A Comparison of Childhood and Adult Type I Diabetes Mellitus

Abstract

The incidence rate of insulin-dependent (Type I) diabetes mellitus is bimodal: one peak occurs close to puberty, and the other in the fifth decade. To evaluate possible differences in these forms of the disease, we examined the clinical, biochemical, autoimmune, and genetic features of 82 children and adolescents (1.3 to 18.2 years old) and 44 adults (20.0 to 55.8 years old) when they presented with Type I diabetes. The mean (+/- SEM) duration of symptoms before diagnosis was longer in the adults (7.5 +/- 1.0 vs. 3.9 +/- 0.4 weeks; P less than 0.001), and their serum C-peptide concentrations at diagnosis were higher (0.29 +/- 0.03 vs. 0.17 +/- 0.01 nmol per liter; P less than 0.001), suggesting that they had more residual beta-cell function. There were no significant differences between the two groups in sex ratio, blood glucose levels, hemoglobin A1 values, degree of metabolic decompensation, or frequency of Type I diabetes in first-degree relatives. Thirty-four of 80 children tested (42.5 percent) were positive for insulin autoantibodies, as compared with only 1 of 26 adults (3.8 percent; P less than 0.001). However, the frequencies of islet-cell autoantibodies were similar in the adults and children (conventional autoantibodies, both 81 percent; complement-fixing autoantibodies, 46.2 percent and 60 percent). More children than adults were heterozygous for both HLA-Dw3/4 antigens (26.6 percent vs. 9.8 percent; P less than 0.05) and HLA-DR3/4 antigens (36.6 percent vs. 12.5 percent; P less than 0.05). We conclude that Type I diabetes that begins in adulthood is characterized by a longer symptomatic period before diagnosis, better preservation of residual beta-cell function, and lower frequencies of insulin autoantibodies and HLA-D3/D4 heterozygosity than Type I diabetes that begins in childhood or adolescence.

Recombinant human preproinsulin expression, purification and reaction with insulin autoantibodies in sera from patients with insulin-dependent diabetes mellitus

“…The ELISA procedure identified six patients (14%) with autoantibodies able to react strongly with recombinant preproinsulin fusion protein. The frequency of IAA in sera from IDDM patients measured with the recombinant ELISA correlated with previously described results (Karjalainen et al, 1989;Wilkin, 1990;Greenbaum et al, 1992). Only five of the IAA positive sera (11.6%) maintained their reaction with recombinant preproinsulin in immunoblotting analysis confirmes the existence of linear antigenic epitopes within the preproinsulin.…”

“…In newly diagnosed IDDM patients the frequency of IAA is about 40% in children, but only 4% in adults (Karjalainen et al, 1989). The IAA may arise secondary to injury of the/3 cells with subsequent release of stored precursors of insulin having antigenic potential.…”

The epidemiology of Type 1 diabetes mellitus is not the same in young adults as in children

“…Our results indicate that caution should be exercised when extrapolating regional differences in incidence of childhood onset Type 1 diabetes to differences in lifelong risk for the disease. To decide whether the higher and increasing incidence rates of childhood Type 1 diabetes in certain countries are due to earlier disease presentation [1,8,9,10] or to an overall increased lifelong risk when compared to countries with lower incidence rates of childhood Type 1 diabetes, it would be necessary to compare incidence rates across countries over even larger age-ranges and longer observation periods.…”

“…Although Type 1 diabetes is commonly considered a disease of children, only a minority of cases actually present in childhood [1,2,17]. We still know remarkably little about the "silent majority" that develop the condition in adult life.…”

“…Adult cases are characterised by a reduced frequency of HLA susceptibility haplotypes, as compared with children [1,16,17], and overall have less acute symptoms than children [1]. Male predominance is a further, unexplained feature of Type 1 diabetes in young adults [18,19,20,21,22,23,24,25,26,27].…”