Factors affecting walking ability in female patients with rheumatoid arthritis

PLoS One. 2018 Mar 27;13(3):e0195059. doi: 10.1371/journal.pone.0195059. eCollection 2018.

Abstract

Objective: To determine the factors associated with gait parameters in female patients with rheumatoid arthritis (RA).

Methods: The gait analysis was performed in a large cohort of RA patients, and three basic gait parameters (step length, cadence and gait speed) were calculated. Clinical and laboratory data were also collected. Factors associated with gait parameters were analyzed using multivariable linear regression in the three models with forced entry. Then, we divided those patients with Health Assessment Questionnaire disability index (HAQ) scores ≤ 0.5 into two groups according to their gait speed that were compared to identify the characteristics of patients with a good HAQ score but poor walking ability.

Results: A total of 318 female patients were analyzed. Knee extension strength had the strongest positive association with all three gait parameters (P < 0.0001), while methotrexate use was also positively associated with all three gait parameters (step length: P < 0.05, cadence: P < 0.05 in model 1 and 2; P < 0.01 in model 3, gait speed: P < 0.01). The disease activity score was negatively associated with step length and gait speed (step length, gait speed: P < 0.01 in model 1 and 2; P < 0.05 in model 3). 26% of patients with good HAQ scores showed slow gait speed. Patients with good HAQ scores and slow gait speed had higher disease activity scores (P < 0.05) and lower knee extension strength (P < 0.0001) than those with good HAQ scores and normal gait speed.

Conclusions: High knee extension strength, low disease activity and administration of methotrexate were strongly associated with good walking ability in female patients with RA. And, even if patients showed good HAQ scores, about quarter of those patients had poor walking ability, and they showed higher disease activity, lower knee extension strength, compared to the patients with normal gait speed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arthritis, Rheumatoid / drug therapy
  • Arthritis, Rheumatoid / metabolism
  • Arthritis, Rheumatoid / pathology*
  • C-Reactive Protein / analysis
  • Female
  • Gait* / drug effects
  • Humans
  • Knee / physiopathology
  • Linear Models
  • Methotrexate / pharmacology
  • Methotrexate / therapeutic use
  • Middle Aged
  • Risk Factors
  • Severity of Illness Index
  • Walking Speed / drug effects

Substances

  • C-Reactive Protein
  • Methotrexate

Grants and funding

M.H. and M.T. belong to a department that is financially supported by 4 pharmaceutical companies (Mitsubishi-Tanabe, Chugai, Ayumi, and UCB Japan) and a city government (Nagahama city). H.I. has received a research grant and/or speaker fee from Bristol-Myers, Astellas, and Eli Lily. Y.M., M.T., A.H., M.F., M.A., H.A., T.M., and S.M. declared no conflicts of interest. The sponsors were not involved in the study design; in the collection, analysis, interpretation of data; in the writing of this manuscript; or in the decision to submit the article for publication, and this commercial affiliation does not alter our adherence to PLOS ONE policies on sharing data and materials. The authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article. The funder provided support in the form of salaries for authors (H.I., M.H. and M.T.), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.