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=9

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=<p><bold>Background:</bold> 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.</p><p><bold>Methods:</bold> 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 <italic>I</italic><sup>2</sup>-test and <italic>Q</italic> statistics to measure heterogeneity across the included studies. Subgroup analyses and publication bias were also performed.</p><p><bold>Results:</bold> 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, <italic>p</italic> = 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, <italic>p</italic> = 0.040), while decreased in Caucasians (dominant model: OR = 0.788, 95%CI 0.635–0.978, <italic>p</italic> = 0.030; heterozygous model: OR = 0.779, 95%CI 0.626–0.969, <italic>p</italic> = 0.025; allelic model: OR = 0.811, 95%CI 0.661–0.995, <italic>p</italic> = 0.045). Funnel plots were basically symmetrical, and all <italic>p</italic>-values of Egger's test under five genetic models were &gt;0.050, which indicated no evidence of publication bias.</p><p><bold>Conclusions:</bold> Our results demonstrate that the Leu72Met polymorphism of ghrelin gene may be protective against T2DM in Caucasians, while predisposing to T2DM in Asians.</p>