Аssociation of parameters of energy metabolism and levels of stress hormone cortisol with cognitive characteristics of patients with vascular encephalopathy

Introduction. In patients with vascular encephalopathy (VE), the performance of cognitive tasks may be accompanied by stress and an increase in the level of cortisol affecting the regulation of insulin and glucose metabolism. It is known that an elevated level of cortisol may cause neurodegenerative changes in the hippocampus, and it also can lead to insulin resistance and hyperglycemia, which negatively affects cognitive function.

Objective: to evaluate the association of parameters of cortisol, insulin and glucose levels and their reactivity with the cognitive results in patients with VE.

Methods. Eighty four patients with VE (60 women and 24 men) aged 43–87 years were examined. Patients with type 2 diabetes and metabolic syndrome were excluded from the cohort. All patients performed 3 cognitive tasks (corrective, verbal fluency and verbal memory assessment, the Luria test). Cortisol and insulin in saliva, and glucose in peripheral capillary blood before and after testing of cognitive functions were examined.

Results. In women, the level of salivary cortisol and insulin after the cognitive tasks increased significantly, and the blood glucose level decreased. In men, similar reactive changes of these hormones and glucose were observed, but the changes did not reach statistical significance. In men and women the higher reactivity of cortisol was accompanied by lower, and insulin and glucose by higher results of cognitive performance.

Conclusion. In patients with VE, the cognitive performance is accompanied by reactive changes in cortisol, insulin and glucose levels associated with higher results in cognitive tests.