Affiliations: Cardiovascular Prevention and Rehabilitation Centre (Centre ÉPIC), Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada | Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada | Department of Medicine, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada | Biostatistics department, Montreal Heart Institute Coordinating Centre and Université de Montréal, Montreal, Quebec, Canada
Note: [] Corresponding author: Mathieu Gayda (Ph.D), Cardiovascular Prevention and Rehabilitation Centre (Centre ÉPIC), Montreal Heart Institute and Université de Montréal, 5055 St-Zotique Street East, Montreal, Quebec H1T 1N6, Canada. Tel.: +1 514 374 1480/Ext 268; Fax: +1 514 374 2445; E-mail: mathieu.gayda@icm-mhi.org
Abstract: We studied the relationship between cardiovascular status (CV) and risk factor numbers, macrovascular (flow mediated dilatation: FMD) and microvascular function using near-infrared spectroscopy (NIRS) in adults with different CV status. Seventy adults with different CV status (27 controls, 18 metabolic syndrome (MetS) and 25 coronary heart disease (CHD) patients) underwent a 5-min forearm arterial occlusion in supine position. High-resolution ultrasound examination of the brachial artery was performed during 1 minute at rest and 45 to 120 seconds after cuff release. Oxy, de-oxy and total hemoglobin signals (O2Hb, HHb and tHb) were measured continuously with NIRS on brachio-radialis muscle. FMD was reduced in CHD patients (P < 0.05) compared to controls. Max. amplitude of O2Hb and Hmax of tHb were reduced (P < 0.05) in MetS patients vs. controls. Post-deflation area under the curve (A.U.C) of O2Hb was lower in CHD (P < 0.01) patients vs. controls and MetS patients. Independent predictors of microvascular function (A.U.C of O2Hb) were abdominal obesity and LDL-cholesterol whereas macrovascular function (FMD) was predicted by CV status. Only A.U.C of O2Hb related to CV risk numbers whereas FMD was not. Although macro and microvascular function were impaired in MetS and CHD patients, microvascular function was more strongly related to CV risk factors.
