AUTHOR=Huang Rong , Tian Sai , Cai Rongrong , Sun Jie , Shen Yanjue , Wang Shaohua 

TITLE=Ethnicity-Specific Association Between Ghrelin Leu72Met Polymorphism and Type 2 Diabetes Mellitus Susceptibility: An Updated Meta-Analysis

JOURNAL=Frontiers in Genetics

VOLUME=Volume 9 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2018.00541

DOI=10.3389/fgene.2018.00541

ISSN=1664-8021

ABSTRACT=Background: The Leu72Met polymorphism of ghrelin gene has been associated with genetic predisposition to type 2 diabetes mellitus (T2DM), while conclusions remain conflicting. Hence, we performed this updated meta-analysis to clarify the association between Leu72Met polymorphism and T2DM susceptibility.
Methods: Six electronic databases were consulted for articles published before 1 January 2018. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated under five genetic models to assess this association. We used I2 test and Q statistics to measure heterogeneity across the included studies. Subgroup analyses and publication biases were also performed.
Results: Thirteen case-control studies involving 4720 T2DM patients and 4206 controls were included in this meta-analysis. The overall results using fixed-effects models showed that Leu72Met polymorphism was significantly associated with an increased risk of T2DM under homozygous model (OR=1.307, 95%CI 1.001-1.705, p=0.049). Further subgroup analyses stratified by ethnicity revealed that the risk for T2DM was only increased in Asians (homozygous model: OR=1.335, 95%CI 1.014-1.758, p=0.040), while decreased in Caucasians (dominant model: OR=0.788, 95%CI 0.635-0.978, p=0.030; heterozygous model: OR=0.779, 95%CI 0.626-0.969, p=0.025; allelic model: OR=0.811, 95%CI 0.661-0.995, p=0.045). Funnel plots were basically symmetrical, and all p values of Egger’s test under five genetic models were > 0.05, which indicated no evidence of publication bias.
Conclusions: Our results demonstrate that the Leu72Met polymorphism of ghrelin gene may be protective against T2DM in Caucasians, while predisposing to T2DM in Asians.