Association between serum uric acid levels and myasthenia gravis: A meta-analysis

Serum uric acid (UA) levels may be involved in the development of myasthenia gravis (MG) by inhibiting oxidative stress, but the relationship remains unclear. This meta-analysis aimed to assess the association between serum UA levels and MG patients.

According to the established protocol, researchers searched 9 databases for studies on UA levels in MG patients, assessed using the Newcastle-Ottawa Scale. Heterogeneity was evaluated with the I2 statistic and chi-square test. Publication bias was analyzed using funnel plots and Egger test.

This meta-analysis included 9 case-control studies from China, with 2112 participants (955 MG patients, 1157 healthy controls). All studies had Newcastle-Ottawa Scale quality scores of 7 or above. Results showed significantly lower serum UA levels in MG patients compared to controls (I2 = 58%, mean difference [MD]: -43.86, 95% confidence interval [CI]: [-54.98, -32.74], P < .00001). Age differences were identified as a source of heterogeneity, confirmed by subgroup analysis. Subgroup analyses showed that in age-comparable groups, MG and healthy controls had lower heterogeneity in UA levels (I2 = 18%, MD: -36.57, 95% CI: [-44.62, -28.50], P < .00001), and in age-disparate groups (I2 = 0%, MD: -73.78, 95% CI: [-94.13, -53.44], P < .00001). Gender analyses showed UA levels in men (I2 = 69%, MD: -60.29, 95% CI: [-81.75, -38.83], P < .00001) and women (I2 = 1%, MD: -29.80, 95% CI: [-38.03, -21.57], P < .00001).

Lower serum levels of UA are associated with an increased risk of MG, although further large-scale, well-controlled studies are needed to confirm the potential clinical relevance.