The Impact of Childhood Obesity on Adult T1D, Other Autoimmune Conditions

Childhood obesity increases the risk for autoimmune diseases, such as type 1 diabetes (T1D), later in life, according to a recent review.

The researchers, writing in the Journal of Internal Medicine, said the risk can be modified by weight reduction, but that the effect appears to be dependent on the age at which weight loss occurs, as well as the specific disease.

According to the World Health Organization, childhood obesity is one of the most serious challenges of the 21st century, with more than 100 million children having obesity.

During childhood, almost all organs are at risk of being affected by obesity, which is implicated not only in T1D but also type 2 diabetes, multiple sclerosis, Crohn disease, arthritis, asthma, cardiovascular disease, and nonalcoholic fatty liver disease, among others.

Consequently, childhood obesity increases the risk for premature mortality.

According to the report, obesity affects the immune system directly and indirectly, with direct effects stemming from immunological changes in the adipose tissue, and indirect effects from endocrinological alterations.

When a child has obesity, chronic low-grade inflammation takes place as fat cells in adipose tissue enlarge, increasing cytokines, macrophages, and lymphocytes. In the context of T1D, it has been proposed that obesity induces insulin resistance. However, the linkl between obesity and T1D is complex and is influenced by genetic factors.

Obesity-induced inflammation may increase the risk of developing T1D with only 1 type of autoantibody present, and may further drive a shift from 1 to 2 autoantibodies in childhood and adolescence. However, this only occurs in specific genetic groups.

"The effects of early childhood obesity on immunological processes and the development of autoimmune diseases are relatively recently clarified and our understanding of mechanisms and how to prevent these diseases are still limited," the authors wrote.

The authors assert that, as the associations between obesity and disease are found before puberty, early treatment of obesity is required to reduce the incidence of immunological-related diseases.

While the risks associated with childhood obesity are modified by weight loss, the risk reduction is affected by the age that weight loss occurs. The report indicates that effect of weight loss on future disease risk seems is also disease dependent. In general, weight loss before puberty is more beneficial, but there are disease-specific differences.

The authors cautioned that as weight loss in children and adolescents is difficult, and treatments that were in effect decades ago were limited and often not effective, any links between weight loss and long-term comorbidities must be handled carefully and studied further.

Reference

Marcus C, Danielsson P, Hagman E. Pediatric obesity–long-term consequences and effect of weight loss. J Intern Med. Published online July 26, 2022. doi:10.1111/joim.13547