Relationship between Hba1c Variability and Cognitive Function in Elderly Patients with Type 2 Diabetes

Abstract

Background: Cognitive dysfunction has been noted as a growing complication in type 2 diabetes mellitus especially in the elderly. While average HbA1c is a good tool for evaluating long-term glycemic management, variability in HbA1c from visit-to-visit may offer additional information on the risk of cognitive decline.

Objective: To determine the relationship between HbA1c variability and cognitive function among elderly patients with type 2 diabetes mellitus.

Methodology: The study was analytical cross sectional which involved 89 patients of age 60 years and above, suffering from Type 2 Diabetes Mellitus. The study was conducted at a tertiary care hospital of Pakistan, from January 2025 to June 2025. The HbA1C test results from the past 12 months were reviewed, and the within-patient standard deviation and coefficient of variation were used to evaluate variation. The Montreal Cognitive Assessment (MoCA) was used to assess cognitive function. The participants were divided into two groups: low-HbA1c-variability and high-HbA1c-variability. A correlation analysis and a multivariable logistic regression analysis were used to assess the association between HbA1c variability and cognitive impairment.

Results: The mean age of the participants was 68.74 ± 6.12 years, and 57.3% were male. Cognitive impairment was identified in 42 patients (47.2%). The mean MoCA score was significantly lower among patients with high HbA1c variability than among those with low variability (21.82 ± 4.07 versus 25.07 ± 3.53; p<0.001). Cognitive impairment was more frequent in the high-variability group than in the low-variability group (62.2% versus 31.8%; p=0.006). HbA1c standard deviation showed a significant inverse correlation with MoCA score (r=−0.462; p<0.001). After adjustment for potential confounders, high HbA1c variability remained independently associated with cognitive impairment (adjusted OR: 3.18; 95% CI: 1.29–7.85; p=0.012).

Conclusion: Greater visit-to-visit HbA1c variability was independently associated with poorer cognitive function among elderly patients with type 2 diabetes. Monitoring glycemic fluctuations in addition to average HbA1c may help identify patients at increased risk of cognitive impairment.