Table 5.
Adjusted linear regression coefficients (95% confidence interval) for change in semen quality or sperm DNA damage measure associated with an interquartile range increase in urinary BPA concentration. Adjusted for specific gravity, age, BMI, abstinence period, current smoking, and time of urine sample.
| 1) BPA measure from same day as semen sample only (n=190)a,d | 2) Geometric Mean BPA from all participants (n=190)b,d | 3) Geometric mean BPA from men with ≥2 BPA measures (n=78)c,d | 4) BPA from same day as semen sample among men with ≥2 BPA measures (n=78)a,d | |||||
|---|---|---|---|---|---|---|---|---|
| β (95%CI) | p-value | β (95%CI) | p-value | β (95%CI) | p-value | β (95%CI) | p-value | |
| Semen Quality | ||||||||
| Sperm Countd,e | 0.85 (0.63, 1.14) | 0.27 | 0.92 (0.66, 1.28) | 0.61 | 1.38 (0.90, 2.12) | 0.14 | 0.93 (0.67, 1.30) | 0.66 |
| Concentrationd,e | 0.77 (0.60, 1.00) | 0.047 | 0.82 (0.62, 1.09) | 0.17 | 1.23 (0.80, 1.92) | 0.33 | 0.87 (0.64, 1.20) | 0.41 |
| Motilityf | -3.70 (-8.12, 0.74) | 0.10 | -2.43 (-7.31, 2.45) | 0.33 | 0.74 (-7.49, 8.97) | 0.86 | -3.92 (-9.98, 2.13) | 0.20 |
| Morphologyf | -0.90 (-1.79, -0.004) | 0.049 | -0.73 (-1.70, 0.26) | 0.15 | -0.84 (-2.55, 0.88) | 0.33 | -1.05 (-2.33, 0.23) | 0.11 |
| Sperm Motion | ||||||||
| VSLf | -1.79 (-4.00, 0.42) | 0.11 | -2.69 (-5.71, 0.35) | 0.08 | -3.78 (-8.75, 1.17) | 0.13 | -3.27 (-6.93, 0.38) | 0.08 |
| VCLf | -3.97 (-7.65, -0.27) | 0.04 | -4.55 (-9.62, 0.54) | 0.08 | -2.85 (-11.5, 5.79) | 0.51 | -5.04 (-11.5, 1.43) | 0.12 |
| LINf | 0.80 (-0.85, 2.44) | 0.34 | -1.17 (-4.26, 1.92) | 0.46 | -0.38 (-5.14, 4.37) | 0.87 | 0.27 (-3.19, 3.73) | 0.88 |
| DNA Damageg | ||||||||
| Comet Extentf | 3.99 (-6.43, 14.4) | 0.45 | 8.11 (-3.98, 20.2) | 0.19 | -4.02 (-23.8, 15.8) | 0.69 | -5.47 (-20.0, 8.95) | 0.45 |
| TDMf | 1.12 (-2.39, 4.63) | 0.53 | 1.13 (-2.93, 5.20) | 0.58 | -3.18 (-9.17, 2.81) | 0.29 | -0.80 (-5.19, 3.60) | 0.72 |
| Tail%f | 3.88 (0.01, 7.74) | 0.048 | 3.65 (0.04, 8.83) | 0.048 | 3.67 (-2.79, 10.1) | 0.26 | 2.88 (-1.73, 7.49) | 0.22 |
Among men with urine sample from same visit as semen sample only. N=190.
Geometric mean of up to 3 repeated urine samples per subject, some of which were collected months after semen sample. N=190.
Geometric mean value among men with at least 2 urine samples. N=78.
Ln-transformations of bisphenol A, total sperm count, and sperm concentration were used. All other variables were modeled untransformed.
Coefficient represents a multiplicative change in sperm concentration for an IQR change in BPA concentration after back-transformation of both sperm concentration and BPA values. For an IQR change in BPA concentration, a coefficient equal to 1.0 indicates no change in sperm concentration, a coefficient < 1.0 indicates a multiplicative decrease in sperm concentration, and a coefficient > 1.0 indicates a multiplicative increase in sperm concentration.
Coefficient represents the change in semen quality parameter or sperm DNA damage measure for an IQR change in urinary BPA concentration after back-transformation of urinary BPA concentration. For an IQR change in BPA concentration, a coefficient equal to 0 indicates no change in semen/sperm measure, a coefficient < 0 indicates a decrease in semen/sperm measure, and a coefficient > 0 indicates an increase in semen/sperm measure.
N=132 for comet assay measures in statistical approaches 1) and 2), N=78 for comet assay measures in approaches 3) and 4).