(C-251) Glucosamine use and its causal effects on intraocular pressure: A Mendelian randomization study

Background: Emerging data suggests that glucosamine use can be associated with increased intraocular pressure (IOP) and could contribute to pathogenesis of glaucoma.

Objectives: We aimed to test for a causal association between glucosamine use and IOP increase. Additionally, we aimed to investigate whether a causal association exists between glucosamine use and primary open-angle glaucoma (POAG).

Methods: A two-sample Mendelian randomization study was performed using the summary statistics of published genome-wide association study (GWAS) data of European descent. Instrumental variables for glucosamine were retrieved from the FinnGen consortium R12 release data (23,751 cases and 477,133 controls). Regarding the IOP measurement and POAG, we used summary level data from GWAS meta-analysis in the European cohorts, reported by Bonnemaijer et al (IOP measurements of 31,269 participants) and Gharahkhani et al (16,677 POAG cases and 199,580 controls) respectively. The primary analyses were performed using the inverse-variance weighted method, and several sensitivity analyses were used.

Results: In two-sample MR analysis, glucosamine use was associated with an increase of IOP (estimated causal effect: 0.49, 95% confidence interval (CI): 0.04-0.94, p = 0.033), and the similar trends were observed in other sensitivity analyses. Regarding the risk of POAG, no significant association was observed (odds ratio = 0.94, 95% CI: 0.70-1.26, p = 0.69).

Conclusions: Glucosamine use can cause an increase in IOP, but whether it leads to glaucoma needs to be further validated.