Ankylosing spondylitis confers substantially increased risk of clinical spine fractures: a nationwide case-control study.

UNLABELLED: Ankylosing spondylitis (AS) leads to osteopenia/osteoporosis and spine rigidity. We conducted a case-control study and found that AS-affected patients have a 5-fold and 50% increased risk of clinical spine and all clinical fractures, respectively. Excess risk of both is highest in the first years and warrants an early bone health assessment after diagnosis. INTRODUCTION: Ankylosing spondylitis (AS) is related to spine rigidity and reduced bone mass, but data on its impact on fracture risk are scarce. We aimed to study the association between AS and clinical fractures using a case-control design. METHODS: From the Danish Health Registries, we identified all subjects who sustained a fracture in the year 2000 (cases) and matched up to three controls by year of birth, gender and region. Clinically diagnosed AS was identified using International Classification of Diseases, 8th revision (ICD-8; 71249), and International Classification of Diseases, 10th revision (ICD-10; M45) codes. We also studied the impact of AS duration. Conditional logistic regression was used to estimate crude and adjusted odds ratios (ORs) for non-traumatic fractures (any site, clinical spine and non-vertebral) according to AS status and time since AS diagnosis. Multivariate models were adjusted for fracture history, socio-economic status, previous medical consultations, alcoholism and use of oral glucocorticoids. RESULTS: We identified 139/124,655 (0.11%) AS fracture cases, compared to 271/373,962 (0.07%) AS controls. Unadjusted (age- and gender-matched) odds ratio (OR) were 1.54 [95% confidence interval (95%CI) 1.26-1.89] for any fracture, 5.42 [2.50-11.70] for spine and 1.39 [1.12-1.73] for non-vertebral fracture. The risk peaked in the first 2.5 years following AS diagnosis: OR 2.69 [1.84-3.92] for any fracture. CONCLUSIONS: Patients with AS have a 5-fold higher risk of clinical spine fracture and a 35% increased risk of non-vertebral fracture. This excess risk peaks early, in the first 2.5 years of AS disease. Patients should be assessed for fracture risk early after AS diagnosis.

Prevalence and predictors of vitamin D deficiency in non-supplemented women with systemic lupus erythematosus in the Mediterranean region: a cohort study.

OBJECTIVES: Over the past few years researchers have suggested that vitamin D plays a diverse role in autoimmune diseases such as systemic lupus erythematosus (SLE). We sought to determine the prevalence and predictors of vitamin D deficiency in a cohort of non-supplemented female SLE patients from the Mediterranean region. METHODS: We carried out a prospective cohort study on all SLE patients who had visited the Department of Rheumatology at the Parc de Salut MAR (Barcelona, Spain) between June 2007 and December 2008, excluding those who had been taking vitamin D supplements (total: 73 patients, all female). For each patient, demographic information was collected; scores were measured for disease severity [SLE Disease Activity Index (SLEDAI)] and structural damage [Systemic Lupus International Collaborating Clinic/American College of Rheumatology, (SLICC/ACR) Damage Index]; pharmacological treatment was recorded; analytical variables were analysed; and plasma levels of 25-hydroxy vitamin D [25(OH)D] were quantified. RESULTS: Among the patients in our cohort, 68.5% [95% confidence interval (CI) 60.3-79.2] exhibited vitamin D deficiency [plasma level of 25(OH)D < 30 ng/mL]. The predictors for vitamin D deficiency were daily sunscreen use [odds ratio (OR) 1.67, p = 0.02] and high body mass index (BMI) (OR 1.32 when adjusted for seasons and patient age, p = 0.04). We did not find any correlation between vitamin D deficiency and SLEDAI score (p = 0.31), SLICC/ACR score (p = 0.82), or any other of the variables. CONCLUSIONS: Vitamin D insufficiency is highly prevalent among SLE patients, even in southern regions. Sunscreen use and obesity increase the risk. Clinicians should be aware of these factors and supplement SLE patients at risk of vitamin D deficiency accordingly.