Association Between Hyperuricemia and Ultrasound‐Detected Hand Synovitis

Objective Although hand synovitis is prevalent in the older population, the etiology remains unclear. Hyperuricemia, a modifiable metabolic disorder, may serve as an underlying mechanism of hand synovitis, but little is known about their relationship. We assessed the association between hyperuricemia and hand synovitis in a large population‐based sample. Methods We performed a cross‐sectional study in Longshan County, Hunan Province, China. Hyperuricemia was defined as a serum urate level >420 μmol/L in men and >360 μmol/L in women. Ultrasound examinations were performed on both hands of 4,080 participants, and both gray‐scale synovitis and the Power Doppler signal (PDS) were assessed using semiquantitative scores (grades 0–3). We evaluated the association of hyperuricemia with hand gray‐scale synovitis (grade ≥2) and PDS (grade ≥1), respectively, adjusting for age, sex, and body mass index. Results All required assessments for analysis were available for 3,286 participants. The prevalence of hand gray‐scale synovitis was higher among participants with hyperuricemia (30.0%) than those with normouricemia (23.3%), with an adjusted odds ratio (aOR) of 1.28 (95% confidence interval [CI] 1.00–1.62). Participants with hyperuricemia also had a higher prevalence of PDS (aOR 2.36; 95% CI 1.15–4.81). Furthermore, hyperuricemia positively associated, both at the hand and joint levels, with the presence of gray‐scale synovitis (aOR 1.27; 95% CI 1.00–1.60 and adjusted prevalence ratio [aPR] 1.26; 95% CI 1.10–1.44, respectively) and PDS (aOR 2.35; 95% CI 1.15–4.79 and aPR 2.34; 95% CI 1.28–4.30, respectively). Conclusion This population‐based study provides more evidence for a positive association between hyperuricemia and prevalent hand synovitis.