Table 1 Characteristics, semen parameters, GSTM1, GSTT1 and mtDNAcn in the study population (n = 568).

Age (years)^a

29.61 ± 5.72

BMI (kg/m²)^a

24.74 ± 3.91

Smoking status^b

 Smokers and ever smokers

283 (49.80)

 Non-smokers

285 (50.20)

Alcohol usage^b

 Users

221 (39.50)

 Non-users

339 (60.50)

GSTT1^b

 +

249 (50.30)

 −

246 (49.70)

GSTM1^b

 + 

226 (45.70)

 −

269 (54.30)

GSTT1TM1^b

 –

134 (27.10)

 +−/−+

247 (49.90)

 ++

114 (23.00)

Semen parameters^a

 Semen volume (mL)

3.63 ± 1.40

 Sperm concentration (millions/mL)^c

58.20 (34.00, 91.30)

 Total sperm number (millions)^c

202.90 (111.40, 312.90)

 Progressive motility (%)

48.79 ± 17.77

 Normal morphological (%)^c

2 (1, 4)

 TZI

1.84 ± 1.05

 SDI

1.83 ± 1.42

 Normal acrosome

32.92 ± 19.26

 VCL (µm/s)

57.78 ± 10.71

 LIN (%)

65.71 ± 7.57

 VSL (µm/s)

37.48 ± 7.32

 STR (%)

68.56 ± 9.91

 VAP (µm/s)

49.34 ± 9.26

 WOB (%)

80.04 ± 7.60

 ALH (µm)

2.67 ± 0.60

 BCF (Hz)

5.65 ± 0.98

 MAD (°)

38.68 ± 5.84

 mtDNAcn^c

91.77 (22.05, 493.71)