Cognitive impairment in type 2 diabetes mellitus: prospects for the use of metformin

Abstract

Literature data on epidemiology, mechanisms of development, features of the course of cognitive disorders in type 2 diabetes mellitus (T2DM), as well as prospects for their treatment and prevention were analyzed. Diabetes mellitus is recognized as an independent factor for cognitive impairment and is associated with an increased risk of dementia, the main causes of which are Alzheimer’s disease and vascular dementia. Results of recent research have shown that T2DM due to insulin resistance and a number of other mechanisms accelerates the aging of the brain and the decline of cognitive functions from mild cognitive impairment to dementia, the risk of which is almost doubled. Epidemiological, neuroimaging, and autopsy studies confirm the presence of both cerebrovascular and neurodegenerative mechanisms of brain damage in T2DM. Poor glycemic control is associated with cognitive decline while longer course of diabetes — with deterioration of cognitive functions. According to current guidelines, annual screening is indicated for adults aged 65 and older for early detection of mild cognitive impairment or dementia. The strategy for the treatment and prevention of cognitive impairment in diabetes should be individualized in such a way as to minimize the occurrence of both hyperglycemia and hypoglycemia, and should also be effective in preventing the deve­lopment of vascular complications. Elderly patients with cognitive impairment should have less stringent glycemic goals (such as glycated hemoglobin < 8.0 %). The results of experimental and clinical studies proved that metformin has a whole range of neurospecific properties, which generally prevent the progression of diabetic cerebral disorders and provide a nootropic effect. It has been found that the drug can improve cognitive functions and mood in patients with T2DM, and also prevents the development of dementia, including Alzheimer’s type. The use of metformin allows you to preserve cognitive functions due to a powerful hypoglycemic effect, a low risk of hypoglycemia, as well as a positive effect on other pathogenetic links in the development of diabetic cerebral changes — insulin resistance, hyperinsulinemia, dyslipidemia, inflammation, micro- and macrovascular disorders, which makes it a priority in the treatment of patients with diabetes of any age.

Keywords

• diabetes mellitus
• prediabetes
• insulin resistance
• cognitive disorders
• dementia
• metformin