Background Hand osteoarthritis (OA) and its more severe subset erosive hand OA are common causes of pain and morbidity. Some metabolic factors were suggested to be implicated in erosive disease. Furthermore, few studies investigated differences in systemic bone loss and cardiovascular risk factors between erosive and non-erosive hand OA.

Objectives To compare bone mineral density (BMD) and major cardiovascular risk factors between patients with erosive and non-erosive hand OA in a cross-sectional study.

Methods Patients with symptomatic disease fulfilling the American College of Rheumatology (ACR) criteria for hand OA were included in this study. Erosive hand OA was defined by at least one erosive interphalangeal joint. All patients underwent clinical assessments of joint swelling and radiographs of both hands. DEXA examination of lumbar spine, total femur and femur neck was performed. Metabolic risk factors (body mass index, hypertension, diabetes, dyslipidaemia) were collected. Patients were examined at baseline, one-year and two years follow-up.

Results Altogether, 129 patients (12 male) with symptomatic nodal hand OA were included in this study and followed between April 2012 and January 2017. Out of these patients, 72 had erosive disease. The disease duration (p<0.01) was significantly higher in patients with erosive compared with non-erosive disease at baseline. Patients were taking symptomatic slow acting drugs (SYSADOA) twice a year, non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics on demand. Baseline population characteristics did not differ between both groups. Osteoporosis (T-score <-2.5 SD) was diagnosed in 12.5% (9/72) of patients with erosive hand OA and in 8.06% (5/57) of patients with non-erosive hand OA. Although bone mineral density did not significantly differ between the groups, T-scores of lumbar spine (-0.46 vs. -1.04 SD, p<0.001), total femur (-0.36 vs. -1.20 SD, p<0.001) and femur neck (-0.92 vs. -1.20 SD, p<0.01) were significantly lower in patients with erosive compared with non-erosive disease. After two years, the decrease in T- score of lumbar spine was significantly higher in patients with erosive compared with non-erosive hand OA (-0.08 SD vs. 0.07SD, p<0.01; total difference between groups is 10.92%). The decrease of T-score in femur neck, total femur and the decrease of BMD (g/cm²) in all regions were also higher, although not significantly, in patients with erosive compared with non-erosive hand OA. In addition, more patients with erosive compared with non-erosive hand OA were treated for dyslipidaemia at baseline and after two years (32% vs. 28% and 32% vs.30%, p<0.01 for both comparisons).

Conclusions These results suggest that patients with erosive hand OA are at risk for development of general bone loss and cardiovascular diseases.

Acknowledgements This work was supported by the project MHCR No. 023728.

Disclosure of Interest None declared