Table II.
Distribution of semen quality parameters by BMI category.
| Characteristic | All subjects | BMI categorya | |||
|---|---|---|---|---|---|
| Underweight (n = 1815) | Normal (n = 22 762) | Overweight (n = 5070) | Obese (n = 302) | ||
| Semen volume, ml | 3.0 (1.9) | 2.6 (1.8) | 3.0 (1.9) | 2.6 (1.8)b | 2.6 (2.0) |
| Sperm concentration, 106/ml | 62.0 (7.0) | 60.0 (15.0)b | 62.0 (7.0) | 62.0 (7.0) | 63.0 (8.0) |
| Total sperm number, 106 | 168.0 (110.0) | 156.0 (95.6)b | 170.0 (110.0) | 163.2 (99.5)b | 166.5 (112.0) |
| Total motility, % | 66.0 (6.0) | 65.0 (7.0) | 66.0 (6.0) | 66.0 (7.0) | 65.0 (6.0) |
| Progressive motility, % | 61.0 (4.0) | 60.0 (8.0) | 61.0 (4.0) | 61.0 (4.0) | 61.0 (4.0) |
| Total motile sperm count, 106 | 107.2 (70.6) | 101.2 (65.3)b | 108.0 (72.5) | 105.1 (66.4) | 109.1 (75.5) |
Data are shown as median (IQR). ‘n’ refers to the number of subjects in each BMI category.
aBMI was categorized using the WHO criteria: underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2) and obese (≥30 kg/m2). The number of underweight, normal weight, overweight and obese subjects were 222, 3046, 660 and 38, respectively. Semen parameters across BMI category were compared using repeated-measures ANOVA followed by Dunnett’s tests.
bCompared with normal, P < 0.05.