Avoiding the Short- and Long-Term Complications of Juvenile Diabetes
H. Peter Chase MD1
1 Department of Pediatrics, University of Colorado Health Sciences Center, Barbara Davis Center for Childhood Diabetes, 4200 E Nineth Ave., Box B-140, Denver, Co 80262
Type I diabetes (insulin-dependent diabetes mellitus, juvenile diabetes) is by far the most frequent type of diabetes to occur in children and adolescents. The prevalence is approximately 2/1,000 among those less than the age of 20 years in the United States. A second type of diabetes, maturity-onset diabetes in youth, is rare in comparison, is probably inherited as an autosomal dominant trait, and is usually found in overweight teenagers. Type I diabetes results from reduced or absent production of insulin. In patients with maturity-on-set diabetes in youth, insulin production is usually normal or reduced, and C-peptide levels are general low.1
ETIOLOGY
The etiology of type I diabetes is not completely understood but probably involves an interaction between genetic, immunologic, and (viral) infectious factors. Only the order of relative importance assigned to the three has shown change in the past several decades; immunologic factors are considered to have increased from the number three to the number two position in recent years.
Genetic Factors
The human insulin gene is located on the short arm of chromosome 11. The immune response locus (HLA-D) is located on chromosome 6. The genetics of diabetes were previously described as "a geneticist's nightmare." Earlier studies had shown that when type I diabetes developed in one member of a set of identical twins the other twin had a 50% chance of also having the disease.
