GA to HbA1C ratio, but not HbA1C is associated with cognition in Chinese nondiabetic old adults

Objectives: To investigate the relationship between glycated albumin (GA) to glycated hemoglobin (HbA1c) ratio and cognitive impairment in old age. Diabetes is associated with cognitive impairment in older people. However, the link between elevated GA/HbA1c levels and the risk of cognitive impairment in nondiabetic individuals is unclear. Methods: A cross-sectional study of 474 old, nondiabetic adults (192 women, mean age 73.8years +/- 6.9 SD) who had been admitted to our hospital was conducted. Glycemic measures included fasting plasma glucose (FPG), 2-hour post-prandial plasmic glucose (2hPPG), GA and HbA1c. Cognitive function was assessed using Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) at the same examination visit in which the glycemic measures were determined. Results: When the individuals were divided into two groups according to the median of GA/HbA1c ratio, old adults with GA/HbA1c ratio >= 2.53 showed lower MMSE and MoCA scores compared to those with GA/HbA1c ratio < 2.53. Univariate regression analysis showed that MMSE and MoCA scores were not correlated with HbA1c, but were inversely correlated with GA and GA/HbA1c ratio. Linear regression analysis revealed that there was a significant negative correlation between GA/HbA1c and cognitive function (beta = -0.77, P < 0.01 for MoCA and beta = -0.69, P < 0.05 for MMSE) even after adjustment for age, body mass index, systolic blood pressure, lipoprotein(a) and sex. Conclusion: Our results indicate that even in the absence of manifest type 2 diabetes mellitus, GA/HbA1c ratio levels exert a negative influence on cognition and it may be a better predictor for cognitive impairment in the older population.