Water exercises do not improve body composition in women with rheumatoid arthritis: The hydratrial (hydrotherapy in rheumatoid arthritis)

Aims/Objetivos: Our aim was to compare the peak quadriceps strength in RA women after 16 weeks of physical exercises performed in water or land. Besides, we assessed any changes in body composition, disease activity and disability. Methods/Métodos: A total of 128 patients, aged 40‐65 years old, with diagnosis RA (ACR, 1987) were enrolled to this 16‐ week randomized controlled trial (The HydRA trial). They were randomized for 2 groups of exercises (LE: land exercises, N030; WE: water group exercises, N030) or control group [CG], N029. The program was based on 12 exercises for legs that were performed in a sitting position, with a progressive increase of the loads. Cardiovascular fitness was measured by a standardized exercise test, at rest and under physical stress (Micromed ErgoPC13® Windows). Disease activity was assessed by DAS28 and disability by HAQ. Muscle strength of knee flexors and extensors were studied with the isokinetic dynamometer (Biodex System 3 Pro®) and the body composition by DXA (GE‐Lunar, DPX MD+), before and after the intervention. Statistical analysis included Bonferroni and chi‐squared test, ANOVA and regression models. P value below 0.05 was considered significant. Results/Resultados: 82 patients finished the HydRA trial in 16 weeks. Dropout rate was 13.5%. Both 3 groups were matched to age, weight, BMI and disease duration. After 8 and 16 weeks of intervention, there was significant improvement of disease activity and disability in WE, compared to LE and CG. There was no significant difference on muscle strength of flexors and extensors of both knees, neither fat mass, total and skeletal lean mass in either group over time. WE had better compliance than other 2 groups in 8 and 16 weeks. Concomitant medications did not change in 3 groups and no serious adverse event was noticed in 16 weeks of intervention. Conclusion/Conclusão/Conclusión: The water resistance did not provide significant changes of body composition, including lean, fat and bone mass in 16 weeks of physical training. Besides, it did not increase the quadriceps muscle strength, although it has caused a relevant improvement of disease activity and disability.