Combined mental task and metaboreflex impair cerebral oxygenation in patients with type 2 diabetes mellitus

Abstract

Cardiovascular regulation is altered by type 2 Diabetes Mellitus (DM2), producing an abnormal response to muscle metaboreflex. During physical exercise, cerebral blood flow is impaired in patients with DM2, and this phenomenon may reduce cerebral oxygenation (COX). We hypothesized that the simultaneous execution of a mental task (MT) and metaboreflex activation would reduce COX in DM2 patients. Thirteen individuals suffering from DM2 (6 women) and 13 normal age-matched controls (CTL, 6 women) participated in this study. They underwent 5 different tests, each lasting 12 minutes: post-exercise muscle ischemia (PEMI) to activate the metaboreflex, control exercise recovery (CER), PEMI+MT, CER+MT, and MT alone. COX was evaluated using near infrared spectroscopy with sensors applied to the forehead. Central hemodynamics were assessed using impedance cardiography. We found that when MT was superimposed on the PEMI-induced metaboreflex, patients with DM2 could not increase COX to the same extent reached by the CTL group (101.13±1.08% vs. 104.23±2.51%, p<0.05). Moreover, patients with DM2 had higher mean blood pressure and systemic vascular resistance as well as lower stroke volume and cardiac output levels compared to the CTL group, throughout our experiments. It was concluded that patients with DM2 had reduced capacity to enhance COX when undertaking an MT during metaboreflex. Results also confirm that patients with DM2 had dysregulated hemodynamics during metaboreflex, with exaggerated blood pressure response and vasoconstriction. This may have implications for these patients' lack of inclination to exercise.

Operational Modal Analysis of Near-Infrared Spectroscopy Measure of 2-Month Exercise Intervention Effects in Sedentary Older Adults with Diabetes and Cognitive Impairment

“…Then, the OEF can be altered in older adults with T2DM that can reduce task tolerance [164] where moderate-intensity training has been found helpful [165,166]. T2DM patients have been found to have dysregulated systemic hemodynamics during metaboreflex with an exaggerated blood pressure response and vasoconstriction in muscle [167] and brain [168]. Moreover, studies demonstrated reduced CBF with increasing age as one cause of cognitive impairment [169] as well as altered cerebral metabolism [170].…”

Altered Autonomic Function in Metabolic Syndrome: Interactive Effects of Multiple Components

“…Type 2 diabetes has been shown to significantly modulate muscle metaboreflexinduced peripheral vascular responses by way of enhancing muscle sympathetic nerve activity and the peripheral vasoconstrictor response similar to what is observed in hypertension [16,[95][96][97]. Furthermore, insulin itself, either in the context of diabetes development or via hyperinsulinemia, also exerts an effect on autonomic reflexes, such as the arterial baroreflex [98,99].…”