Adenovirus 36 may be associated with obesity

Investigators assessed the relationship between adenovirus 36 (AD36)-specific antibodies and obesity in children to test the hypothesis that this type of viral infection may play a role in the epidemic increase in prevalence of pediatric obesity.

Researchers studied 124 racially and ethnically diverse children from 8 to 18 years of age (median age, 13.6 years). About half the children (54%) had a body mass index (BMI) that would classify them as obese (≥95th percentile); the remainder (46%) were considered nonobese (<95th percentile). All participants provided serum samples that were tested for the presence of AD36-specific neutralizing antibodies.

Nineteen children in the study group tested positive for AD36 antibodies, most (78%) of whom were obese; 22% of the obese children in the entire study group had AD36-specific antibodies compared with 7% of the nonobese children. Further, children who tested positive had a greater median BMI as well as higher values for weight, waist circumference, and waist/height ratio. Children who were AD36 positive were older than children who tested negative; AD36 status did not differ with sex, race, or ethnicity.

Commentary

The obesity epidemic is multifactorial. Each year, we learn about new associations between obesity and TV viewing; about decreased physical activity; about snack food marketing directed at children and the lack of healthy food choice options, especially in "healthy food deserts"; and many others. Could adenovirus infection be another of these factors? This cross-sectional study does show an association between obesity and AD36; however, the investigators are quick to caution against assuming a cause-and-effect relationship. It may be that obesity predisposes to AD36 infection rather than the opposite. And since the AD36- positive obese children were older than the others, it may be that longer life provided more time for exposure to both the virus and poor eating and exercise habits. Animal models, however, seem to support a causal relationship. Look for prospective studies on this topic. One day we may have a vaccine against some types of obesity. -Michael Burke, MD