Bone mineral density in patients with hand osteoarthritis compared to population controls and patients with rheumatoid arthritis.

OBJECTIVES Several studies have revealed increased bone mineral density (BMD) in patients with knee or hip osteoarthritis, but few studies have addressed this issue in hand osteoarthritis (HOA). The aims of this study were to compare BMD levels and frequency of osteoporosis between female patients with HOA, rheumatoid arthritis (RA) and controls aged 50-70 years, and to explore possible relationships between BMD and disease characteristics in patients with HOA. METHODS 190 HOA and 194 RA patients were recruited from the respective disease registers in Oslo, and 122 controls were selected from the population register of Oslo. All participants underwent BMD measurements of femoral neck, total hip and lumbar spine (dual-energy x ray absorptiometry), interview, clinical joint examination and completed self-reported questionnaires. RESULTS Age-, weight- and height-adjusted BMD values were significantly higher in HOA versus RA and controls, the latter only significant for femoral neck and lumbar spine. The frequency of osteoporosis was not significantly different between HOA and controls, but significantly lower in HOA versus RA. Adjusted BMD values did not differ between HOA patients with and without knee OA, and significant associations between BMD levels and symptom duration or disease measures were not observed. CONCLUSION HOA patients have a higher BMD than population-based controls, and this seems not to be limited to patients with involvement of larger joints. The lack of correlation between BMD and disease duration or severity does not support the hypothesis that higher BMD is a consequence of the disease itself.