Background: Vitamin D is crucial in calcium homeostasis, playing a role in the modulation of the immune system. The objectives were to assess BMD, bone turnover markers and 25OHD levels in psoriatic arthritis (PsA) patients; and to investigate the relationship between 25OHD and disease activity.
Methods: Fifty patients were recruited. Patients with axial involvement were excluded. Calcium, phosphorus, 25OHD, PTH, P1NP and βCTX were measured as bone turnover markers. BMD was measured at the lumbar spine and hip by DXA. Disease activity was assessed using DAS-28, BASDAI, CPR and ESR levels; HAQ for functional impairment.
Results: Twelve premenopausal women, 22 postmenopausal women and 16 men were included. The clinical forms of PsA were: 32% oligoarticular and 54% poliarticular. Mean disease duration was 111±108 months, 25OHD levels was 28,91±13,3 ng/dl, DAS 28 1,61±0,70 and BASDAI 3,24±1.99. Sixteen patients (32%) presented insufficient 25OHD levels (< 30 ng/ml) and 22% showed deficiency(< 20 ng/ml). Frequency of osteoporosis was 14% and osteopenia 49%, being higher in postmenopausal women (75%) rather than premenopausal (25%) or men (29.4%). P1NP 38,9 (14-72) ng/ml and βCTX 341,2 (142-866) pg/ml had normal values. Six fractures were registered. Mean values of ESR, CPR and HAQ were 10,9±11,41 mm/h, 5,38±0,86 mg/L and 0,33±0,48 respectively, in patients with normal vitamin D levels; whereas patients with low vitamin D levels presented higher values (ESR, CPR and HAQ mean values of 12,1±9,82 mm/h, 6,48±5,38 mg/L and 0,37±0,56). Our results are not statistically significant due to low sample population.
Conclusions: High prevalence of 25OHD insufficiency was found. 63% had decreased bone mass. An inverse correlation between 25OHD levels, disease activity and functionality is shown. There is a relationship between high disease activity in PsA and 25OHD metabolism and increased bone resorption.
Disclosure: The authors declared no competing interests.