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.


Assesment of Physical Activity by Accelerometry: Relationship Between Physical Function and Disease Activity in Rheumatoid Arthritis Patients.

Hernandez-Hernandez1,  Vanesa, Delgado-Frias1,  Esmeralda, Ferraz-Amaro1,  Ivan, Garcia-Dopico2,  Jose A., Medina2,  Lilian, Alonso1,  Inmaculada, Arce-Franco1,  M. Teresa

Rheumatology Service, La Laguna, Spain
Central Laboratory, La Laguna, Spain
Hospital Universitario de Canarias, La Laguna, Spain

Background/Purpose:

In patients with rheumatoid arthritis (RA) the ability to perform activities of daily life may be deteriorated. However, the relationship between disease activity and global movement capability remains to be fully clarified in theese patients. The aim of this study was to determine to which extent RA features affect physical activity in these patients

Methods:

66 RA patients, without significant involvement of lower limbs, (56/10 female/male, age 53.6±9.6 years, disease duration 7.5±4.8 years) underwent physical activity monitoring through two methods: triaxial accelerometry output measured in vector magnitude (counts·min-1) and International Physical Activity Questionnaire (IPAQ) (MET-min/week). Patients were retested 6 months later to assess pre and post-test reliability. Demographic data, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Health Assessment Questionnaire Disability index (HAQ), Disease Activity Score (DAS 28), and quality of life through Functional Assessment of Chronic Illness Therapy (FACIT), and SF-36v2 Health Survey were performed at baseline and after 6 months of follow up.

Results:

Univariate analysis showed that patients with higher DAS28 score express lower physical activity (coefficient beta 24.5 counts·min-1, (-46.7)–(-1.57)IC95%, p=0.03). These data remain statistically significant when adjusted for age, disease duration and body mass index. Similarly results were obtained for physical function (HAQ), showing a non-significant trend (coefficient,-35.2 counts·min-1,(-90.6)-(20.1) IC95%, p=0.07). Regard IPAQ questionnaire, the physical activity was also associated with HAQ (r2=-0.41, p=0.00) and FACIT (r2=-0.31, p=0.03) but not with DAS28 score. In fact, IPAQ and accelerometry did not correlate in RA patients (intraclass correlation index 0.01, (-0.29)-(0.32)IC95%, p=0.47). SF-36, both physical and mental component, did not showed relationship with physical activity by neither IPAQ nor accelerometry. Six months later reliability study showed that HAQ (coefficient beta -45.4 counts·min-1, (-70.9)–(-19.9)IC95%, p=0.00) and DAS28 (coefficient beta -15.9 counts·min-1, (-34.3)-(-3.35) IC95%, p=0.04) were still correlated with physical activity measured by accelerometry. This data suggest an optimal test-retest reliability. Multivariate analysis to construct the best explaining model for physical activity, assessed by accelerometry, in RA patients showed that disease duration, HAQ, DAS28 and ESR explain 29% of physical activity variation (r2 adj=0.29).

Conclusion:

Physical activity is related overtime to both disease activity and physical function in RA patients. Objective assesment of physical activity by accelerometry may be a valuable aspect to take into account in the evaluation of RA patients in clinical practice.

To cite this abstract, please use the following information:
Hernandez-Hernandez, Vanesa, Delgado-Frias, Esmeralda, Ferraz-Amaro, Ivan, Garcia-Dopico, Jose A., Medina, Lilian, Alonso, Inmaculada, et al; Assesment of Physical Activity by Accelerometry: Relationship Between Physical Function and Disease Activity in Rheumatoid Arthritis Patients. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :2115
DOI:

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