Tight control of disease activity fails to improve body composition or physical function in rheumatoid arthritis patients

OBJECTIVE

RA typically features rheumatoid cachexia [loss of muscle mass (MM) and excessive total fat mass (TFM), especially trunk FM], which contributes to physical disability. Since rheumatoid cachexia is driven by inflammation, it would be anticipated that the success of tight control of disease activity, such as treat-to-target (T2T), in attenuating inflammation would benefit body composition and physical function. This aim of this cross-sectional study was to assess the impact of T2T on body composition and objectively assessed function in RA patients.

METHODS

A total of 82 RA patients exclusively treated by T2T, were compared with 85 matched sedentary healthy controls (HCs). Body composition was estimated by DXA, with appendicular lean mass the surrogate measure of total MM. Physical function was assessed by knee extensor strength, handgrip strength, 30 s sit-to-stands, 8' up and go, and 50' walk (tests which reflect the ability to perform activities of daily living).

RESULTS

Although generally well treated (mean DAS28 = 2.8, with 49% in remission), RA patients had ∼10% proportionally less appendicular lean mass and were considerably fatter (by ∼27%), particularly in the trunk (∼32%), than HCs. All measures of function were 24-34% poorer in the RA patients relative to HC.

CONCLUSIONS

Despite marked improvements in disease control (most patients achieving or approaching remission), the relative loss of MM and increased adiposity in RA patients compared with matched HCs was similar to that observed pre-T2T. Additionally, performance of objective function tests was unchanged from that reported by our group for pre-T2T RA patients. Thus T2T, even in responsive RA patients, did not attenuate rheumatoid cachexia or improve objectively assessed function.

Patellar tendon properties and lower limb function in rheumatoid arthritis and ankylosing spondylitis versus healthy controls: a cross-sectional study

Objective. Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) lead to inflammation in tendons and peritendinous tissues, but effects on biomechanical tendon function are unknown. This study investigated patellar tendon (PT) properties in stable, established RA and AS patients. Methods. We compared 18 RA patients (13 women, 59.0 ± 2.8 years, mean ± SEM) with 18 age- and sex-matched healthy controls (58.2 ± 3.2 years), and 12 AS patients (4 women, 52.9 ± 3.4 years) with 12 matched controls (54.5 ± 4.7 years). Assessments with electromyography, isokinetic dynamometry, and ultrasound included quadriceps muscle force and cross-sectional area (CSA), PT stiffness, and PT CSA. Additionally, measures of physical function and disease activity were performed. Results. PT stiffness and physical function were lower in RA and AS patients compared to healthy controls, without a significant difference in force production. PT CSA was significantly larger leading to reduction in Young's modulus (YM) in AS, but not in RA. Conclusion. The adverse changes in PT properties in RA and AS may contribute to their impaired physical function. AS, but not RA, leads to PT thickening without increasing PT stiffness, suggesting that PT thickening in AS is a disorganised repair process. Longitudinal studies need to investigate the time course of these changes and their response to exercise training.

Effects of different local cryotherapies on systemic levels of TNF-α, IL-6, and clinical parameters in active rheumatoid arthritis

Cryotherapies are frequently used to supplement the rehabilitation of patients with rheumatoid arthritis (RA) owing to their analgesic and anti-inflammatory effects. Forty patients with active RA were recruited and received 10 days of comprehensive therapy with different local cryotherapies. None of the respondents were subjected to biological treatment. They were divided into two groups according to the therapy received: nitrogen vapour at -160 °C (group I) or cold airflow at -30 °C (group II). Levels of tumour necrosis factor α (TNF-α), interleukin 6 (IL-6), disease activity score (DAS28), and functional variables were used to assess the outcomes. After the therapy, both groups exhibited similar improvements. Significant reduction in TNF-α level (nitrogen: p < 0.01; cold air: p < 0.05) and no change in IL-6 were observed. DAS28, the clinical severity of pain, duration of morning stiffness, degree of self-reported fatigue, and health assessment questionnaire (HAQ) scores improved significantly. In addition, the active range of knee extension, time, and the number of steps in the 50-m walk test also clearly got better in both groups. The 10-day comprehensive therapies including different local cryotherapies for the patients with RA cause significant decrease in TNF-α systemic levels, meaningly improve DAS28, HAQ scores, and some functional parameters, but do not change IL-6 levels. However, there were no differences in the effectiveness of either cryotherapy.