Muscle strength and bone density in patients with different rheumatic conditions: cross-sectional study

Area of Science:

• Rheumatology
• Bone Health
• Musculoskeletal Research

Background:

• Rheumatic diseases encompass a range of conditions affecting joints and muscles.
• Osteoarthritis and inflammatory arthritis are common forms with distinct pathophysiologies.
• The interplay between muscle strength and bone density in these conditions requires further investigation.

Purpose of the Study:

• To investigate the relationship between muscle strength and bone mineral density (BMD) in patients with various rheumatic diseases.
• To compare the impact of inflammatory arthritis versus degenerative joint diseases on muscle strength and bone loss.

Main Methods:

• 361 patients with rheumatic conditions (osteoarthritis, inflammatory arthritis) underwent assessments.
• Muscle strength was measured using isometric dynamometry (back strength).
• Bone mineral density (BMD) was assessed at the lumbar spine, femoral neck, and distal radius via dual-energy x-ray absorptiometry.

Main Results:

• Patients with hand/shoulder osteoarthritis showed the lowest back strength, followed by those with inflammatory arthritis.
• Inflammatory arthritis patients exhibited the lowest BMD at the mid-radius and femoral neck.
• Lower muscle strength was significantly associated with lower BMD (T score < -1.0) in both sexes.

Conclusions:

• Muscle strength decline is associated with bone loss in patients with rheumatic conditions.
• Inflammatory joint diseases may pose a greater risk for muscle strength reduction and bone loss compared to degenerative conditions.