Glucose-induced insulin response and insulin sensitivity is not related to HLA-type but to age in young siblings of Type 1 (insulin-dependent) diabetic patients

Glucose-induced insulin response and insulin sensitivity were studied in 32 HLA-identical, 38 haplo-identical and 24 non-identical, islet-cell-antibody-negative, healthy siblings of young Type 1 (insulin-dependent) diabetic patients (age range 10–28 years). No significant differences were obtained between HLA-identical, HLA-haplo-identical siblings and HLA-non-identical siblings in insulin response using an i.v. glucose infusion test even when the insulin sensitivity as estimated by the somatostatin-insulin-glucose infusion test was taken into account. A significant inverse correlation to age was found for both insulin response (r=-0.24, p=0.02) and insulin sensitivity (r=-0.36, p<0.01) in the young siblings studied.