A Canadian case control study investigating demographic and environmental factors associated with MOGAD

Background: Little is known about demographic and environmental factors associated with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).Objective: To investigate factors associated with MOGAD using a case-control design and validated questionnaire from the Environmental Risk Factors in Multiple Sclerosis Study (EnvIMS).Methods: We enrolled patients with positive MOG antibody serology and diagnosis of MOGAD at six Canadian centres. MOGAD participants completed the EnvIMS questionnaire, and were compared to unaffected controls from the Canadian arm of EnvIMS. We calculated crude and adjusted odds ratios (OR) using logistic regression models and Firth's procedure for rare events.Results: We enrolled 39 MOGAD participants with mean (SD) age 45.0 (14.4) years, 28 (71.8 %) women, 25 (64.1 %) White, 26 (66.7 %) residents of Ontario, and mean BMI 28.6 (7.1). They were compared to 956 controls. Using multivariable logistic regression, larger body size at age 10 years (OR: 3.57, 95 % CI:1.23 - 10.33) and non-White ethnicity (OR:3.81, 95 % CI:1.93-7.54) were associated with higher odds of MOGAD. Among Ontario residents, current BMI >= 30 was associated with higher odds of MOGAD (OR:2.79, 95 % CI:1.03-7.53). Conclusion: Our findings are hypothesis-generating due to the sample size, but suggest that obesity and ethnicity should be explored as potential risk factors for MOGAD in other settings.