Table 1.
Characteristics of the study population by body mass index (N=483)
| Body Mass Index (kg/m2) | P | ||||
|---|---|---|---|---|---|
| 18.5 – 24.9 | 25 – 29.9 | 30 – 34.9 | ≥ 35 | ||
| N | 123 | 233 | 87 | 40 | |
| Personal Characteristics | |||||
| Age, years | 35.7 (5.2) | 36.3 (5.2) | 37.2 (5.9) | 35.7 (5.6) | 0.33 |
| Body mass index, k/m2 | 23.0 (1.5) | 27.2 (1.4) | 31.8 (1.3) | 39.4 (5.2) | <0.001 |
| Height, cm | 179.7 (7.4) | 179.0 (7.3) | 179.4 (6.2) | 180.6 (7.0) | 0.64 |
| Caffeine intake, mg/day | 98 (111) | 109 (131) | 130 (153) | 110 (161) | 0.22 |
| Alcohol intake, drinks/day | 0.4 (0.6) | 0.6 (0.8) | 0.5 (0.8) | 0.3 (0.5) | 0.39 |
| Smoking status, % | 0.17 | ||||
| Never smoker | 79.7 | 70.4 | 68.9 | 62.5 | |
| Past smoker | 13.0 | 21.9 | 18.4 | 20.0 | |
| Current smoker | 6.5 | 7.7 | 11.5 | 15.0 | |
| Unknown status | 0.8 | 0 | 1.2 | 2.5 | |
| Race/ethnicity | 0.50 | ||||
| White/Caucasian | 83.7 | 84.1 | 87.3 | 90.0 | |
| Black/African American | 4.9 | 3.9 | 2.3 | 5.0 | |
| Asian | 6.5 | 3.0 | 5.7 | 2.5 | |
| Other | 4.9 | 9.0 | 4.6 | 2.5 | |
| Reproductive history | |||||
| Ever made partner pregnant, % | 39.0 | 40.8 | 48.2 | 37.5 | 0.51 |
| Previous infertility examination, % | 34.9 | 36.1 | 47.1 | 30.0 | 0.18 |
| Testes always in scrotum, % | 98.4 | 94.9 | 92.0 | 90.0 | 0.09 |
| Groin injury, % | 26.8 | 35.2 | 42.5 | 37.5 | 0.12 |
| Reproductive surgery*, % | 5.7 | 6.9 | 6.9 | 0 | 0.39 |
| Semen Analysis | |||||
| Abstinence time, days | 3.9 (2.3) | 4.1 (3.0) | 3.9 (2.7) | 4.9 (5.3) | 0.19 |
| Concentration <20 million/mL, % | 10.6 | 15.0 | 12.6 | 20.0 | 0.43 |
| Motility <50% motile, % | 52.0 | 45.1 | 43.7 | 42.5 | 0.52 |
| Morphology <4% normal, % | 13.8 | 24.4 | 20.7 | 27.5 | 0.09 |
*
Varicocelectomy, orchidopexy or hydrocelectomy.