Relationship between CYP7A1 -204A>C polymorphism with gallbladder stone disease and serum lipid levels: a meta-analysis.

Background: The CYP7A1 gene polymorphism has been reported to be associated with gallbladder stone disease (GSD) and serum lipid levels, but the results were inconsistent. This meta-analysis aimed to evaluate the influence of the -204A>C polymorphism in the promoter of CYP7A1 gene on the GSD and serum lipid levels.
Methods: According to inclusion/exclusion criteria, eligible studies on CYP7A1 gene -204A>C polymorphism of serum lipid levels and the risk of GSD were retrieved. Depending on the between-study heterogeneity, the fixed- or random-effects model was applied, and the data were analyzed using the RevMan software (V5.2).
Results: Five studies totaling 830 GSD patients and 882 healthy controls were used to evaluate the relation of CYP7A1 -204A>C polymorphism with GSD. Overall comparison of alleles A with C in all study population yielded 5% but non-significant increased risk of GSD (OR=1.05, 95% CI: 0.91 - 1.22, P=0.48). Subgroup analysis by ethnic differences did not show any association between CYP7A1 -204A>C polymorphism and GSD either. Four studies totaling 802 cases and 691 controls were used to assess the relation of CYP7A1 -204A>C polymorphism with serum lipid levels. All the subjects were from the Asian population. The pooled effects indicated that AC genotype had higher levels of TG than AA (MD=-0.42, 95% CI: -0.76 - -0.08, P=0.01). CC genotype in cases had higher levels of TC (MD=0.65, 95% CI: 0.25 - 1.05, P=0.001) and LDL-C (MD=0.40, 95% CI: 0.06 - 0.73, P=0.02) than AA, AA (MD = -0.35, 95% CI: -0.60 - -0.10, P=0.007) and AC (MD=-0.35, 95% CI: -0.61 - -0.08, P=0.01) genotypes in controls had higher levels of TC than CC, and AA genotype in controls had higher levels of HDL-C than CC (MD = -0.15, 95% CI: -0.21 - -0.09, P<0.00001).
Conclusions: The CYP7A1 -204A>C polymorphism is significantly associated with serum lipid levels in Asian population, but not gallbladder stone disease.