Objective To analyze the influence of the high level of blood glucose on the metabolism of brain glucose by comparing the brain PET images of the groups with different level of blood glucose.

Methods Two hundred and thirty-six consecutive patients with high level of blood glucose were divided into two groups by with the history of diabetes mellitus(DM) or not: one hundred and five patients with DM, while one hundred and thirty-one patients without DM.Two hundred and ninety-two healthy people with similar age were selected as a normal control group.All the people were underwent PET/CT imaging.Body mass index (BMI) was counted.The brain imaging was analyzed by the Siemens Scenium software to get and analyze the SUV means(SUV_mean) of the brain zones in the three groups.

Results The BMI between the two groups with high level of blood glucose has no significant difference(t=0.464, P>0.05), while they were higher than that in the normal control group(t=4.742 and 3.244, both P < 0.05).Comparing the cerebral metabolism of the brain zones, the metabolism of calcarine fissure and surrounding cortex were the highest, while the metabolism of mesial temporal lobe and cerebellun were lower.As the blood glucose levels increased, the SUV_mean in the normal control group, the high level of blood glucose group(without DM) and the high level of blood glucose(with DM) were gradually decreased.

Conclusion High level of blood glucose can reduce the metabolism of glucose in the brain, it can be helpful to investigate the pathogenesis of diabetic encephalopathy.