High prevalence of low bone mineral density in patients within 10 years of onset of ankylosing spondylitis: a systematic review.

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease. Decreased bone mineral density (BMD) is a common complication of AS, with a prevalence range of 19 to 62 %. Many studies have shown decreased BMD in AS with long disease duration, but only a few studies investigated BMD in early AS. The prevalence of decreased BMD in early disease stages of AS has not yet been clearly described, and for that reason, we reviewed the literature which describes the prevalence of decreased BMD in AS patients with a short disease duration (<10 years). In this review, we included articles which used the modified New York criteria for the diagnosis of AS, included patients with a disease duration of less than 10 years, and used the WHO criteria for osteopenia and osteoporosis. Decreased BMD was defined as a T score < -1.0, including both osteopenia and osteoporosis. For this review, only articles that acquired BMD data of lumbar spine and femoral neck by DXA were used. The literature search provided us 35 articles of which 7 matched all our criteria, and they will be further outlined in this review. The overall prevalence of decreased BMD of the articles reviewed is 54 % (n = 229/424) for lumbar spine and 51 % (n = 224/443) for femoral neck. The prevalence of osteopenia vs. osteoporosis for lumbar spine is 39 vs. 16 % and for femoral neck, 38 vs. 13 %. This review showed a high total prevalence of 51-54 % decreased BMD and 13-16 % osteoporosis in AS with a short disease duration. This high prevalence was not to be expected in a relatively young and predominantly male population. Further research is needed to determine the clinical relevance of this low BMD by investigating the relation between low BMD and vertebral and nonvertebral fractures at this early stage in AS.

High frequency of vertebral fractures in early spondylarthropathies.

UNLABELLED: We demonstrated that vertebral fractures (VF) are commonly found in early SpA. Patients with VF had lower lumbar BMD than patients without VF. VF remained frequently 'unrecognized' and untreated. VF have been associated with more back pain, reduced Qol, and increased risk of future fractures which stresses the importance of recognition also in early stage SpA. INTRODUCTION: VF are a common complication of long-standing ankylosing spondylitis (AS). However, data of VF in early AS patients and in other spondylarthropathies (SpA) are scarce. Therefore we examined the prevalence of VF in early SpA patients and investigated the associations between VF and demographic and disease-related variables. METHODS: SpA patients were included consecutively and radiographs of the spine were made. VF were assessed according to the method of Genant et al.: fractures were defined as reduction of ≥20% of the vertebrae. Descriptive statistics, t-tests and logistic regression analyses were used to study the relationship between VF and demographic and disease-related variables, radiographic damage and BMD. RESULTS: A total of 113 early SpA patients were included with a disease duration of 7 months, a mean age of 37 years. Seventeen patients (15%) had at least one VF. Fourteen patients had one VF, three patients had two VF. Most VF were located at Th6-Th8. In patients with VF, bone mineral density (BMD) of lumbar spine was lower than BMD of patients without VF (t-test: p = 0.043). Axial Psoriatic Arthritis (PsA) was significantly associated with a higher risk for VF (odds ratio [OR]: 4.62, 95% confidence interval [CI] 1.15-18.58, p = 0.031). No significant associations were found with disease activity variables nor with radiographic severity. CONCLUSION: In a group of 113 early, young SpA patients, 15% already had at least one VF. Most VF were asymptomatic, undetected by routine diagnostic procedures and located at the mid-thoracic spine. The VF were associated with low BMD of the lumbar spine and with axial PsA.

Low bone mineral density is related to male gender and decreased functional capacity in early spondylarthropathies.

The objective of this study was to determine the prevalence and risk factors of low bone mineral density (BMD) in patients with spondylarthropathies (SpA) at an early stage of disease. In this cross-sectional study, the BMD of lumbar spine and hips was measured in 130 consecutive early SpA patients. The outcome measure BMD was defined as (1) osteoporosis, (2) osteopenia, and (3) normal bone density. Logistic regression analyses were used to investigate relations between the following variables: age, gender, disease duration, diagnosis, HLA-B27, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), extra-spinal manifestations and medication, with outcome measure low BMD (osteopenia and/or osteoporosis). The SpA population had a median time since diagnosis of 6.6 months and a disease duration of 6.3 years. In total, 9% of the early SpA patients had osteoporosis, 38% osteopenia, and 53% normal BMD. On univariate analyses, male gender, diagnosis of ankylosing spondylitis, increased CRP, high BASFI, and high BASMI were significantly associated with low BMD. Factors showing a relation with low BMD in the multivariate model were male gender (OR 4.18, 95% confidence interval (CI) 1.73-10.09), high BASMI (OR 1.54, 95% CI 1.14-2.07), and high BASFI (OR 1.18, 95% CI 1.00-1.39). In early SpA patients, a high frequency (47%) of low BMD in femur as well as in lumbar spine was found. Low BMD was associated with male gender and decreased functional capacity. These findings emphasize the need for more alertness for osteoporosis and osteopenia in spondylarthropathy patients at an early stage of the disease.

The relationship between disease-related characteristics and conduction disturbances in ankylosing spondylitis.

OBJECTIVES: Ankylosing spondylitis (AS) is associated with an increased cardiovascular (CV) risk. Conduction disturbances (CD) may explain the CV burden, as they are independently associated with cardiac disease. The aim of this study was (i) to determine the prevalence of CD in AS, and (ii) to evaluate the relationship between CD and demographic and AS-related characteristics. METHODS: A rheumatological evaluation assessing demographic and AS-related characteristics and a resting standard 12-lead electrocardiogram (ECG) were performed in 131 consecutive AS patients. RESULTS: A first-degree atrioventricular (AV) block was found in six (4.6%) patients. One (0.8%) patient suffered from a complete right bundle branch block (RBBB) and one (0.8%) patient had a left anterior hemiblock. A prolonged QRS (pQRS) interval was observed in 38 (29.2%) patients, including those with a complete or incomplete BBB. Age, disease duration, and body mass index (BMI) were significantly associated with the PR interval, and male gender, disease duration, and the Bath Ankylosing Spondylitis Metrology Index (BASMI) with the QRS interval. In multivariate analyses, disease duration remained independently associated with both the PR and the QRS intervals. CONCLUSION: Intraventricular CD is highly prevalent in AS, particularly in patients with long-standing disease. Further research is needed to determine whether intraventricular CD contribute to the increased CV risk and long-term CV mortality in AS.