AUTHOR=Yau Adora M. W. , McLaughlin John , Maughan Ronald J. , Gilmore William , Ashworth Jason J. , Evans Gethin H. 

TITLE=A Pilot Study Investigating the Influence of Glucagon-Like Peptide-1 Receptor Single Nucleotide Polymorphisms on Gastric Emptying Rate in Caucasian Men

JOURNAL=Frontiers in Physiology

VOLUME=Volume 9 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2018.01331

DOI=10.3389/fphys.2018.01331

ISSN=1664-042X

ABSTRACT=Gastric emptying rate in humans is subject to large individual variability, but previous research on the influence of genetics is scarce. Variation in the glucagon-like peptide-1 receptor (GLP1R) gene is a plausible candidate gene to partially explain the high variance. This study aimed to investigate the influence of genetic variation in the GLP1R gene on gastric emptying rate of a glucose solution in humans. Forty eight healthy Caucasian males took part in this investigation. Gastric emptying rate of a 6% glucose solution was assessed using the 13C breath test method and a venous blood sample was obtained from each participant. Participants were genotyped for twenty-seven Tag single nucleotide polymorphisms (SNPs) in the GLP1R locus using Sequenom MassARRAY iPLEX GOLD analysis and MALDI-TOF mass spectrometry. 
The time at which maximal emptying rate occurred (Tlag) was faster in participants with the CC genotype than in TT and TC genotypes for SNP rs742764: (Median (quartiles) CC, 35 (30-36) min vs. TT, 43 (39-46) min and TC, 41 (39-45) min; P < 0.01). Tlag was also slower in participants with the AA genotype compared to the TT and TA genotypes for SNP rs2254336: (AA, 43 (39-49) min vs. TT, 36 (34-41) min and TA, 39 (35-42) min; P < 0.05). Analysis by phenotype also showed differences in half-emptying time (T½) and Tlag for SNPs rs9283907, rs2268657 and rs2254336. Several neighbouring Tag SNPs within the GLP1R gene were found to be associated with gastric emptying rate, and should be further investigated.