Gastric inhibitory polypeptide receptor: association analyses for obesity of several polymorphisms in large study groups.

Abstract

BACKGROUND:

Gastric inhibitory polypeptide (GIP) is postulated to be involved in type 2 diabetes mellitus and obesity. It exerts its function through its receptor, GIPR. We genotyped three GIPR SNPs (rs8111428, rs2302382 and rs1800437) in German families with at least one obese index patient, two case-control studies and two cross-sectional population-based studies.

METHODS:

Genotyping was performed by MALDI-TOF, ARMS-PCR and RFLP. The family-study: 761 German families with at least one extremely obese child or adolescent (n = 1,041) and both parents (n = 1,522). Case-control study: (a) German obese children (n = 333) and (b) obese adults (n = 987) in comparison to 588 adult lean controls. The two cross-sectional population-based studies: KORA (n = 8,269) and SHIP (n = 4,310).

RESULTS:

We detected over-transmission of the A-allele of rs2302382 in the German families (pTDT-Test = 0.0089). In the combined case-control sample, we estimated an odd ratio of 1.54 (95%CI 1.09;2.19, pCA-Test = 0.014) for homozygotes of the rs2302382 A-allele compared to individuals with no A-allele. A similar trend was found in KORA where the rs2302382 A-allele led to an increase of 0.12 BMI units (p = 0.136). In SHIP, however, the A-allele of rs2302382 was estimated to contribute an average decrease of 0.27 BMI units (p-value = 0.031).

CONCLUSION:

Our data suggest a potential relevance of GIPR variants for obesity. However, additional studies are warranted in light of the conflicting results obtained in one of the two population-based studies.

• Authors: Carla I G Vogel, André Scherag, Günter Brönner, Thuy T Nguyen, Hai-Jun Wang, Harald Grallert, Alexa Bornhorst, Dieter Rosskopf, Henry Völzke, Thomas Reinehr, Winfried Rief, Thomas Illig, H-Erich Wichmann, Helmut Schäfer, Johannes Hebebrand, Anke Hinney
• Journal: BMC medical genetics (BMC Med Genet) Vol. 10 Pg. 19 (Mar 02 2009) ISSN: 1471-2350 [Electronic] England
• PMID: 19254363 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Validation Study)

Chemical References

• Receptors, Gastrointestinal Hormone
• gastric inhibitory polypeptide receptor

Topics

• Adolescent
• Adult
• Body Mass Index
• Case-Control Studies
• Child
• Cross-Sectional Studies
• Female
• Genetic Predisposition to Disease
• Genotype
• Germany
• Humans
• Male
• Middle Aged
• Obesity (genetics)
• Polymorphism, Single Nucleotide
• Receptors, Gastrointestinal Hormone (genetics)
• Young Adult