Decreased cognitive function is associated with preceding severe hypoglycemia and impaired blood glucose control in the elderly individuals with type 1 diabetes

Aim/Introduction This investigation aimed to clarify the relationship between cognitive function and blood glucose control in the elderly individuals with type 1 diabetes. Materials and methods In total, 45 patients with type 1 diabetes, age 74.9 ± 6.7 years, and HbA1c levels of 7.9 ± 0.9% were studied. Severe hypoglycemia occurred in 33% of patients, and the number of severe hypoglycemia episodes was 0.6 ± 1.2 in the past 5 years before the time of the cognitive function tests. We analyzed clinical data and dementia scores on the Revised Hasegawa’s Dementia Scale (HDS-R), Mini-Mental State Examination (MMSE), and Dementia Assessment Sheet for Community-based Integrated Care System, and 21 items (DASC-21). Results There was a significant correlation between HbA1c and HDS-R, MMSE, respectively. There was a significant correlation between the number of severe hypoglycemic episodes and HDS-R, MMSE, and DASC-21, respectively. When the group with experience of severe hypoglycemia was compared to the control group, HDS-R, MMSE, and DASC-21 were meaningfully different after adjusting for age modeling analysis of covariance. Conclusions In elderly individuals with type 1 diabetes, our results suggest that high HbA1c for the past 5 years from the cognitive function test and a history of severe hypoglycemic episodes from the time of disease diagnosis are related to decreased cognitive function.