Table II.
Results of linear mixed models of self-reported BW of LIFE study male participants (n = 427) as a predictor of semen parameters.
| Dependent semen quality variable | Regression coefficient for BW (per 100 grams) [95% CI] | |||||
|---|---|---|---|---|---|---|
| Unadjusted | Adjusted | |||||
| Coeff. | 95% CI | P | Coeff. | 95% CI | P | |
| General characteristics | ||||||
| Volume (ml) | 6.6 | (0.0, 13.2) | 0.05 | 5.2 | (−1.7, 12.1) | 0.14 |
| Sperm concentration (×106/ml) | 0.5 | (−25.1, 26.1) | 0.97 | −2.6 | (−29.6, 24.4) | 0.85 |
| Total sperm count (×106/ejaculate) | 22.2 | (−15.6, 59.9) | 0.25 | 13.8 | (−25.8, 53.4) | 0.49 |
| Hypo-osmotic swollen (%) | 43.4 | (−44.1, 131.0) | 0.33 | −9.6 | (−99.7, 80.6) | 0.83 |
| Sperm motility (24 h) | ||||||
| Average path velocity (mm/s) | 57.4 | (−50.5, 165.3) | 0.30 | 2.1 | (−111.7, 115.9) | 0.97 |
| Straight line velocity (mm/s) | 42.7 | (−45.6, 131.0) | 0.34 | −0.2 | (−93.4, 93.0) | 0.99 |
| Curvilinear velocity (mm/s) | 126.5 | (−60.4, 313.4) | 0.18 | 36.1 | (−161.5, 233.7) | 0.72 |
| Amplitude head displacement (mm) | 3.8 | (−8.2, 15.9) | 0.53 | −1.7 | (−14.3, 10.9) | 0.79 |
| Beat cross frequency (Hz) | 17.5 | (−41.9, 77.0) | 0.56 | 6 | (−56.7, 68.8) | 0.85 |
| Straightness (%) | −33.4 | (−195.4, 128.7) | 0.69 | −112.3 | (−282.7, 58) | 0.20 |
| Linearity (%) | −46 | (−152, 60.1) | 0.39 | −92.9 | (−204.1, 18.3) | 0.10 |
| Percent motility (%) | 13.1 | (−11.5, 37.6) | 0.30 | 1.3 | (−24.4, 27) | 0.92 |
| Sperm head measurements | ||||||
| Length (mm) | −0.3 | (−0.8, 0.2) | 0.21 | −0.3 | (−0.9, 0.2) | 0.23 |
| Area (mm2) | −3.6 | (−11.6, 4.4) | 0.38 | −6.2 | (−14.6, 2.2) | 0.14 |
| Width (mm) | 0.2 | (−1.4, 1.9) | 0.77 | −0.5 | (−2.2, 1.3) | 0.61 |
| Elongation factor (%) | 23.8 | (−26.2, 73.8) | 0.35 | 9.9 | (−43, 62.8) | 0.71 |
| Perimeter (mm) | −2.4 | (−7.0, 2.2) | 0.31 | −3.2 | (−8.1, 1.6) | 0.19 |
| Acrosome area of head (%) | 38.3 | (−7.4, 83.9) | 0.10 | 27.3 | (−20.4, 75.0) | 0.26 |
| Morphology | ||||||
| Strict criteria (%) | 27.7 | (−13.4, 68.7) | 0.19 | 16.6 | (−25.8, 59.1) | 0.44 |
| Traditional normal (%) | 79.2 | (−42.7, 201.0) | 0.20 | 52.9 | (−73.1, 178.9) | 0.41 |
| Amorphous (%) | −2.7 | (−12.7, 7.2) | 0.59 | −2.7 | (−13.3, 7.9) | 0.62 |
| Round (%) | 0.8 | (−4.4, 6.1) | 0.75 | 3.4 | (−2.0, 8.9) | 0.22 |
| Pyriform (%) | −6.1 | (−14.1, 1.9) | 0.14 | −6 | (−14.5, 2.4) | 0.16 |
| Bicephalic (%) | 3.6 | (−1.8, 9.0) | 0.19 | 2.7 | (−3.0, 8.4) | 0.36 |
| Taper (%) | −5.9 | (−12.4, 0.6) | 0.08 | −3.4 | (−10.2, 3.4) | 0.33 |
| Megalo head (%) | −3.9 | (−8.8, 1.0) | 0.12 | −5.3 | (−10.5, −0.1) | 0.05 |
| Micro head (%) | −1.1 | (−5.6, 3.4) | 0.62 | −0.1 | (−4.8, 4.6) | 0.96 |
| Neck/midpiece abnormalities (%) | −2.4 | (−6.0, 1.2) | 0.19 | −1.2 | (−4.9, 2.6) | 0.54 |
| Coiled tail (%) | −0.9 | (−5.2, 3.4) | 0.68 | −0.2 | (−4.6, 4.3) | 0.94 |
| Other tail abnormalities (%) | −3 | (−8.3, 2.3) | 0.27 | −2.9 | (−8.5, 2.6) | 0.30 |
| Cytoplasmic droplet (%) | 2.3 | (−8.3, 13.0) | 0.67 | 2.9 | (−8.3, 14.1) | 0.61 |
| Immature sperm (#) | −2.8 | (−11.2, 5.6) | 0.51 | −2.9 | (−11.8, 6.0) | 0.52 |
| Sperm chromatin stability assay | ||||||
| DNA fragmentation index (%) | −0.7 | (−5.9, 4.5) | 0.78 | 0.5 | (−4.9, 5.9) | 0.85 |
Notes: Findings in boldface are significant (P < 0.05). Adjusted model included age (years), smoking status (unexposed, passive exposure, current smoker), site (MI or TX, USA), race (white non-Hispanic, black non-Hispanic, Hispanic, other) and BMI (kg/m2).