Table 4.
Coefficients (95% CIs) from linear regression of PM2.5 exposure during 0 - 90 days before semen collection in relation to semen parameters in all participants (n = 1554)
| Semen parametera | Quintile of PM2.5 exposure (range) | P trendb | ||||
|---|---|---|---|---|---|---|
| Q1 (28.7-49.6) | Q2 (49.7-57.0) | Q3 (57.1-64.8) | Q4 (64.9-74.0) | Q5 (74.1-92.1) | ||
| Semen volume (ml) | 0 (reference) | 0.005 (−0.07, 0.08) | −0.04 (−0.13, 0.04) | −0.07 (−0.17, 0.01) | −0.03 (−0.11, 0.06) | 0.583 |
| Sperm concentration (106/ml) | 0 (reference) | 0.12 (−5.11, 5.36)) | 2.53 (−3.33, 8.39) | −2.18 (−8.18, 3.82) | −0.96 (−6.92, 5.00) | 0.862 |
| Total sperm number (106) | 0 (reference) | 0.03 (−0.11, 0.17) | 0.06 (−0.10, 0.22) | −0.07 (−0.24, 0.09) | −0.04 (−0.21, 0.12) | 0.583 |
| Total motility (%) | 0 (reference) | −6.21 (−9.33, −3.08) | −4.98 (−8.48, −1.48) | −7.00 (−10.58, −3.41) | −8.42 (−11.98, −4.86) | < 0.001 |
| Progressive motility (%) | 0 (reference) | −5.04 (−7.76, −2.31) | −3.74 (−6.79, −0.69) | −4.69 (−7.82, −1.57) | −7.41 (−10.52, −4.30) | < 0.001 |
| VCL (μm/s) | 0 (reference) | −0.03 (−1.46, 1.40) | −1.38 (−2.98, 0.22) | −1.18 (−2.82, 0.46) | −3.24 (−4.82, −1.61) | < 0.001 |
| VSL (μm/s) | 0 (reference) | −0.005 (−0.04, 0.03) | −0.01 (−0.05, 0.03) | −0.01 (−0.05, 0.03) | −0.07 (−0.11, −0.03) | < 0.001 |
| VAP (μm/s) | 0 (reference) | −0.21 (−1.20, 0.77) | −0.37 (−1.47, 0.73) | −0.47 (−1.60, 0.66) | −2.27 (−3.39, −1.15) | < 0.001 |
| BCF (Hz) | 0 (reference) | −0.002 (−0.02, 0.02) | −0.02 (−0.04, 0.003) | −0.03 (−0.06, −0.01) | 0.01 (−0.01, 0.04) | 0.611 |
| ALH (μm/s) | 0 (reference) | 0.01 (−0.04, 0.06) | −0.02 (−0.07, 0.03) | −0.03 (−0.09, 0.02) | −0.06 (−0.11, −0.003) | 0.028 |
| LIN (%) | 0 (reference) | −0.46 (−1.69, 0.76) | 0.78 (−0.59, 2.16) | 0.83 (−0.58, 2.24) | −0.37 (−1.77, 1.03) | 0.971 |
| STR (%) | 0 (reference) | 0.001 (−0.01, 0.01) | 0.005 (−0.004, 0.01) | 0.01 (−0.01, 0.02) | −0.003 (−0.01, 0.01) | 0.862 |
| WOB (%) | 0 (reference) | −0.42 (−1.46, 0.63) | 0.56 (−0.61, 1.73) | 0.61 (−0.59, 1.81) | −0.22 (−1.42, 0.97) | 0.986 |
| MAD (°) | 0 (reference) | −0.0005 (−0.03, 0.03) | −0.01 (−0.05, 0.02) | −0.01 (−0.03, 0.04) | 0.002 (−0.03, 0.04) | 0.971 |
The coefficients and 95% CIs were estimated using a linear model, adjusting for age, BMI, ethnicity, education, family income, smoking status, drinking status, abstinence period, season, and temperature. Natural log transformation was applied for some sperm parameters
aALH amplitude of lateral head displacement, BCF beat cross frequency, CI confidence interval, LIN linearity, MAD mean angular displacement, PM2.5 particulate matter with aerodynamic less than 2.5 μm, STR straightness, VAP average path velocity, VCL curvilinear velocity, VSL straight line velocity, WOB curvilinear path wobble
bP trend value for adjusting FDR using the Benjamini & Hochberg procedure