Abstract
Sarcopenia is an age-related disease with an increased risk of mortality. It is emerging that low serum vitamin D (25(OH)D) affects the sarcopenic state in general, but in rheumatoid arthritis (RA), these associations are not understood although the prevalence of vitamin D insufficiency is high in RA. We conducted a cross-sectional study of older female outpatients from our cohort (KURAMA) database. We measured skeletal muscle mass, handgrip strength, and gait-speed to diagnose severe sarcopenia. The serum 25(OH)D concentration was measured using electrochemiluminescence immunoassay. A total of 156 Patients (sarcopenia:44.9%, severe sarcopenia: 29.5%, and without sarcopenia: 25.6%) were enrolled. Classification of vitamin D status at a cutoff point of median 25(OH)D concentration revealed that low 25(OH)D status was associated with a high prevalence of severe sarcopenia and with low measured values of muscle mass, handgrip, and gait-speed. Furthermore, multiple regression analysis identified that low 25(OH)D status was associated with a high prevalence of severe sarcopenia (OR 6.00; 95% CI 1.99–18.08). In components of sarcopenia, both low physical performance and muscle mass were associated with low 25(OH) status. In conclusion, vitamin D levels are associated with severe sarcopenia and its components, and modification of vitamin D status including vitamin D supplementation may play a role in improving sarcopenia in RA.