Glycaemic profile and cognitive impairment in individuals with diabetes mellitus: A cross-sectional study on HbA1c, random blood glucose, and serum insulin levels

This study aimed to evaluate the association between glycaemic profile, evaluated by glycated hemoglobin (HbA1c), random blood glucose, and serum insulin, and the cognitive impairment in individuals with DM. This cross-sectional study was conducted in a clinical school at a University in Southern Brazil, between March and August 2023. Individuals (≥18 years) with a medical diagnosis of DM were studied. The outcome was cognitive impairment assessed by the Montreal Cognitive Assessment, and the exposures were random blood glucose, HbA1c, and serum insulin. In total, 365 individuals were studied. Cognitive impairment was identified in 67.9% of the participants, and high levels of blood glucose, HbA1c, and blood insulin were found in 41.9%, 55.1%, and 48.2% of the individuals, respectively. There was no association between the glycaemic profile (random blood glucose, HbA1c, serum insulin) and cognitive impairment, before and after adjustment for confounding factors. Sensitivity analyses also showed no association. In conclusion, although there was no association between glycaemic profile and cognitive function, a high prevalence of both cognitive impairment and uncontrolled glycemia was found in individuals with DM. These findings raise questions about the mechanisms involved in DM-related cognitive impairments, highlighting the need for broader investigations to guide public health strategies.