Association of cognitive dysfunction with hippocampal atrophy in elderly Japanese people with type 2 diabetes

This study aimed to examine the associations of cognitive function with hippocampal and whole brain atrophies, age, education, and diabetes-related parameters in patients with type 2 diabetes.Sixty-one patients over 65 years of age with type 2 diabetes and 53 age- and sex-matched non-diabetic controls were enrolled. Hippocampal and whole brain atrophies were assessed by quantifying hippocampal and brain volumes by brain magnetic resonance imaging. Cognitive function was evaluated by Mini-Mental State Examination (MMSE) and the Revised Hasegawa Dementia Scale (HDS-R).Compared with the non-diabetic group, patients with type 2 diabetes showed significant increases in hippocampal and whole brain atrophies. The MMSE and HDS-R scores in type 2 diabetic patients showed significant negative correlations with age and significant positive correlations with years of education. These scores were also significantly negatively correlated with hippocampal atrophy, but not whole brain atrophy. Hippocampal atrophy in diabetic patients did not, however, correlate with age, years of education, or diabetes-related parameters.We showed hippocampal and whole brain atrophies to be more frequent in elderly patients with type 2 diabetes than in non-diabetic controls. Their cognitive functions were significantly and negatively associated with hippocampal atrophy.