Association between recovery from Bell's palsy and body mass index

Background: Although many factors have been found to be involved in recovery from Bell's palsy, no study has investigated the association between recovery from Bell's palsy and obesity. This study therefore evaluated the association between recovery from Bell's palsy and body mass index (BMI). Methods: Subjects were classified into five groups based on BMI (kg/m²). Demographic and clinical characteristics were compared among these groups. Assessed factors included sex, age, time from paralysis to visiting a hospital, the presence of comorbidities such as diabetes mellitus and hypertension, degree of initial facial nerve paralysis by House–Brackmann (H-B) grade and neurophysiological testing, and final recovery rate. Results: Based on BMI, 37 subjects were classified as underweight, 169 as normal weight, 140 as overweight, 155 as obese and 42 as severely obese. Classification of the degree of initial facial nerve paralysis as moderate or severe, according to H-B grade and electroneurography, showed no difference in severity of initial facial paralysis among the five groups (P > 0.05). However, the final recovery rate was significantly higher in the normal weight than in the underweight or obese group (P < 0.05). Conclusions: Obesity or underweight had no effect on the severity of initial facial paralysis, but the final recovery rate was lower in the obese and underweight groups than in the normal group.