Is there an association between psoriatic arthritis (PsA) and osteoporosis?

Association Between Psoriatic Arthritis and Osteoporosis

Psoriatic arthritis (PsA) is significantly associated with an increased risk of osteoporosis and pathological fractures, with patients having nearly three times higher odds of developing osteoporosis compared to the general population. 1

Epidemiological Evidence

PsA affects approximately 30-33% of patients with psoriasis, with equal prevalence in men and women 2. Recent research has demonstrated a clear link between PsA and bone mineral density (BMD) abnormalities:

• A 2024 study found that among PsA patients, 11.7% had osteoporosis and 33.1% had osteopenia 3
• Male PsA patients showed particularly high rates of osteoporosis (9.3%) and osteopenia (34.3%), even under age 50 3
• A large cross-sectional study of US adults found that PsA patients had significantly higher odds of osteopenia (OR 2.86), osteoporosis (OR 2.97), and pathological fractures (OR 2.35) 1

Pathophysiological Mechanisms

The association between PsA and osteoporosis can be explained by several mechanisms:

• Systemic inflammation: PsA is characterized by high levels of pro-inflammatory cytokines (TNF-α, IL-8, IL-6, IL-1) that activate osteoclasts and promote bone erosion 2
• IL-23/IL-17 pathway dysregulation: This pathway plays a crucial role in both PsA development and bone metabolism 2
• Disease duration: Patients with longer duration of psoriatic disease (mean 17 years) show significantly higher rates of osteopenia/osteoporosis compared to those with shorter disease duration (8.8 years) 4
• Medication effects: Some treatments for PsA may impact bone health 5

Clinical Implications

PsA is associated with specific fracture patterns:

• Vertebral fractures (OR 1.45)
• Pelvic fractures (OR 1.75)
• Femoral fractures (OR 2.07)
• Tibial/fibular fractures (OR 1.60)
• Stress fractures (OR 2.87) 1

Risk Factors for Osteoporosis in PsA

Several factors increase osteoporosis risk in PsA patients:

• Lower body mass index (BMI) 3
• Longer disease duration 4
• More severe disease 6
• Chronic systemic inflammation 5

Management Considerations

While current guidelines on comorbidities in psoriasis do not specifically recommend assessment of bone health 5, the evidence suggests that:

• Early diagnostic evaluation of bone metabolism is necessary in PsA patients, especially those with longer disease duration 4
• BMD testing should be considered for PsA patients, particularly males with low BMI 3
• Prophylactic measures such as vitamin D supplementation and weight-bearing exercises may be beneficial 6
• Treatment of the underlying inflammatory disease with biologics may potentially improve bone health, though long-term studies are needed 6

Conclusion

The evidence strongly supports an association between PsA and osteoporosis. The chronic inflammatory nature of PsA affects bone mineral density through multiple pathways, leading to increased risk of osteoporosis and pathological fractures. Early screening and management of bone health should be considered as part of comprehensive care for PsA patients, especially those with risk factors such as low BMI and longer disease duration.