Our findings are consistent with the study by Rathore et al. [16] but are different from other reports [14, 15, 17] . The potential explanation for the discrepancy may be the limited sample number included in the single study and the relative impact of this polymorphism in the different populations. As shown, the associations were only confirmed in stratified analyses by combining studies with a sample size greater than 200 subjects, which emphasized the importance of having sufficient power with a large enough sample size and the requirement of further largescale analysis.