The relationship between vitamin D, vertebral deformity and quality of life in psoriatic arthritis

The aim of this study is to investigate the relation between vitamin D levels, vertebral deformities, functional status, quality of life, acute phase reactants and enthesopathy in patients with psoriatic arthritis (PsA).

Fifty-two patients with PsA and 52 controls were enrolled to the study. Routine blood tests and serums 25-(OH)D3 were measured. The thoracic and lumbar vertebrae deformities identified in the radiographies were evaluated by a radiologist. Psoriatic Arthritis Quality of Life (PSAQoL) was used for evaluating quality of life and disease activity parameters for PsA were assessed. In PsA patients, correlations was performed between the 25(OH)-D3 levels and PGE (patient global assessment), PHGE (Physician global assessment), tender JC (joint count), HAQ-S (Health Assessment Questionnaire for the Spondyloarthropathies), PSAQoL, MASES (Maastricht Ankylosing Spondylitis Enthesitis Score) and BASDAI(Bath Ankylosing Spondylitis Disease Activity Index) values.

The results showed that 25(OH)-D3 levels was not correlated with these values. (p>0.05 for r = -0.171, r = -0.167, r=-0.069, r=-0.236, r=-0.062, r= -0.058 and r = -0.106 respectively). It was determined that the PSAQoL score had a positive and statistically significant correlation with the DGD, swollen JC, CRP, HGD, tender JC, VAS-pain, HAQ-S, MASES and BASDAI values in PsA patients. (p>0.05 for r=0.291, r=0.324, r=0.346, r=0.312; and p=0.001 for r=0.472, r=0.380, r=0.565, r=0.696, r=0.359, r=0.633, respectively) Statistical analyses demonstrated that PsA patients with vertebral deformities had higher numbers of tender joints, more prolonged periods of morning stiffness, higher DAS28-ESR (Disease Activity Score) scores, and higher levels of vitamin D (p<0.05, p<0.05, p=0.05 and p<0.05, respectively). The multiple logistic regression analysis indicated that the only factor which had an effect on the development of vertebral deformities was the use of steroids.

This result has demonstrated that psoriatic arthritis has a considerable effect on patient quality of life. Most significant factors that affecting quality of life were physical pain and disability while vertebral deformities and 25-(OH)D3 had no significant effect.