Table 3. The results of meta-regression in the five genetic models.

Genetic Model	Variables	P for meta-regression
Dominant	year	0.521
	total number of study	0.175
	number of control	0.008
	number of case	0.504
	male (%)	0.152
Recessive	year	0.534
	total number of study	0.738
	number of control	0.013
	number of case	0.530
	male (%)	0.396
Homozygous	year	0.479
	total number of study	0.373
	number of control	0.003
	number of case	0.995
	male (%)	0.347
Heterozygous	year	0.580
	total number of study	0.150
	number of control	0.028
	number of case	0.367
	male (%)	0.152
Additive	year	0.683
	total number of study	0.419
	number of control	0.008
	number of case	0.952
	male (%)	0.116