Table 5. Comparison of the sample size of the studies conducted in Chinese populations.

Studies	Meta-analysis 1*		Meta-analysis 2†		Our study
	Case	Control	Case	Control	Case	Control
Li et al. [15]	59	264	59	264	-	-
Lu et al. [16]	250	300	250	300	-	-
Wu et al. [17]	204	210	204	210	-	-
Fei et al. [18]	56	164	-	-	-	-
Guo et al. [19]	264	437	-	-	-	-
Our study	-	-	-	-	1686	1895
Total	833	1375	513	714	1686	1895

^*The mete-analysis of Gorouhi et al [21].

^†The mete-analysis of Zhang et al [20].