Relationship Between Disease Activity and Serum Levels of Vitamin D Metabolites and Parathyroid Hormone in Ankylosing Spondylitis

Abstract

Vertebral fractures due to osteoporosis are a common but frequently unrecognized complication of ankylosing spondylitis (AS) and various factors may contribute to the development of osteoporosis in AS. It is known that inflammatory activity in rheumatic disease (i.e., proinflammatory cytokines) itself plays a possible role in the pathophysiology of bone loss. 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) seems to be another possible candidate for mediatory function in regulating both the inflammatory process and bone turnover. The aim of this study was to evaluate the relation between disease activity, bone turnover and calciotropic hormones. In 70 patients with established AS and an age- and sex-matched control group, the relation between disease activity (erythrocyte sedimentation rate, C-reactive protein, Bath Ankylosing Spondylitis Disease Activity Index), and serum levels of vitamin D metabolites, parathyroid hormone (PTH), bone alkaline phosphatase (bAP) and urinary pyridinium cross-links were determined. Serum levels of 1,25(OH)2D3 (p<0.01) and PTH (p<0.01) were negatively correlated with disease activity, the excretion of urinary pyridinium crosslinks showed a positive correlation with disease activity (p<0.01), and 1,25(OH)2D3 and PTH were positively correlated with bAP (p<0.01). These results indicate that high disease activity in AS is associated with an alteration in vitamin D metabolism and increased bone resorption. Furthermore, the decreased levels of 1,25(OH)2D3 may contribute to a negative calcium balance and inhibition of bone formation. Our results suggest further research is necessary to determine whether low levels of 1,25(OH)2D3 as an endogenous immune modulator suppressing activated T cells and cell proliferation may accelerate the inflammation process in AS.

Relationship of bone mineral density with disease activity and functional ability in patients with ankylosing spondylitis: a cross-sectional study

“…Apart from a cross-sectional design the limitation of this study is the lack of data for bone turnover markers, parathyroide hormone or vitamin D3, which could have revealed a better insight of association between activity parameters of both osteoporosis and AS [37,38].…”

Correlation of Vitamin D Deficiency and Sub-Clinical Osteomalacia in Axial Spondyloarthropathy.

“…Consistently, the acute phase reactant ESR and CRP was significantly elevated and inversely correlated with vitamin D levels in AS patients [13], disease activity ASDAS was negatively correlated with BMD because of vitamin D receptor gene may contribute to BMD differences in patients with AS, as gene polymorphisms are also linked to inflammatory activity [18]. Thus, osteoporotic risk may be significantly increased with raised serum levels of bone turnover markers and low levels of vitamin D. Previous study also has shown that the relationship between vitamin D with CRP and ESR, were significantly negatively correlated [19]. In addition, axSpA patients femoral BMD T/Z-score was negatively correlated with ALP, spinal stiffness and BMI.…”

Nutritional aspects and vitamin D supplementation in ankylosing spondylitis

“…While several studies had shown the aggravating effect of vitamin D's deficiency in the activity markers of AS disease [61][62][63][64] , other studies have not found any correlation [65][66][67] . Although, there is evidence for increased risk of AS in people with deficiency of vitamin D [68][69][70] further studies are required to clarify the causal relationship between the deficiency of vitamin D and activity of AS disease.…”

“…Additionally, Hmamouchi et al in another study, with 653 axSpA patients, mentioned that 25(OH)D had a significant inverse correlation with AS disease activity score, using CRP and Bath Ankylosing Spondylitis Metrology Index (BASMI) 73 . In studies that examined the relationship of 1,25(OH) 2 D with disease activity markers, found a significant inverse correlation between 1,25(OH) 2 D and ESR, BASDAI and CRP 63,64 . In contrast, there are studies that indicated that there is no correlation between 25(OH)D and disease activity [74][75][76] .…”

“…Osteoporosis usually occurs after 10 years of AS disease 80 . Individuals with AS having a deficiency of vit D, have higher prevalence of osteoporosis instead of patients with normal status of 25(OH)D. Several studies have indicated the relative low status of 25(OH)D with the appearance of osteoporosis, and that vitamin D deficiency leads to osteoporosis through the promotion of inflammatory activity 62,64,81 . As mention patients with AS, frequently present increased rate of osteoporosis, poor quality of bones and vertebral fractures.…”