Bone mineral density in patients with psoriatic arthritis: data from the Nord-Trøndelag Health Study 3

BACKGROUND The risk of osteoporosis in patients with psoriatic arthritis (PsA) remains unclear. The aim of this study was to compare bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) in patients with PsA and controls. PATIENTS AND METHODS Patients with PsA and controls were recruited from the Nord-Trøndelag Health Study (HUNT) 3. RESULTS Patients with PsA (n=69) and controls (n=11 703) were comparable in terms of age (56.8 vs 55.3 years, p=0.32), gender distribution (females 65.2% vs 64.3%, p=0.87) and postmenopausal status (75.6% vs 62.8%, p=0.08). Body mass index (BMI) was higher in patients with PsA compared with controls (28.5 vs 27.2 kg/m2, p=0.01). After adjusting for potential confounding factors (including BMI), BMD was higher in patients with PsA compared with controls at lumbar spine 1-4 (1.213 vs 1.147 g/cm2, p=0.003) and femoral neck (0.960 vs 0.926 g/cm2, p=0.02), but not at total hip (1.013 vs 0.982 g/cm2, p=0.11). Controls had significantly higher odds of having osteopenia or osteoporosis based on measurements of BMD in both the femoral neck (p=0.001), total hip (p=0.033) and lumbar spine (p=0.033). CONCLUSION Our population-based data showed comparable BMD in patients with PsA and controls. This supports that the PsA population is not at increased risk of osteoporosis.