PubMed abstract / permitted excerpt

OBJECTIVE: To estimate Bell's palsy incidence and evaluate the prevalence and associations with diabetes and other cardiometabolic conditions. STUDY DESIGN: Population-based cohort study. SETTING: Clalit Health Services, the largest healthcare provider organization in Israel (2005-2022). METHODS: Bell's palsy cases were identified by ICD-10 code G51.0 (n = 11,255). To optimize specificity, individuals with secondary facial palsy codes or competing acute etiologies within ±30 days were excluded. Members without Bell's palsy served as controls. Annual incidence per 100,000 person-years. Multivariable logistic regression adjusted for age, gender, socioeconomic status, and ethnicity; Bonferroni correction applied. Age-stratified and ≥40-year sensitivity analyses were performed. Systemic corticosteroid dispensing was evaluated in peri-index and extended capture windows. RESULTS: Among 5,489,298 members, 11,255 were diagnosed with Bell's palsy (median age, 51 years); about one-third occurred at ages 50 to 69 years. Incidence was ~18 per 100,000 person-years. Diabetes was more prevalent among cases than controls (21% vs 6%; standardized mean difference [SMD] = 0.45) and independently associated with Bell's palsy (adjusted odds ratio [aOR], 1.63), persisting across age groups and in the ≥40-year sensitivity analysis. Diabetic retinopathy and nephropathy were also associated (aOR 1.97 and 1.41). Stroke, smoking and obesity were also independently associated with Bell's palsy. Hypertension was more prevalent among cases but was not independently associated after Bonferroni correction and age-restricted analyses. CONCLUSION: Bell's palsy incidence remained stable throughout the 18-year study period and was associated with diabetes and diabetes-related complications. While current guidelines do not recommend routine HbA1c testing in patients with Bell's palsy, our findings support considering targeted diabetes screening and assessment of glycemic status and diabetes-related complications.