To investigate the association of alternative glycemic measures-namely, serum glycated albumin (GA), hemoglobin A (HbA ), and the GA/HbA ratio-with global brain and hippocampal atrophy in a general elderly Japanese population.
1,278 Japanese subjects aged ≥65 years in a community participated in brain magnetic resonance imaging (MRI) scanning and screening examination of health status in 2012. We measured total brain volume (TBV), hippocampal volume (HV), and intracranial volume (ICV) using the data from the MRI examination. The association of each glycemic measure with the ratios of TBV/ICV (an indicator of global brain atrophy) and HV/ICV (an indicator of hippocampal atrophy) was examined by analysis of covariance.
The mean values of the TBV/ICV and HV/ICV ratios decreased significantly with elevating serum GA levels and GA/HbA ratio levels (all P for trend <0.05), but not with higher HbA levels, after adjusting for age, sex, low education, systolic blood pressure, antihypertensive medication, diabetes mellitus, serum total cholesterol, electrocardiogram abnormalities, body mass index, smoking habits, alcohol drinking habits, and regular exercise. These significant associations were still observed in the sensitivity analysis after excluding subjects with mild cognitive impairment and dementia. In addition, increased serum GA levels and the GA/HbA ratio levels, but not HbA , were closely associated with lower mean values of the TBV/ICV and HV/ICV ratios, irrespective of the presence or absence of diabetes mellitus.
The present study suggests that higher serum GA and higher GA/HbA ratio are significantly associated with global brain and hippocampal atrophy.

© 2020 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.