Association of overweight and obesity with Bell palsy in children. V. Breitling, A. Leha, S Schiller, et al. Pediatric Neurology 2023;139:43-48.
What the researchers did:
Childhood obesity is a substantial and worsening public health problem in the US and many other countries. Obesity not only plays a major role in hypertension, type 2 diabetes, and cardiovascular disease but is also implicated in autoimmune and inflammatory diseases. Bell palsy is a peripheral facial nerve palsy with an acute onset and unknown cause. The disorder accounts for about half of all peripheral facial nerve palsies in childhood. One study in adults has found a positive association between body mass index (BMI) and the occurrence of Bell palsy. However, whether any such association between overweight and Bell palsy exists in children is unknown. To address this issue, a group of researchers in Germany conducted a single-centered retrospective study in which they compared BMIs in patients with Bell palsy and peripheral facial palsy of other origins with a control population from a national child health survey.
What the researchers found:
The investigators identified 99 pediatric patients with Bell palsy and 103 patients with peripheral facial nerve palsies of other etiology (neuroborreliosis, post-surgical, otitis media, infectious, trauma, and inflammatory) over a 10-year period. 38% of the patients with Bell palsy had a BMI above the 90th percentile. 24% of the patients with peripheral nerve palsy of other etiology had a BMI above the 90th percentile. These findings led to a statistically significant association between high BMI and Bell palsy. In contrast, there was no significant association between high BMI and peripheral nerve palsy of other etiology. The researchers found that the risk of developing Bell palsy is increased more than twofold when a child is overweight or obese. They further found that this association was much stronger for boys than for girls, suggesting that the threshold for developing Bell palsy associated with a higher BMI is lower in boys than in girls. Thus, being overweight or obese increases the odds of developing Bell palsy, especially in boys.
What the research means:
The results of this study suggest that being overweight or obese more than doubles the risk that a child will develop Bell palsy. Thus, the spectrum of potential problems for children who are overweight is further increased. The fascinating question that cannot be answered from this retrospective study is why is there an association between obesity and Bell palsy? Because the data for this study were retrospectively gathered and limited in scope, it is not possible to know whether hemoglobin A1c levels, hypertension, or levels of inflammatory markers, which can accompany elevated BMI, were correlated with the odds of developing Bell palsy. Answers to that question could shed considerable light on the biology of obesity and Bell palsy at the same time.