NADPH oxidase p22phox C242T polymorphism and ischemic cerebrovascular disease: an updated meta-analysis

A growing number of studies on the associations between nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p22phox C242T polymorphism and risk of ischemic cerebrovascular disease have recently been published, but the results remain inconsistent.

We performed an updated meta-analysis to evaluate this association. Eight case-control studies were included, involving 2045 cases and 2102 controls. Heterogeneity was assessed by the Q test and the I2 statistic. Begg and Egger's tests were conducted to evaluate publication bias. Odds ratio (OR) was tested to identify the associations.

Significant associations between p22phox gene C242T polymorphism and ischemic cerebrovascular disease (ICVD) risk were observed in the allelic genetic model (OR=1.33, 95% confidence interval [CI] 1.00-1.77, p=0.048). No statistical significant association was found in the dominant model (OR=0.74, 95% CI 0.54-1.02, p=0.064) and recessive model (OR=1.40, 95% CI 0.89-2.19, p=0.146). Subgroup analysis showed an association in European populations for recessive model (OR=2.13, 95% CI 1.06-4.26, p=0.034) and no significant evidence of association in Asian populations was found (dominant model: OR=0.64, 95% CI 0.41-1.00, p=0.05; recessive model: OR=0.98, 95% CI 0.53-1.81, p=0.948; allelic model: OR=1.51, 95% CI 0.98-2.32, p=0.061).

p22phox gene C242T polymorphism was associated with ICVD risk in the allelic genetic model, as well as in European populations for recessive model. No evidence showed association between p22phox gene C242T polymorphism and ICVD risk in the dominant model and recessive model. Furthermore, no association existed in Asian populations for any of the 3 genetic models and European populations in the dominant model and allelic model.