Dynamics of peripheral blood flow and microcirculation parameters during the course of memantine and melatonin fixed combination in patients with pre-dementia cognitive impairment and obstructive sleep apnea

Cognitive impairments (CIs) and sleep disorders are the main symptoms in patients with chronic cerebral ischemia, in the development of which dysfunction of the endothelium of the small cerebral vessels plays a key role. Objective. To study the impact of course treatment with a fixed-dose combination of memantine and melatonin on endothelial vasodilator function and functional state of various arterial components in patients with pre-dementia cognitive impairment and obstructive sleep apnea syndrome. Materials and methods. A total of 60 patients were examined (62.9% men; age 55 [51.25; 60] years). Volumetric sphygmography (VS), flow-dependent vasodilation test (FDVT) of the brachial artery (BA) and photoplethysmography (PPG) on the index finger of the right hand were performed. Using the closed-envelope method, 2 groups were formed (n=30). In addition to the current therapy, patients in the study group (SG) were prescribed a fixed combination of 5 mg memantine + 3 mg melatonin at a dose of 2 tablets per day for 28 days. Patients in the control group (CG) received their prior drug therapy. After 28 days, patients in both groups underwent all examination methods again. Results. According to the VS data, a statistically significant decrease in systolic blood pressure (BP) and diastolic BP (DBP) in both upper extremities and DBP in the right leg was observed in patients of the SG compared to patients in the CG after a course of treatment with a fixed-dose combination of memantine and melatonin. According to the FDVT data, there was no reliable improvement in vasomotor function of the endothelium of the elastic muscular vessels. According to the PPG data, a decrease in the stiffness index was noted in the terminal muscular vessels and distributing arterioles. Conclusions. No improvement in vasomotor function of the endothelium of the elastic muscular arteries, terminal muscular arteries and resistance distributing arterioles was observed, which may be caused by the short administration course of the fixed-dose combination of memantine and melatonin. The detected changes in hemodynamic parameters in patients of the study group suggest an associated reduction in the risk of progression of structural and functional disorders of the small arteries and resistance distributing arterioles, worsening of cognitive disorders and a concomitant reduction in cardiovascular risk and mortality.