ABSTRACT
We aimed to define the detailed clinical features of Japanese childhood-onset Type 2 diabetes mellitus [T2DM] patients and to determine whether their discernable characteristics were similar to those of adult- and childhood-onset T2DM in other countries. Research design and methods: Subjects were 22 patients [10 males and 12 females] under treatment without hepatocyte nuclear factor-1alpha or mitochondrial gene mutations and who were diagnosed as diabetic when less than 15 years of age. Results: Body mass indices in boys and girls at onset were 25.8 +/- 6.3 and 24.7 +/- 3.6, respectively, with mean ages of 13.3 +/- 1.7 and 12.8 +/- 2.0 years, respectively. Most patients had a short diabetic duration that required insulin treatment. One or both parents of 18 of the 22 T2DM subjects were diabetic and seven subjects had a history of diabetes in their family over three generations. Conclusion: We demonstrated that a relatively high number of Japanese childhood-onset T2DM cases have a strong genetic factor, and are not necessarily related to excessive obesity. Furthermore, most patients required insulin therapy in the initial stages because of insufficient pancreatic beta-cell reserves. This suggests that malfunction of pancreatic beta-cells triggers hyperglycemia resulting in the requirement for insulin in some Japanese childhood-onset T2DM patients