Bidirectional association identified between synovitis and knee and hand osteoarthritis: a general population-based...

Area of Science:

• Rheumatology
• Epidemiology
• Genetics

Background:

• Osteoarthritis (OA) is a prevalent joint disease.
• Synovitis, joint inflammation, is a common feature of OA.
• Current anti-inflammatory treatments show limited efficacy in OA clinical trials.

Purpose of the Study:

• To investigate the temporal relationship between synovitis and OA.
• To determine if synovitis is a risk factor for OA or a consequence of OA.
• To explore the causal link between synovitis and OA.

Main Methods:

• Prospective cohort study with 3-year follow-up (Xiangya Osteoarthritis Study).
• Assessed ultrasound-detected synovitis and OA using generalized estimating equations.
• Conducted bidirectional Mendelian randomization (MR) analyses using whole-genome sequencing data.

Main Results:

• Baseline synovitis was associated with incident radiographic and symptomatic OA at knee and hand sites.
• Baseline OA was associated with incident synovitis at both sites.
• MR analyses supported a causal, bidirectional association between synovitis and OA (ORs 1.2-1.7).

Conclusions:

• Synovitis and OA have a bidirectional, likely causal relationship.
• Synovitis is both a risk factor and a consequence of OA.
• Findings suggest synovitis plays a complex role in OA pathogenesis.