Table 2. Associations of FEI With Semen Quality and Biochemistry Parameters of Seminal Plasma Before and After Adjusting for Confounding Factorsa.
| Parameter | All | |||
|---|---|---|---|---|
| Crude | Adjusted | |||
| Effect estimate, % (95% CI)b | P value | Effect estimate, % (95% CI)b | P value | |
| SV | −0.56 (−0.90 to 0.89) | .26 | −0.45 (−0.87 to 1.42) | .42 |
| SC | −0.11 (−0.69 to 1.58) | .81 | −0.01 (−0.66 to 1.91) | .98 |
| TSC | −0.34 (−0.74 to 0.65) | .36 | −0.22 (−0.69 to 1.00) | .60 |
| TSM | −0.99 (−1.00 to −0.98) | <.001c | −0.99 (−1.00 to −0.98) | <.001c |
| PSM | −0.99 (−0.99 to −0.97) | <.001c | −0.99 (−0.99 to −0.98) | <.001c |
| VCL | −0.05 (−0.08 to −0.02) | <.001c | −0.05 (−0.08 to −0.02) | <.001c |
| VSL | −0.07 (−0.10 to −0.04) | <.001c | −0.08 (−0.11 to −0.04) | <.001c |
| VAP | −0.07 (−0.10 to −0.04) | <.001c | −0.08 (−0.11 to −0.04) | <.001c |
| MAD | 0.01 (−0.02 to 0.05) | .47 | 0.02 (−0.01 to 0.05) | .27 |
| Linearity | −0.02 (−0.06 to 0.00) | .09 | −0.03 (−0.07 to 0.00) | .05 |
| Straightness | −0.06 (−0.12 to 0.00) | .09 | −0.07 (−0.13 to 0.00) | .05 |
| Wobble | −0.03 (−0.07 to 0.00) | .10 | 0.00 (−0.08 to 0.00) | .05 |
| ALH | −0.06 (−0.28 to 0.22) | .62 | −0.06 (−0.28 to 0.21) | .60 |
| BCF | 0.52 (0.15 to 1.02) | .003c | 0.57 (0.18 to 1.08) | .002c |
| NSM | −0.98 (−0.99 to −0.93) | <.001c | −0.98 (−0.99 to −0.93) | <.001c |
| DFI | 0.10 (0.06 to 0.14) | <.001c | 0.10 (0.06 to 0.14) | <.001c |
| ACP | 0.00 (−0.01 to 0.01) | .71 | 0.00 (−0.01 to 0.01) | .72 |
| NG | −0.24 (−0.35 to −0.11) | .001c | −0.24 (−0.35 to −0.10) | .001c |
| Fructose | 0.19 (−0.15 to 0.69) | .30 | 0.27 (−0.09 to 0.79) | .16 |
| Zinc | −0.61 (−0.66 to −0.56) | <.001c | −0.61 (−0.65 to −0.56) | <.001c |
Abbreviations: ACP, acid phosphatase; ALH, amplitude of lateral head displacement; BCF, beat cross frequency; DFI, DNA fragmentation index; FEI, formaldehyde exposure index; MAD, mean angular displacement; NG, neutral glucosidase; NSM, normal sperm morphology; PSM, progressive sperm motility; SC, sperm concentration; SV, semen volume; TSC, total sperm count; TSM, total sperm motility; VAP, average path velocity; VCL, curvilinear velocity; VSL, straight line velocity.
a
Confounding factors used in the adjusted model contained age, body mass index, income, smoking status, and alcohol consumption.
b
Effect estimates represent percentage changes in association with a 1-unit increase in FEI.
c
P < .05.