Bell's palsy: a manifestation of prediabetes?

Background: Idiopathic peripheral facial nerve palsy or Bell's palsy (BP) is the most common cause of facial nerve palsy.

Objective: To evaluate the role of glucose metabolism abnormalities in BP.

Methods: We identified 148 patients with unilateral BP and 128 control subjects. In all we evaluated glucose level at fasting and after a 2-h oral glucose tolerance test (2h-OGTT). In addition we determined insulin resistance (IR), by HOMA-index. Patients and controls were divided in to two groups, according to their Body Mass Index (BMI).

Results: Following a 2h-OGTT, the prevalence of glucose metabolism abnormalities was significantly higher in patients with BP than in controls (P < 0.001). Impaired glucose tolerance (IGT) was found in 57 (38%) patients and in 23 (18%) controls, while a new-diagnosed DM (NDDM) was found in 29 (19%) patients and in 8 (6%) controls. The IR was significantly increased only in BP patients with BMI ≥ 24.9 (P = 0.005). BMI, waist circumference, blood pressure, tryglicerides, serum lipid, drugs use were not significantly different between patients and controls.

Conclusions: In this study we found that prediabetes is frequently associated with facial palsy. We propose to perform a 2h-OGTT in patients with peripheral facial palsy and normal fasting glycaemia. HOMA-index should be evaluated in obese facial palsy patients.