Table III.
Characteristic | Category | Volume <1.5 ml, n (%) | Concentration <15 M/ml, n (%) | Sperm count <39 M, n (%) | Vitality <58% n (%) | WHO normal morphology <30%, n (%) | Strict morphology < 4%, n (%) | DFI > 30%, n (%) |
---|---|---|---|---|---|---|---|---|
BMI (kg/m2) | <25.0 | 8 (5.03) | 9 (5.66) | 9 (5.66) | 25 (15.72) | 36 (45.00) | 2 (2.50) | 6 (7.32) |
25.0–29.99 | 33 (9.59) | 27 (7.85) | 24 (6.98) | 67 (19.48) | 88 (49.44) | 8 (4.49) | 20 (10.47) | |
30.0–34.99 | 19 (8.92) | 17 (7.98) | 17 (7.98) | 40 (18.78) | 51 (43.59) | 4 (3.42) | 7 (5.88) | |
≥35.0 | 19 (15.20) | 21 (16.80) | 24 (19.20) | 16 (13.11) | 33 (54.10) | 4 (6.56) | 1 (1.49) | |
P-trend* | 0.033 | 0.028 | 0.005 | 0.791 | 0.549 | 0.252 | 0.035 | |
Waist circumference (cm) | <93.99 | 19 (6.62) | 17 (5.92) | 16 (5.57) | 53 (18.47) | 65 (44.52) | 5 (3.42) | 9 (5.88) |
94.0–101.59 | 26 (11.35) | 17 (7.42) | 15 (6.55) | 42 (18.34) | 62 (50.82) | 5 (4.10) | 16 (12.70) | |
≥101.6 | 34 (10.73) | 38 (11.99) | 41 (12.93) | 48 (15.29) | 79 (47.88) | 8 (4.85) | 9 (5.08) | |
P-trend* | 0.099 | 0.025 | 0.008 | 0.459 | 0.479 | 0.377 | 0.882 | |
Vigorous weekly activity | <1 | 56 (11.64) | 44 (9.15) | 51 (10.60) | 87 (18.16) | 116 (46.03) | 10 (3.97) | 19 (7.17) |
≥1 | 23 (6.39) | 30 (8.33) | 23 (6.39) | 61 (16.99) | 92 (50.00) | 8 (4.35) | 15 (7.73) | |
P-trend* | 0.053 | 0.64 | 0.422 | 0.8 | 0.287 | 0.972 | 0.532 |
Each semen end-point was dichotomized as normal/abnormal according to WHO standard.
Semen parameters dichotomized per WHO 5th edition.
*P-values of trend test based on linear models. In particular, linear mixed effects models were used for end-points measured in two semen samples, including volume, concentration, motility, total sperm count and vitality, while linear regression models were used for % WHO normal and the DFI. All models adjusted for age (≤24, 25–29, 30–34, ≥35 years), college education (yes/no) and serum cotinine (non-smoker/active smoker).