Effect of Cannabis Usage on Thyroid Eye Disease

Purpose: The purpose of this study is to investigate the association between cannabis usage and thyroid eye disease (TED) in patients with autoimmune hyperthyroidism. While the association between cigarette smoking and TED is well established, the effect of cannabis on TED is unclear. Methods: This cohort study examined data from TriNetX, an electronic health record platform, for patients with autoimmune hyperthyroidism between December 1, 2003, and December 1, 2023. Primary outcomes were TED presentation (exophthalmos, eyelid retraction, eyelid edema, orbital edema, strabismus, and optic neuropathy) and treatment (teprotumumab, methylprednisolone, tarsorrhaphy, and orbital decompression) in cannabis users, nicotine users, and control patients. Propensity matching was performed to control for characteristics such as age, sex, race, prior thyroidectomy, and/or radio ablation. Relative risk between cohorts was calculated for each outcome in 6-month, 1-year, and 2-year intervals following diagnosis of autoimmune hyperthyroidism. Results: Of 36,186 patients with autoimmune hyperthyroidism, 783 were cannabis users, 17,310 were nicotine users, and 18,093 were control patients without cannabis or nicotine usage. Compared with control patients, cannabis users were more likely to be younger, male, and Black/African American and have anxiety or depression. After propensity matching, cannabis users were 1.9 times more likely to develop exophthalmos (p = 0.03) and 1.6 times more likely to develop any TED presentation (p = 0.049) in the 1-year interval although these differences did not remain statistically significant in the 2-year interval. Conclusions: Cannabis users had a significantly increased risk for TED outcomes in the 1-year interval. Further research is needed to inform TED management.