Table 2.

Characteristics and semen parameters in men with different ages (yr)

Parameters	20–25 yr (n = 34)	30–35 yr (n = 37)	40–45 yr (n = 35)	P-value
Age (yr)	24.0 (22.0–25.0)	33.0 (32.0–34.0)	43.0 (42.0–44.0)	0.001a 0.001b 0.001 ${}^c$
BMI (kg/m2)	23.3 (22.5–23.9)	22.9 (22.2–23.6)	23.3 (22.0–23.6)	0.240a 0.343b 0.924 ${}^c$
Semen volume (ml)	4.5 (3.8–5.0)	4.0 (3.5–5.0)	4.0 (3.0–5.0)	0.324a 0.395b 0.729 ${}^c$
Sperm concentration (×106/ml)	82.0 (72.0–85.0)	73.0 (66.5–87.0)	66.0 (60.0–72.0)	0.557a 0.001b 0.003 ${}^c$
Total motility (%)	59.0 (54.0–62.0)	56.0 (52.5–60.0)	52.0 (49.0–58.0)	0.177a 0.006b 0.022 ${}^c$
Normal morphology (%)	14.2 (10.0–17.0)	14.0 (12.7–15.5)	11.0 (9.5–12.5)	0.670a 0.015b 0.001 ${}^c$
Data presented as Median (IQR), Mann-Whitney test was used. BMI: Body mass index. a: Between 20–25 vs. 30–35 yr, b: Between 20–25 vs. 40–45 yr, c: Between 30–35 vs. 40–45 yr