Specificity of cognitive functions in patients with type 2 diabetes mellitus depending on disease duration

Relevance. In recent years, researchers have increasingly focused on cognitive impairment as a complication of type 2 diabetes, along with cardiovascular disease, nephropathy, and retinal damage. Individuals with type 2 diabetes are 1.5-2 times more likely to develop a wide range of cognitive impairments, including conditions such as vascular dementia and Alzheimer's disease, than the general population. Furthermore, if a patient with this type of diabetes is additionally diagnosed with cognitive impairment, the mortality rate among such patients is 2.4 times higher than among those with the disease but without cognitive impairment. In this regard, studying the specifics of cognitive functions in patients with type 2 diabetes mellitus depending on the duration of the disease is of significant importance in order to provide comprehensive specialized care aimed at treating cognitive disorders.

Purpose: to assess the nature and dynamics of cognitive impairment in patients with type 2 diabetes mellitus and correlate them with the duration of the disease.

Materials and Methods: The study included 103 patients (aged 50-70 years) with T2DM, divided into 4 groups based on disease duration: newly diagnosed (n=18), 1-5 years (n=23), 5-10 years (n=24), and >10 years (n=38). Research methods: theoretical analysis of the literature; Psychodiagnostic methods were used (Montreal Cognitive Assessment (MoCA test); Clock Drawing Test; Schulte Tables; Establishing the Sequence of Events (A.N. Bernstein); Elimination of the Extraneous; Text Retelling). Descriptive statistics, the Mann-Whitney U-test, correlation and regression analysis were used.

Results: A statistically significant progressive decline in overall cognitive status (according to MoCA) was revealed with increasing duration of T2DM (p < 0.01). Impairments in visual-constructive skills and attention were detected already at the early stages. After 5 years of T2DM, attention and speech disorders worsened, and memory and logical thinking deficits were added. With a disease duration of >10 years, a persistent multifunctional cognitive defect developed. Correlation analysis showed a strong inverse relationship between the duration of T2DM and the total MoCA score (r = -0.70; p < 0.01). Analysis of correlation patterns revealed specific cognitive profiles at different stages: from isolated neurodynamic disturbances to complex interactions of deficits.

Conclusions: The duration of type 2 diabetes is a significant predictor of the degree and nature of cognitive dysfunction. These findings support the need for dynamic neuropsychological monitoring and the development of differentiated cognitive rehabilitation programs for patients with varying durations of type 2 diabetes.

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