आईएसएसएन: 2161-1149 (Printed)
Chen J, Chen X, Liu D, Sigdel KR, Ruan G,Tong S, Prince RL
Objectives: The role of bone disease in spondyloarthropathy (SpA) remains of great interest with evidence of an increased risk of bone fragility and fracture. The effects of lifestyle factors such as sun light exposure and vitamin D deficiency on SpA remain uncertain. The study was to examine those factors on skeletal integrity in axial spondyloarthropathy (axSpA) patients associated with sub-clinical osteomalacia.
Material and Methods: 95 axSpA patients and 74 healthy controls in the same season were enrolled. ASAS-endorsed disease activity score (ASDAS), 25-hydroxyvitamin D, parathyroid hormone (PTH), bone turnover biomarkers procollagen type 1 N-terminal peptide (PINP) and osteocalcin(OC), serum C-telopeptides of type I collagen (sCTX), serum alkaline phosphatase (sALP), adjusted calcium, C-reactive protein, bone minimal density (BMD) of total proximal femur and lumbar spine were measured. Questionnaires on daily sun exposure time and other factors were ascertained.
Results: axSpA patients were with significantly decreased vitamin D and raised sALP levels than controls (p<0.001). 74% of axSpA patients had vitamin D deficiency. Their vitamin D levels were inversely related to the disease duration (r=-0.234, p<0.05) but positively to daily sunlight exposure time and calcium (r=0.064, p<0.001, respectively). axSpA patients had significantly higher bone turnover biomarkers sCTX and OC (p<0.05), and significantly lower femoral neck T and Z scores in BMD than controls (p=0.000).
Conclusion: Vitamin D insufficiency exist in most (74%) of axSpA patients. axSpA patients exhibited significantly lower vitamin D and raised ALP levels, and with significantly higher bone turnover biomarkers and low BMD than controls, which indicated that subclinical biochemical osteomalacia associated with most axSpA patients.