1. Leu72Met and Other Intronic Polymorphisms in the and Genes Are Not Associated with Type 2 Diabetes Mellitus, Insulin Resistance, or Serum Ghrelin Levels in a Saudi Population
- Author
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Khalid Gumaa, Abdirashid M. Shire, Ali Al Qarni, Nagalla S. Das, Muhalab E. Ali, Abdulaziz Al Masaud, Faris Elbahi Joatar, and Hayder A. Giha
- Subjects
0301 basic medicine ,medicine.medical_specialty ,endocrine system diseases ,Endocrinology, Diabetes and Metabolism ,Growth hormone secretagogue receptor ,Population ,Single-nucleotide polymorphism ,Biology ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,03 medical and health sciences ,Endocrinology ,Insulin resistance ,Internal medicine ,Genotype ,medicine ,Allele ,Polymorphism ,education ,education.field_of_study ,lcsh:RC648-665 ,Haplotype ,Diabetes mellitus, type 2 ,medicine.disease ,Ghrelin ,030104 developmental biology ,Receptors, ghrelin ,Clinical Study ,Original Article - Abstract
Background Ghrelin (GHRL), a gastric peptide encoded by the GHRL gene, is known to be involved in energy homeostasis via its G protein receptor, encoded by the growth hormone secretagogue receptor (GHSR) gene. Some studies have shown associations between plasma GHRL levels and GHRL single-nucleotide polymorphisms (SNPs), namely the Leu72Met polymorphism (rs696217 TG), with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), while others have not. The controversies in these associations raise the issue of 'which SNPs in which populations.' The aim of this study was to investigate whether SNPs in GHRL and/or GHSR genes were associated with T2DM, IR, or plasma GHRL levels among Arab Saudis. Methods Blood was collected from 208 Saudi subjects with (n=107) and without (n=101) T2DM. DNA samples from these subjects were analyzed by real-time polymerase chain reaction to genotype five intronic SNPs in the GHRL (rs696217 TG, rs27647 CT, rs2075356 CT, and rs4684677 AT) and GHSR (rs509030 GC) genes. In addition, plasma GHRL levels were measured by a radioimmunoassay. Results None of the SNPs were associated with T2DM, IR, or plasma GHRL levels. The frequencies of the alleles, genotypes, and haplotypes of the five SNPs were comparable between the T2DM patients and the non-diabetic subjects. A large number of the GHRL haplotypes indicates the molecular heterogeneity of the preproghrelin gene in this region. Conclusion Neither the Leu72Met polymorphism nor the other intronic GHRL and GHSR SNPs were associated with T2DM, IR, or GHRL levels. Further investigations should be carried out to explain the molecular basis of the association of the GHRL peptide with T2DM and IR.
- Published
- 2017