Cerebral oxygenation in Metabolic Syndrome patients during mental task and muscle metaboreflex activation

Abstract

The post‐exercise muscle ischemia (PEMI) is a well established method to study the cardiovascular adjustments to exercise since it enhances sympathetic tone thereby recruiting the hemodynamic reserves. Thus, PEMI can reveal cardiovascular diseases1,2. Our hypothesis was that, in patients suffering from Metabolic Syndrome (MS), cerebral oxygenation decreased during the metaboreflex elicited by PEMI, because of an exaggerated sympathetic response which could vasoconstrict the cerebral circulation3. Furthermore, we hypothesized that in these patients, the cerebral oxygenation could be further impaired by superimposing a mental task (MT) to PEMI. To this aim, variation in cerebral circulation of MS patients was compared with that of healthy controls during contemporary PEMI and MT.Two groups were enrolled: one composed of 15 subjects (7 women, age 53.5±10.7 yrs.) suffering from MS and a control group (CTL) composed of 14 healthy subjects (6 women, age 50.86±8.2 yrs). Both groups underwent 5 different tests each lasting 12 min: PEMI, control exercise recovery (CER), PEMI+MT, CER+MT, and MT alone. During each session, cerebral oxygenation (COx) was measured by Near Infrared Spectroscopy (NIRS) by applying sensors to the skin of the forehead.Data analysis found no significant differences in COx between groups during any test. No reduction in COx were observed during the PEMI test (CTL 100.9±3.3% vs MS 102.5±1.9%) and the MT test (CTL 101.5±2.2% vs MS 102±1.8%) in both groups. Moreover, the addiction of MT to the PEMI test did not cause any impairment in COx.Contrary to our hypothesis, results of the present study indicate that in patients with MS there is no impairment in COx during sympathetic activation obtained by PEMI. Furthermore, no significant reduction was found in the COx when adding MT to the PEMI test. It was concluded that COx is not impaired in patients suffering from MS when sympathetic tone is augmented.Support or Funding InformationThis study was supported by the “Fondazione di Sardegna”This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.