Handgrip strength, physical activity, and body composition in young adults with juvenile idiopathic arthritis

Assessment of sarcopenia in young patients with inflammatory arthritis: a cross-sectional study

Sarcopenia is a disease characterized by decreasing muscle mass and strength or performance. The prevalence of sarcopenia in rheumatic diseases has been evaluated in single diseases using various diagnostic approaches, generating conflicting data. The study aims to investigate sarcopenia prevalence in young adults with inflammatory arthritis (IA) and to detect factors associated with low muscle mass and strength. The single-center, cross-sectional study included 138 young adults with IA. Dynamometry with a Jamar hand dynamometer was used to determine handgrip strength. Thresholds for reduced muscle strength were < 27 kg for males and < 16 kg for females. To determine skeletal mass index (SMI), dual photon X-ray absorptiometry (DXA) was done with such cut-off points < 5.67 kg/m2 in females and < 7.0 kg/m2 in males. Patients with both reduced muscle mass and strength were considered as sarcopenic. Logistic regression analyses estimated between sarcopenia and associated factors. Statistical significance was defined as a p-value < 0.05. The prevalence of sarcopenia was about 47% in all IA and was significantly different between juvenile idiopathic arthritis (JIA), spondyloarthritis (SpA), and rheumatoid arthritis (RA) groups (p = 0.006). At multivariable analysis, body mass index (BMI) (OR 0.84; CI 95% 0.72-0.86, p = 0.02), bone mineral density (BMD) at femur neck (OR 0.01; CI 95% 0.001-0.268, p = 0.01), 25-hydroxyvitamin D (25(OH)D) (OR 0.96; CI 95% 0.93-0.98, p = 0.001), and disability by Health Assessment Questionnaire (HAQ) (OR 14.54; CI 95% 4.92-51.77, p < 0.001) were associated with a significantly increased risk of sarcopenia. The results of our study demonstrate a high prevalence of sarcopenia among young patients with IA. In these participants, lower BMI, lower BMD, 25(OH)D concentration, and higher HAQ were linked to sarcopenia.

Factors associated with sarcopenia among young adults with juvenile idiopathic arthritis: a cross-sectional study

BACKGROUND

Sarcopenia is a generalized loss of skeletal muscle mass, strength, and performance, and early identification is crucial to minimize adverse outcomes. While sarcopenia is well-studied in older populations, data on its prevalence and risk factors in young adults with juvenile idiopathic arthritis (JIA) remain limited.

OBJECTIVES

The study aimed to evaluate the prevalence of sarcopenia in young adults with JIA and to identify associated risk factors.

METHODS

A cross-sectional single-center study was conducted at the Rheumatology Department of Communal Noncommercial Institution "Oleksandrivska Clinical Hospital", Kyiv, Ukraine, involving 70 patients between November 2020 and November 2022. Initially, 84 patients were recruited; however, 14 were excluded due to joint replacement, diabetes, or refusal to participate. Sarcopenia was diagnosed using the Find-Assess-Confirm-Severity algorithm, assessing muscle strength with a dynamometer, confirming sarcopenia using dual-energy X-ray absorptiometry, and determining severity via gait speed tests. Univariable and multivariable logistic regression was used to identify factors associated with sarcopenia and reported as odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Low handgrip strength, sarcopenia, and severe sarcopenia were observed in 64% (45/70), 59% (41/70), and 34% (24/70) of the patients, respectively. Men were less likely to lose muscle mass than women were (OR 0.29, 95% CI 0.10-0.89; p = 0.03). Sarcopenia was significantly predicted by disease activity according to the Disease Activity Score 28 based on erythrocytes sedimentation rate (DAS28-ESR) and clinical Juvenile Arthritis Disease Activity Score (cJADAS27) (OR 2.08, 95% CI 1.15-3.76; p = 0.01; OR 1.15, 95% CI 1.04-1.27; p = 0.007, respectively), articular and extra-articular Juvenile Arthritis Damage Index (JADI) (JADI-A OR 2.29, 95% CI 1.23-4.25; p = 0.009; JADI-E OR 3.15, 95% CI 1.36-7.29; p = 0.008, respectively), and functional capacity according to the Health Assessment Questionnaire (OR 4.14, 95% CI 1.38-12.5; p = 0.01).

CONCLUSION

Sarcopenia in young adults with JIA was associated with disease activity (measured by DAS28-ESR and cJADAS27), articular and extra-articular damage (measured by JADI indices), and lower functional capacity.