Transforming growth factor-β genetic polymorphisms on development of liver cirrhosis in a meta-analysis

Transforming growth factor-beta (TGF-beta) protein has been supposed to be a risk factor for liver cirrhosis; however, the associations between its genes (TGF-beta -509C > T and +869T > C) and liver cirrhosis remained unclear. This study was to quantitatively analyze the correlations by using a meta-analysis. Pubmed, Embase, Wanfang databases were retrieved up to November 1st, 2011. Odds ratio (OR) and 95 % confidence interval (95 %CI) were used to demonstrate the strength of association, and P < 0.05 of Z test indicated statistical significance. Combined analyses were performed by using fixed or random-effect model, depending on between-study heterogeneity. Seven studies were for TGF-beta -509C > T polymorphism, and eight studies were for +869T > C polymorphism. Combined results indicated that neither TGF-beta -509C > T nor +869T > C polymorphisms were associated with risk of liver cirrhosis [OR (95 % CI): 0.79 (0.60-1.04) for CT vs. TT of -509C > T and 0.87 (0.68-1.12) for CT vs. CC of +869T > C], with no between-study heterogeneity. In addition, subgroups analyses still inferred that two polymorphisms were not associated with risk of liver cirrhosis for HBV-infected patients, Asians and for Population-based studies. This meta-analysis indicated that neither TGF-beta -509C > T nor +869T > C polymorphisms were associated with risk of liver cirrhosis, regardless of HBV infection or not.