Is Obesity Related to Processing Speed Impairment in Patients with Multiple Sclerosis: Results of a Large-Scale, Multicenter Study.

BACKGROUND Obesity is linked to greater physical disability and increased comorbidities among patients with multiple sclerosis (MS). Its contribution to cognition in this group is unclear. This observational study examines the link between obesity and processing speed in a large sample of patients with MS (PwMS). METHODS As part of routine clinical care at our center, PwMS completed the Processing Speed Test (PST), an electronic implementation of the Symbol Digit Modalities Test (SDMT). Height and weight were used to calculate body mass index (BMI). Bivariate correlations were conducted to examine the association between PST and BMI in the group overall and in subgroups based on demographic and clinical variables. A one-way ANOVA examined differences in PST by BMI categories (normal weight, overweight, obese). RESULTS The sample included 8,713 patients. No association between PST and BMI was found in the entire sample (r = .01), nor within subgroups based on demographic and disease variables. No difference in PST score was found between BMI categories. CONCLUSIONS No association between BMI and processing speed was found among PwMS regardless of demographic or disease-specific patient characteristics.