Table I.
Baseline characteristics of men, from the LIFE study (n = 468).
| Characteristics | BMI |
≥35 (n = 72) | Total | ||
|---|---|---|---|---|---|
| <25 (n = 83) | 25 to <30 (n = 191) | 30 to <35 (n = 122) | |||
| Age (years) n (%) | |||||
| ≤24 | 0 (0.0) | 6 (3.14) | 8 (6.56) | 1 (1.4) | 15 (3.2) |
| 25–29 | 29 (34.9) | 55 (28.8) | 41 (33.6) | 26 (36.1) | 151 (32.3) |
| 30–34 | 31 (37.4) | 70 (36.7) | 41 (33.6) | 31 (43.1) | 173 (37.0) |
| ≥35 | 23 (27.7) | 60 (31.4) | 32 (26.2) | 14 (19.4) | 129 (27.6) |
| Mean (±SD) | 32 (4.8) | 32 (4.8) | 31.4 (4.9) | 31.6 (4.8) | 31.8 (4.8) |
| Self-reported race, n (%) | |||||
| White | 67 (80.7) | 157 (82.2) | 97 (79.5) | 56 (77.8) | 377 (80.6) |
| Others | 16 (19.3) | 34 (17.8) | 25 (20.5) | 16 (22.2) | 91 (19.4) |
| College education, n (%) | |||||
| Yes | 77 (92.8) | 180 (94.2) | 109 (89.3) | 62 (86.1) | 428 (91.5) |
| No | 6 (7.2) | 11 (5.8) | 13 (10.7) | 10 (13.9) | 40 (8.6) |
| Prior paternity, n (%) | |||||
| Yes | 39 (47.0) | 85 (44.5) | 68 (55.7) | 32 (44.4) | 224 (47.9) |
| No | 44 (53.0) | 104 (54.5) | 54 (44.3) | 40 (55.6) | 242 (51.7) |
| WC (cm), n (%) | |||||
| <93.9 | 76 (91.6) | 72 (37.7) | 4 (3.3) | 2 (2.8) | 154 (32.9) |
| 94.0–101.5 | 5 (6.0) | 94 (49.2) | 28 (23.0) | 0 (0.0) | 127 (27.1) |
| ≥101.6 | 0 (0.0) | 25 (13.1) | 89 (73.0) | 69 (95.8) | 183 (39.1) |
| Mean (±SD) | 86.1 (5.1) | 95.9 (8.3) | 105.4 (6.9) | 122.6 (14.5) | 100.8 (14.2) |
| Vigorous physical activity (weekly), n (%) | |||||
| <1 | 52 (62.7) | 102 (53.4) | 72 (59.0) | 44 (61.1) | 270 (57.7) |
| ≥1 | 31 (37.4) | 89 (46.6) | 50 (41.0) | 28 (38.9) | 198 (42.3) |
| Mean (±SD) | 1.1 (1.6) | 1.5 (1.8) | 1.4 (1.8) | 1.5 (2.1) | 1.4 (1.8) |
| Serum cotinine (ng/ml), n (%) | |||||
| ≤9.99 (non-smoker) | 66 (79.5) | 158 (82.7) | 89 (73.0) | 53 (73.6) | 366 (78.2) |
| >10.0 (active smoker) | 17 (20.5) | 31 (16.2) | 29 (23.8) | 19 (26.4) | 96 (20.5) |
| Semen volume (ml), n (%) | |||||
| <1.5 | 4 (4.8) | 22 (11.5) | 11 (9.0) | 11 (15.3) | 48 (10.3) |
| ≥1.5 | 79 (95.2) | 169 (88.5) | 111 (91.0) | 61 (84.7) | 420 (89.7) |
| Median (IQR) | 3.5 (2.4–4.8) | 3.4 (2.1–4.7) | 3.2 (2.3–4.1) | 2.8 (1.8–3.9) | 3.2 (2.2–4.4) |
| Sperm concentration (M/ml), n (%) | |||||
| <15 | 3 (3.6) | 16 (8.4) | 10 (8.2) | 11 (15.3) | 40 (8.6) |
| ≥15 | 80 (96.4) | 175 (91.6) | 112 (91.8) | 61 (84.7) | 428 (91.4) |
| Median (IQR) | 55.3 (34.4–94.1) | 63.2 (38.0–92.5) | 62.4 (31.9–100.4) | 60.0 (25.5–100.4) | 60.8 (34.7–94.7) |
| Total sperm count (M), n (%) | |||||
| <39 | 3 (3.6) | 17 (8.9) | 9 (7.4) | 13 (18.1) | 42 (9.0) |
| ≥39 | 80 (96.4) | 174 (91.1) | 113 (92.6) | 59 (81.9) | 426 (91.0) |
| Median (IQR) | 198.5 (112.8–336.9) | 190.6 (100.3–338.1) | 186.5 (99.1–305.1) | 141.7 (58.4–286.5) | 186.0 (97.8–319.3) |
| Sperm vitality, n (%) | |||||
| <58 | 10 (12.1) | 37 (19.4) | 17 (13.9) | 7 (9.7) | 71 (15.2) |
| ≥58 | 73 (87.9) | 154 (80.6) | 105 (86.1) | 63 (87.5) | 395 (84.4) |
| Median (IQR) | 70.7 (64.8–75.5) | 67.6 (60.1–73.4) | 66.6 (60.3–73.2) | 70.2 (61.7–75.9) | 68.5 (61.7–73.9) |
| Morphology (% WHO normal), n (%) | |||||
| <30% | 36 (43.4) | 88 (46.1) | 51 (41.8) | 33 (45.8) | 208 (44.4) |
| ≥30% | 44 (53.0) | 90 (47.1) | 66 (54.1) | 28 (38.9) | 228 (48.7) |
| Median (IQR) | 31.8 (21.0–39.3) | 30.0 (22.0–39.0) | 32.5 (23.5–40.0) | 29.5 (21.0–37.0) | 30.5 (21.8–39.0) |
| Morphology (% strict criteria), n (%) | |||||
| <4% | 2 (2.4) | 8 (4.2) | 4 (3.3) | 4 (5.6) | 18 (3.9) |
| ≥4% | 78 (94.0) | 170 (89.0) | 113 (92.6) | 57 (79.2) | 418 (89.3) |
| Median (IQR) | 21.3 (12.5–27.5) | 19.3 (12.5–25.5) | 20.5 (14.5–29.0) | 17.0 (12.5–24.0) | 20.0 (13.0–27.0) |
| DNA (% fragmentation index), n (%) | |||||
| <30% | 6 (7.2) | 20 (10.5) | 7 (5.7) | 1 (1.4) | 34 (7.3) |
| ≥30% | 76 (91.6) | 171 (89.5) | 112 (91.8) | 66 (91.7) | 425 (90.8) |
| Median (IQR) | 11.9 (9.1–18.3) | 13.1 (8.6–20.2) | 12.8 (8.2–18.5) | 11.5 (8.1–19.3) | 12.4 (8.5–19.3) |
IQR, interquartile range; WHO, World Health Organization.
We categorized BMI (kg/m2) as <25.0 (underweight and normal), 25.0–29.9 (overweight), 30.0–34.9 (obese, class I) and ≥35 (obese, class II).