title: Changes in vascular responsiveness during a hyperglycemia challenge measured by near-infrared spectroscopy vascular occlusion test.
abstract: Postprandial hyperglycemia is associated with impaired vascular responsiveness. Recent studies have established the use of a near-infrared spectroscopy (NIRS)-derived approach, combined with a vascular occlusion test (VOT), to examine vascular responsiveness within the microvasculature in normoglycemia. The aim of this study was to examine whether this NIRS-VOT technique could detect differences in vascular responsiveness following a hyperglycemic challenge.
  
  
  
  Fourteen young healthy individuals participated in the study. Participants underwent five vascular occlusion tests (pre, 30, 60, 90 and 120min after glucose ingestion). Vascular responsiveness was determined by the slope 2 of oxygen saturation (Slope 2 StO2) and the area under the curve of oxygen saturation (StO2AUC) signal. All individuals had a significant increase in blood glucose concentration after 30min (p<0.001), 60min (p<0.001) and 90min (p<0.01) after glucose ingestion. The Slope 2 StO2increased at 90min (p<0.01) after glucose ingestion. Conversely, The StO2AUCwas significantly decreased 90min following the glucose challenge (p<0.01). A negative correlation was observed between average StO2AUCand average Slope 2 StO2(r=-0.995; p<0.05).
  
  
  
  This study showed that the NIRS-VOT technique is capable of detecting differential changes in vascular responsiveness to a hyperglycemic challenge, as indicated by a steeper Slope 2 StO2and decreased StO2AUCfollowing 90min of an oral glucose challenge.
authors.affiliation: Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada; Coordination for the Improvement of Higher Education Personnel (CAPES), Setor Bancario Norte, Quadra 2 Bloco L, Brasilia, DF 70.040-031, Brazil. Electronic address: rogerio.soares@ucalgary.ca.
authors.forename: Rogério Nogueira
authors.initials: RN
authors.lastname: Soares
authors.affiliation: Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N, Canada.
authors.forename: Raylene A
authors.initials: RA
authors.lastname: Reimer
authors.affiliation: Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Murias
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods*; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D064368:Healthy Volunteers; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D007511:Ischemia; D007866:Leg; D008297:Male; D008833:Microcirculation; D018482:Muscle, Skeletal / Q000098:blood supply*; D010100:Oxygen / Q000097:blood*; D010108:Oxyhemoglobins / Q000378:metabolism; D019518:Postprandial Period; D011237:Predictive Value of Tests; D012372:ROC Curve; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D014111:Tourniquets; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen
keywords: Hyperglycemia; NIRS-VOT; Vascular responsiveness