Table 3.
Adjusted * median difference (95% confidence interval) in semen quality parameters by BMI levels.
| Body Mass Index (kg/m2) | |||||
|---|---|---|---|---|---|
| 18.5 – 24.9 | 25 – 29.9 | 30 – 34.9 | ≥35 | p, trend | |
| Semen Analysis | |||||
| Total sperm count (millions) | ref. | 23 (−22, 68) | −29 (−93, 35) | −86 (−134, −37) | 0.04 |
| Total progressive sperm count (millions) | ref. | 19 (5, 34) | 4 (−14, 21) | −8 (−38, 21) | 0.84 |
| Ejaculate volume (mL) | ref. | −0.5 (−0.8, −0.1) | −0.5 (−0.8, −0.2) | −0.6 (−0.9, −0.2) | 0.01 |
| Sperm concentration (millions/mL) | ref. | 12 (−6, 30) | 5 (−15, 26) | 0.9 (−26, 28) | 0.96 |
| Sperm motility (% motile) | ref. | 7 (2, 14) | 8 (−0.2, 16) | 6 (−3, 16) | 0.15 |
| Sperm morphology (% normal) | ref. | −0.6 (−1.8, 0.7) | 0.3 (−0.9, 1.6) | −1.6 (−3.6, 0.5) | 0.92 |
| Sperm DNA fragmentation | |||||
| Comet extent (μm) | ref. | −2 (−13, 9) | −9 (−20, 3) | 1 (−15, 17) | 0.59 |
| Percent DNA in tail (%) | ref. | −3.1 (−8.7, 2.6) | −4.9 (−11, 1.2) | −1.6 (−9.9, 6.7) | 0.21 |
| Tail distributed moment (μm) | ref. | −1 (−5, 3) | 0 (−5, 5) | 3 (−4, 10) | 0.72 |
| Cells with high DNA damage, (n) | ref. | 1 (−1, 3) | 2 (0.1, 3) | 5 (0.3, 9) | 0.03 |
| Reproductive hormone levels | |||||
| FSH, IU/L | ref. | 0.7 (−0.2, 1.5) | −0.1 (−1.2, 1.0) | −1.6 (−2.6, −0.5) | 0.09 |
| LH, IU/L | ref. | −0.6 (−2.0, 0.8) | −1.1 (−2.7, 0.4) | −1.1 (−3.4, 1.1) | 0.08 |
| Prolactin, ng/mL | ref. | 1.2 (−0.1, 2.6) | −0.2 (−1.6, 1.3) | 2.0 (−0.2, 4.1) | 0.13 |
| Estradiol, pg/mL | ref. | −0.8 (−3.9, 2.2) | 3.6 (−0.8, 7.9) | 4.1 (−0.2, 8.6) | 0.003 |
| Total testosterone, ng/dL | ref. | −56 (−90, −22) | −97 (−133, −61) | −121 (−164, −79) | <0.001 |
| SHBG, nmol/L | ref. | −7.8 (−10.8, −4.8) | −12.5 (−15.7, −9.2) | −15.0 (−20.3, −9.8) | <0.001 |
| T:LH ratio | ref. | −0.1 (−0.2, 0.04) | −0.1 (−0.3, 0.2) | −0.4 (−0.6, −0.2) | 0.01 |
| Inhibin B, pg/mL | ref. | −13 (−26, −1) | −29 (−42, −16) | −59 (−85, −32) | <0.001 |
*
Adjusted for age, race/ethnicity, abstinence time, smoking history, intakes of alcohol and caffeine, history of undescended testes and history of groin injury. Models for reproductive hormones are not adjusted for abstinence time.