HAQ.82±.75) were analyzed. PF was measured by the Lower Extremity Functional Scale (LEFS), quadriceps strength measured in an isokinetic dynamometer, timed 5-chair rise, and time to go up and down a flight of stairs. PA was measured by the Physical Activity Scale for Individuals with Physical Disabilities questionnaire (PASIPD) and by the SenseWear armband, a multi-sensor portable activity monitor that provided data on energy expenditure (EE) of PA performed above 1 metabolic equivalent level (PAEE>=1MET), EE of PA performed above 2 METs (PAEE>=2METs), EE of PA performed above 3 METs (PAEE>=3METs). Spearman or Pearson correlation coefficients were calculated between changes in PF and changes in PA according to data distribution.

Results:

The associations between changes in PF and changes in PA are shown in the Table. Results indicated that the associations between changes in PF and changes in PA were higher for the more demanding functional tasks such as chair rise and climbing stairs, and lower for changes in quadriceps strength and PA. Changes in self-reported PF and real-time PA did not associate, whereas the association between changes in self-reported PF and self-reported PA was moderate, which may have occurred due to both measures being self-reported.

Table. Associations between changes (D) in physical function (PF) and physical activity (PA) variables. Associations represent Pearson Correlations, unless otherwise indicated.

Variables exploredCorrelation coefficients between PF and PA variables
 D Quad StrengthD Chair timeD Stair timeD LEFS
D PAEE>=1MET0.37-0.70*-0.51*0.09
D PAEE>=2MET0.27-0.68*-0.55*0.10
D PAEE>=3MET0.21-0.43-0.410.01
D PASIPD score0.64*-0.32-0.88**0.41
Quad Strength = quadriceps strength; Chair time = timed 5-chair rise; Stair time = time to go up and down a flight of stairs;† Spearman Rho Correlation Coefficients;*p<=.05;**p<=.01.

Conclusion:

The clinical relevance of this study is that improvements in PF to perform demanding functional tasks seem to play a role in increasing PA in patients with RA. Perhaps targeting exercises to improve patient's ability to perform more demanding functional tasks may increase the participation in PA. Increasing participation in regular PA is important for patients with RA because it can prevent several co-morbidities associated with the disease, and maintain mobility that is also reduced in these patients.

To cite this abstract, please use the following information:
Almeida, Gustavo JM, Piva, Sara R.; Associations Between Changes in Physical Function and Physical Activity in Response to An Exercise Program in Patients with Rheumatoid Arthritis. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :1561
DOI:

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