Evolução da força muscular respiratória, do status funcional e da capacidade funcional de mulheres com artrite reumatoide: estudo longitudinal de um ano

Abstract

Background: Rheumatoid Arthritis (RA) is an inflammatory, autoimmune, systemic, chronic, and progressive disease. It is more prevalent in women, in whom they have a younger age of onset, a lower percentage of autoantibody positivity, more pain and worse functional capacity, suggesting greater disease activity. Despite being associated with ventilatory dysfunctions, little is known about how respiratory muscle strength (RMS) evolves in women, especially its temporal evolution. Objective: To monitor the temporal evolution (12 months) of RMS, functional status and functional capacity in a group of adult women with RA. Methods: One-year longitudinal study approved by the UFAM Research Ethics Committee (CAAE 70481517.5.0000.5020). The RMS, the Modified Health Assessment Questionnaire (mHAQ), the Functional Status (ST) proposed by the ACR, the handgrip strength (HGS) and the six-minute walk test (6MWT) were evaluated. Descriptive statistics with absolute (N) and relative (%) frequencies were used to characterize the sample. Numerical continuous variables were presented as mean and standard deviation (SD) or median and interquartile range; categorical variables were presented in absolute and relative numbers. To analyze the evolution over time, the Generalized Estimating Equation model was used. Analyzes with p<0.05 were considered statistically significant. Results: The initial sample, collected in 2018, consisted of 44 adult women (mean age 48 ± 8 years), sedentary and overweight, with reduced RMS and HGS. In 2019, the sample was reassessed, with a loss of follow-up of approximately 7.30%, that is, with a sample of 41 women with RA. There was a statistically significant difference in relation to MIP (the mean in 2018 was -63,6±3,4 cmH2O and in 2019, -56,9±3,4 cmH2O, with p=0,045) and in relation to MEP (the mean in 2018 was +72,3±3,1 cmH2O and in 2019 it was +62,6±3,0 cmH2O, with p=0,006). There was also a difference in functional status, with a higher frequency of women considered normal in the mHAQ classification in 2019 compared to 2018 (p<0,001). The 6MWT and HGS showed no differences between the measures evaluated in 2018 and 2019. The RMS worsened in one year, but functional status and functional capacity were maintained or even improved. Conclusion: This study demonstrated that adult women with RA may have reduced respiratory muscle strength that worsens over time, even if functional status and functional capacity do not deteriorate.