Obesity is associated with the Optic Neuritis severity in Male patients with Multiple Sclerosis

Background: Obesity is an important modifiable risk factor of MS; a deeper biological understanding of this association is needed. Objective: To evaluate the determinants of acute optic neuritis (AON) severity and recovery in multiple sclerosis (MS). Methods: We included 61 patients with MS with recorded AON severity and recovery according to visual acuity outcomes before, at, and, after the relapse. We measured body mass index (BMI) and the serum concentration of estrogen, leptin, testosterone, sex hormone-binding globulin, and vitamin D. We tested the association between BMI and serum hormones and AON severity and recovery with logistic regressions. Results: In males, moderate/severe AON was associated with higher BMI (31.26 kg/m2 vs 25.73 kg/m2, logistic regression, p= 0.03), higher serum estrogen levels (32.24 nmol/L vs 23.06 nmol/L, logistic regression, p=0.04), and higher serum leptin levels (12.29 ng/mL vs mild AON: 4.1 ng/mL, logistic regression, p=0.06) than mild AON. These observations were not seen in female patients. We did not find an association with BMI or hormone levels and AON recovery. Conclusion: BMI, serum leptin, and serum estrogen were associated with AON severity in male patients but not in female patients. No association of these factors and AON recovery was observed.