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Oral glucose challenge impairs skeletal muscle microvascular blood flow in healthy people

Citation

Russell, RD and Hu, D and Greenaway, T and Sharman, JE and Rattigan, S and Richards, SM and Keske, MA, Oral glucose challenge impairs skeletal muscle microvascular blood flow in healthy people, American Journal of Physiology - Endocrinology and Metabolism, 315, (2) pp. E307-E315. ISSN 0193-1849 (2018) [Refereed Article]

Copyright Statement

Copyright 2018 the American Physiological Society

DOI: doi:10.1152/ajpendo.00448.2017

Abstract

Skeletal muscle microvascular (capillary) blood flow increases in the postprandial state or during insulin infusion due to dilation of precapillary arterioles to augment glucose disposal. This effect occurs independently of changes in large artery function. However, acute hyperglycemia impairs vascular function, causes insulin to vasoconstrict precapillary arterioles, and causes muscle insulin resistance in vivo. We hypothesized that acute hyperglycemia impairs postprandial muscle microvascular perfusion, without disrupting normal large artery hemodynamics, in healthy humans. Fifteen healthy people (5 F/10 M) underwent an oral glucose challenge (OGC, 50 g glucose) and a mixed-meal challenge (MMC) on two separate occasions (randomized, crossover design). At 1 h, both challenges produced a comparable increase (6-fold) in plasma insulin levels. However, the OGC produced a 1.5-fold higher increase in blood glucose compared with the MMC 1 h postingestion. Forearm muscle microvascular blood volume and flow (contrast-enhanced ultrasound) were increased during the MMC (1.3- and 1.9-fold from baseline, respectively, P < 0.05 for both) but decreased during the OGC (0.7- and 0.6-fold from baseline, respectively, P < 0.05 for both) despite a similar hyperinsulinemia. Both challenges stimulated brachial artery flow (ultrasound) and heart rate to a similar extent, as well as yielding comparable decreases in diastolic blood pressure and total vascular resistance. Systolic blood pressure and aortic stiffness remained unaltered by either challenge. Independently of large artery hemodynamics, hyperglycemia impairs muscle microvascular blood flow, potentially limiting glucose disposal into skeletal muscle. The OGC reduced microvascular blood flow in muscle peripherally and therefore may underestimate the importance of skeletal muscle in postprandial glucose disposal.

Item Details

Item Type:Refereed Article
Keywords:carbohydrate metabolism, insulin action, metabolic physiology, microvascular blood flow, skeletal muscle
Research Division:Medical and Health Sciences
Research Group:Clinical Sciences
Research Field:Endocrinology
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Diabetes
UTAS Author:Russell, RD (Dr Ryan Russell)
UTAS Author:Hu, D (Mr Donghua Hu)
UTAS Author:Greenaway, T (Dr Tim Greenaway)
UTAS Author:Sharman, JE (Professor James Sharman)
UTAS Author:Rattigan, S (Professor Stephen Rattigan)
UTAS Author:Richards, SM (Dr Stephen Richards)
UTAS Author:Keske, MA (Dr Michelle Keske)
ID Code:127926
Year Published:2018
Web of Science® Times Cited:3
Deposited By:Menzies Institute for Medical Research
Deposited On:2018-08-22
Last Modified:2019-03-04
Downloads:0

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