Bone Abstracts

Introduction: The loss of muscle mass (MM) is a serious problem which has been demonstrated in patients with rheumatoid arthritis. There are few studies about the loss of MM in patients with spondyloarthritis (Spa). In a recent case–control study in our department, the risk of sarcopenia in Spa patients was twice than in a healthy control group.

Objective: To assess muscle mass index (MMI) in patients with axial Spa and to search a relation between sarcopenia and radiological damage.

Methods: Observational study, in which modified stoke ankylosing spondylitis spinal score (mSASSS) was assessed in a cohort of patients with axial Spa and muscle mass index (MMI) was determined, from the value of MM, using Lee’s equation. Data were treated using SPSS version 17.0. Values of P<0.05 were considered significant.

Results: Forty patients were enrolled in this cohort: 19 were males and 21 were females; mean age was 41.1±14.4 years and mean disease duration was 8.8±10.1 years. Mean mSASSS was 8.5±12.1; mean IMM was 7.88±1.02 kg/m² in males and 7.63±0.99 kg/m² in females; 17 patients had normal IMM, 7 had grade I sarcopenia and 16 had grade II sarcopenia. No difference with statistical significance was found between the mSASSS value in different sarcopenia grades (P=0.091). There was a moderate negative correlation between IMM and mSASSS in males (P=−0.384), but only weak negative correlation in females (P=−0.016).

Conclusion: In our cohort, a correlation between the presence of sarcopenia and a radiological aggressive disease was found in Spa males. However, patients with different grades of sarcopenia didn’t present significantly different mSASSS values.

This study has some limitations including the sample size, potential confounding factor such the bias of measurement and the use of a non-validated equation to Portuguese population to calculate MM. However, this work serves as a stimulus for future studies.