Clinical characteristics of non-obese children with type 2 diabetes mellitus without involvement of β-cell autoimmunity.

Abstract Aims We examined the clinical characteristics of non-obese Japanese children with type 2 diabetes mellitus (T2DM) not associated with β-cell autoimmunity. Methods Of 218 children who were diagnosed as having T2DM by a school urine glucose screening program in Tokyo, 24 were identified as being non-obese and were enrolled in this study. None of the children had any evidence of β-cell autoimmunity or genetic disorders. Results The mean ages at diagnosis and at the study were 12.5 ± 1.7 and 22.4 ± 5.7 years, respectively. Females were predominant (M/F ratio: 4/20). Family history of T2DM, mostly of the non-obese type, was present in 62.5% of the cases. In regard to the birth weight, 20.8% had a history of low birth weight, and 8.3% were large for gestational age. The mean fasting insulin level, HOMA-R, HOMA-β, and an insulinogenic index on the OGTT at the time of diagnosis were 11.8 ± 7.8 μU/ml, 5.4 ± 3.8, 96.1 ± 55.0 and 0.16 ± 0.14, respectively. Most patients were treated by either oral hypoglycemic drug (45.8%) or insulin (50.0%) therapy at the study, with the mean interval to the start of pharmacological treatment of 3.1 ± 2.3 years. Conclusions Non-obese children with T2DM seemed to show lower insulin secretory capacities with mild, but evident, insulin resistance even from the time of diagnosis, and also earlier requirement of pharmacological therapies during the clinical course. Some genetic factors not associated with autoimmunity may play a role in the etiology of T2DM in non-obese children.