Table 3. Correlation between different methylation status of VDAC2 promoter and PR%.

Variables	Correlation coefficient (r)
	Completely unmethylation (0%)	Mild methylation (0–20%)	Moderate methylation (20–80%)
Age	−0.192	−0.163	0.201
PR%	0.48**	0.41**	−0.65**
Density	0.177	−0.024	−0.141
Volume	0.103	0.085	−0.107

PR%: percentage of progressive sperm ratio; *P < 0.05; **P < 0.01.