Association between 3801T>C polymorphism of CYP1A1 and idiopathic male infertility risk: a systematic review and meta-analysis.
BACKGROUND
Epidemiological studies have evaluated the association between 3801T>C polymorphism of CYP1A1 gene and the risk for idiopathic male infertility, but the results are inconclusive. We aimed to derive a more precise estimation of the relationship by conducting a meta-analysis of case-control studies.


METHODS
This study conformed to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase and CNKI databases were searched through November 2013 to identify relevant studies. Pooled odds ratios with 95% confidence intervals were used to assess the strength of the association between CYP1A1 3801T>C polymorphism and idiopathic male infertility risk. Q-test was performed to evaluate between-study heterogeneity and publication bias was appraised using funnel plots. Sensitivity analyses were conducted to evaluate the robustness of meta-analysis findings.


RESULTS
Six studies involving 1,060 cases and 1,225 controls were included in this meta-analysis. Overall, significant associations between 3801T>C polymorphism and idiopathic male infertility risk were observed in allelic comparison (OR = 1.36, 95% CI: 1.01-1.83), homozygous model (OR = 2.18, 95% CI: 1.15-4.12), and recessive model (OR = 1.86, 95% CI: 1.09-3.20), with robust findings according to sensitivity analyses. However, subgroup analyses did not further identify the susceptibility to idiopathic male infertility in all comparisons. Funnel plot inspections did not reveal evidence of publication bias.


CONCLUSIONS
The current meta-analysis provides evidence of a significant association between CYP1A1 3801T>C polymorphism and idiopathic male infertility risk. Considering the limitation inherited from the eligible studies, further confirmation in large-scale and well-designed studies is needed.
Center of Oncology, The Affiliated Hospital of Guangdong Medical College, Zhanjiang, China.
Haiqing
H
Luo
Department of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang, China.
Hongjiao
H
Li
Department of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang, China.
Na
N
Yao
Department of Epidemiology and Health Statistics, School of Public Health, Guangdong Medical College, Zhanjiang, China.
Liren
L
Hu
School of Public Health, Guangdong Medical College, Zhanjiang, China.
Taiping
T
He
D000483:Alleles; D016022:Case-Control Studies; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics*; D017594:Publication Bias; D012306:Risk
C569463:CYP1A1 protein, human; D019363:Cytochrome P-450 CYP1A1