Influence of childhood type II diabetes on bone formation in the growth period

The influence of childhood type II diabetes on bone formation in the growth period was investigated using the mouse mandible, femur, and tibia. Five-week-old mice with spontaneous type II diabetes (KK-AY) and C57BL/6J mice as a control group were used. Animals were randomly divided into 3 groups, and the regions were excised after 1, 5, and 13 weeks. Regarding the bone length, growth of the femur and tibia was greater in the KK-AY than in the control group, and that of the mandible varied depending on the measurement site. On P-QCT, the trabecular and cortical bone mineral densities of the femur were higher in the KK-AY than in the control group, whereas those of the head of the mandible were higher in the control. The thickness and circumferences around the exosteum and endosteum of the cortical bone were significantly different between the KK-AY and control groups, and X-SSI, Y-SSI, and Polar-SSI of the femur and head of the mandible, were significantly different. The μCT findings were correlated with the p-QCT findings. Bone morphometry clarified that bone formation of long bone at the early age was more active in the KK-AY than in the C57BL/6J group, and bone resorption was promoted with aging in the head of the mandible. These findings suggested that not only the bone length but also bone quality tend to increase in the growth period in childhood type II diabetes.