Consultations & Comments: Why the Spotlight on Obesity?

Considering that diabetes is multifactorial, why is there so much discussion in medical circles, as well as in the media, about obesity in children being the cause of the increased incidence of diabetes?

---- Eugene Jura, MD

It is true that both type 1 and type 2 diabetes are multifactorial in etiology, but different factors are involved for each. Type 1 diabetes occurs when the "wrong" genetics interact with the "wrong" trigger, which leads to the development of autoantibodies. These autoantibodies--including GAD-65, ICA, and IAA--attack and destroy beta cells in the islets of Langerhans. This leads to insulin deficiency and the development of hyperglycemia and ketosis. The trigger in type 1 diabetes is not known but is thought to be some sort of viral infection.

Type 2 diabetes also occurs when the "wrong" genetics interact with the "wrong" triggers. In type 2 diabetes, however, the trigger is thought to be aberrant muscle:fat ratio and increased body weight. This leads to peripheral insulin resistance; acanthosis nigricans; increasing insulin levels; and eventual development of hyperglycemia, sometimes with ketosis. Ninety percent of adults with diabetes have type 2 diabetes, while 90% of diabetic children have type 1 disease. The incidence of both type 1 and type 2 diabetes in children has been increasing. The reasons for these increases have not been elucidated, but we suspect that the rise in childhood obesity is a contributing factor in the rising incidence of type 2 diabetes in children.

Obesity is definitely a hot topic in both medical and media circles. This is probably related in part to the value our society places on appearance and thinness. It is also likely that the frequent and lengthy discussions regarding "the growing size of children" is occurring because we, as individuals and as a society, have an opportunity to effect a change. We cannot change genetics or unknown viral triggers. Obesity probably has a multifactorial genetic basis, but it can be affected by changes in food choices and intake as well as by activity level. Therefore, public health interest and interventions focus on the identified and alterable factors that cause childhood obesity.

---- Kathleen C. Moltz, MD Assistant Professor, Pediatrics Pediatric Endocrinology and Diabetes Wayne State University School of Medicine Children's Hospital of Michigan Detroit