Table 4. Associations of Formaldehyde exposure index (FEI) with semen conventional parameters before and after adjusting for confounding factors.
| Formaldehyde exposure | Volume (ml)a | Concentration(106/ml)a | Total sperm count(106)a | Sperm progressive motility (PR,%)b | Total motility (PR + NP,%)b |
|---|---|---|---|---|---|
| Crude β coefficients | −0.02 | −0.05 | −0.27 | −0.17 | −0.21 |
| 95% CI | (−0.07,0.02) | (−0.20,0.10) | (−0.72,0.18) | (−0.23,−0.11) | (−0.27,−0.14) |
| P-Value | 0.33 | 0.54 | 0.24 | 0.02* | 0.01* |
| Adjusted β coefficients | −0.02 | −0.02 | −0.20 | −0.19 | −0.23 |
| 95% CI | (−0.08,0.03) | (−0.19,0.14) | (−0.68,0.29) | (−0.25,−0.12) | (−0.30,−0.16) |
| P-Value | 0.43 | 0.77 | 0.38 | 0.01* | 0.004* |
PR: sperm progressive motility equals the spermatozoa moving actively, either linearly or in a large circle, regardless of speed.
NP: non−progressive motility equals all the other patterns of motility with an absence of progression.
Regression coefficients were adjusted for age, cigarette intake, alcohol consumption, body mass index, income, education and abstinence duration.
aResult expressed as the relative percent change for volume, concentration, total sperm count. This number is converted from the antilog of the regression coefficient (β) of the log−linear model.
bFor sperm progressive motility and total motility, result expressed as the absolute change. *P < 0.05.