Vitamin D status was often low in the winter in patients with ankylosing spondylitis, but levels were comparable to serum levels found in healthy control participants and were not correlated with disease activity, according to researchers from the University of Gothenburg.
In a study, the results of which were presented at the European League Against Rheumatism Annual European Congress of Rheumatology, serum vitamin D levels of 203 patients with ankylosing spondylitis (AS) and 120 healthy control participants residing in Gothenburg, Sweden, were measured in late winter. Disease activity was assessed using erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), AS disease activity (ASDAS-CRP), the Bath AS Disease Activity Index (BASDAI), the Bath AS Patient Global Score (BAS-G), the Bath AS Functional Index (BASFI) and the Bath AS Metrology Index (BASMI). Fecal calprotectin was measured from patients’ stool samples. Radiographs of the lateral spine were scored for vertebral fractures and osteoproliferation using the Genant score and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS), and dual-energy X-ray absorptiometry was used to measure bone mineral density in the femoral neck and lumbar spine.
Approximately 50% of patients with AS had serum vitamin D below 50 nmol/L, but the results were similar in healthy participants. No association was seen with vitamin D levels and fecal calprotectin, gastrointestinal symptoms, disease activity, vertebral fractures, mSASSS or bone mineral density, according to the researchers.
“We suggest that the lower vitamin D levels in AS, previously found by others, is caused by reduced outdoor UVB exposure,” the researchers concluded. “It is, however, imperative to diagnose and treat vitamin D insufficiency in AS given the increased risk of osteoporotic fractures associated with the disease.” – by Shirley Pulawski
Klingberg E, et al. Paper #SAT0279. Presented at: European League Against Rheumatism Annual European Congress of Rheumatology; June 10-13, 2015; Rome.
Disclosure: The researchers report no relevant financial disclosures.