Acute GLP-1 infusion recruits skeletal muscle microvasculature in healthy humans

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 824-833-GI Regulatory Peptides
Bench to Bedside
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-827
Sharmila C Subaran*1, Matthew A Sauder1, Weidong Chai1, Linda Jahn1, Dale E Fowler1, Ananda Basu2 and Zhenqi Liu1
1Univ of Virginia Hlth System, Charlottesville, VA, 2Mayo Clinic, Rochester, MN
Muscle microvascular surface area determines substrate and hormonal exchanges between plasma and muscle interstitium. Glucagon-like peptide-1 (GLP-1), a major incretin produced by the intestinal L-cells in response to nutrient ingestion, regulates glucose-dependent insulin secretion and has numerous extra-pancreatic effects, including a salutary vascular action. The aim of the study was to examine whether GLP-1 increases skeletal muscle microvascular perfusion in healthy humans. Twenty-one overnight-fasted healthy young adults (13M/8F, aged 23.3 ± 0.7 years, BMI 21.91 ± 0.44 kg/m2) were studied at the University of Virginia. Each subject received a GLP-1 infusion at 1.2 pmol/kg/min for 150 min. Forearm skeletal muscle microvascular blood volume (MBV) and microvascular flow velocity (MFV) were evaluated using contrast-enhanced ultrasound at baseline, 30 min and 150 min. The product of MBV and MFV determined microvascular blood flow (MBF). Brachial artery diameter (d) and mean brachial artery blood velocity (v) were measured and brachial artery blood flow (Q) was calculated [Q=vπ*(d/2)2] before and at the end of GLP-1 infusion. GLP-1 infusion significantly increased MBV at 30 min (7.21 ± 0.49 dB, p<0.001) and 150 min (7.38 ± 0.45 dB, p<0.001) when compared to baseline (5.49 ± 0.46 dB) without altering MFV. MBF increased significantly at 30 min (2.80 ± 0.15 dB/sec, p=0.01) and 150 min (2.89 ± 0.15 dB/sec dB, p<0.001) when compared to baseline (2.27 ± 0.18 dB/sec). GLP-1 infusion also significantly increased brachial artery diameter (3.86 ± 0.13 mm, p<0.05) and blood flow (68.4 ± 5.7 ml/min, p<0.05) at 150 min when compared to baseline values (3.64 ± 0.11 mm and 55.4 ± 5.9 ml/min respectively). We conclude that acute GLP-1 infusion significantly recruits muscle microvasculature in healthy humans which could contribute to increased muscle delivery and action of insulin and therefore glycemic control appreciated in GLP-1 receptor agonist treatment in type 2 diabetes mellitus.

Nothing to Disclose: SCS, MAS, WC, LJ, DEF, AB, ZL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm