L. Idolazzi1, G. Bagnato2, G. Bianchi3, M. Caminiti4, F.P. Cantatore5, A. Del Puente6, B. Frediani7, A. Iagnocco8, M. Muratore9, M.L. Sorgi8, S. Adami1, M. Rossini1, Vitamin D in Rheumatoid Arthritis (VITAR) Study Group. 1University, Verona; 2University, Messina; 3Ospedale La Colletta, Arenzano; 4Az. Ospedaliera ''Bianchi-Melacrino-Morelli'', Reggio Calabria; 5University, Foggia; 6University Federico II, Napoli; 7University, Siena; 8University La Sapienza, Roma; 9Ospedale, Lecce, Italy

Background: Vitamin D deficiency is quite common among elderly individuals and it is associated with musculoskeletal symptoms. In rheumatoid arthritis (RA), its deficiency may be associated with increased disease activity and disability.
Objectives: To estimate the prevalence and determinants of vitamin D deficiency and secondary hyperparathyroidism and to study the association of vitamin D deficiency with disease activity and disability in RA.
Methods: We studied 1191 consecutive RA patients (85% women) from 22 Italian rheumatology centres. Together with parameters of disease activity, calcium intake, mean summer sun exposure time (sun exposure) and bone mineral density, in all patients the serum levels 25-hydroxyvitamin D [25(OH)D] and serum parathyroid hormone were measured in a centralized laboratory.
Results: Fifty five% of the patients were not taking vitamin D supplements. The proportion of patients with 25(OH)D level <20 ng/ml was 52% in the subjects not on vitamin D supplements and in one third of those supplemented.
In non-supplemented patients 25(OH)D levels were significantly correlated with Health Assessment Questionnaire Disability Index, Mobility Activities of daily living score, and number of swollen joints. Significantly lower 25(OH)D values were found in patients not on disease remission or poorly responding to treatment, with the highest Steinbrocker functional state, and on treatment with disease-modifying antirheumatic drug or anti-TNFα agents. Good predictors of 25(OH)D values (p>0.000) were body mass index (BMI, kg/m2) and sun exposure.
The patients with the worse indices of disease activity were spending significantly less time at sunshine. The association between disease activity scores and 25(OH)D levels remained statistically significant also for 25(OH)D levels adjusted for both sun exposure and BMI.
Conclusion: In RA patients, disease activity scores are inversely related with 25(OH)D levels, and these relationships remained statistically significant even when the 25(OH)D values are adjusted for the known risk factors for vitamin D deficiency. The causality (low 25(OH)D levels being responsible of worse disease activity) of these associations must be confirmed by longitudinal studies by examining the clinical response to large vitamin D supplements.
Disclosure of Interest: None declared

Citation: Ann Rheum Dis 2010;69(Suppl3):516

Session: Rheumatoid arthritis – comorbidity and clinical aspects


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