Table 1.
Percent distribution of socio-demographic characteristics by provision of semen sample, LIFE Study (n=501)
| Characteristic | Provided semen sample (n=473) | Did not provide semen sample (n=28) | p-valuea |
|---|---|---|---|
|
|
|||
| n (%) | n (%) | ||
| Abstinence time (# days) | |||
| <2 | 2 (0.4) | NA | NA |
| 2 to 7 | 424 (89.6) | NA | |
| >7 | 34 (7.2) | NA | |
| Missing | 13 (2.8) | NA | |
| Mean (±SD) | 4.01 (4.5) | NA | |
| Age (years) | |||
| <25 | 16 (3.4) | 3 (10.7) | 0.18 |
| 25–29 | 151 (31.9) | 6 (21.4) | |
| 30–34 | 176 (37.2) | 10 (35.7) | |
| 35+ | 130 (27.5) | 9 (32.1) | |
| Mean (±SD) | 31.8 (4.9) | 31.7 (5.9) | |
| Alcohol consumption | |||
| Once a month or less | 65 (13.7) | 4 (16.7) | 0.55 |
| Two or three days a month | 75 (15.9) | 5 (17.9) | |
| Once a week | 105 (22.2) | 3 (10.7) | |
| Two or three times a week | 122 (25.8) | 7 (25.0) | |
| Four to six times a week or more | 37 (7.8) | 3 (10.7) | |
| Missing | 69 (14.6) | 4 (14.3) | |
| Body Mass Index | |||
| <18.5 (underweight) | 2 (0.4) | 0 (0.0) | 0.77 |
| 18.5–24.9 (normal weight) | 75 (15.9) | 3 (10.7) | |
| 25–29.9 (overweight) | 188 (39.8) | 14 (50.0) | |
| ≥30 (obese) | 184 (38.9) | 11 (39.3) | |
| Missing | 24 (5.1) | 0 (0.0) | |
| Mean (±SD) | 29.5 (5.0) | 29.2 (4.0) | |
| Education | |||
| High school grad/GEDc or less | 38 (8.0) | 6 (21.4) | 0.04 |
| Some college/technical school | 133 (28.1) | 9 (32.0) | |
| College graduate or higher | 298 (63.0) | 12 (42.9) | |
| Missing | 4 (0.9) | 1 (3.6) | |
| Household income | |||
| <$29,999 | 20 (4.2) | 6 (21.5) | <0.01 |
| $30,000 – $49,000 | 60 (12.7) | 3 (10.7) | |
| $50,000 – $69,999 | 66 (14.0) | 2 (7.1) | |
| $70,000+ | 44 (9.5) | 3 (10.7) | |
| Previously fathered (#) | |||
| 0 | 246 (52.0) | 13 (46.4) | 0.83 |
| 1 | 159 (33.6) | 10 (35.7) | |
| 2 | 50 (10.6) | 4 (14.3) | |
| 3 | 15 (3.2) | 0 (0.0) | |
| 4 | 1 (0.2) | 0 (0.0) | |
| missing | 2 (0.4) | 1 (3.6) | |
| Race/ethnicity | |||
| Hispanic | 38 (8.0) | 7 (25.0) | <0.01 |
| Non-Hispanic Black | 20 (4.2) | 3 (10.7) | |
| Non-Hispanic White | 381 (80.5) | 13 (46.4) | |
| Other | 34 (7.2) | 5 (17.9) | |
| Site | |||
| Michigan | 98 (20.7) | 0 (0.0) | <0.01 |
| Texas | 375 (79.3) | 28 (100.0) | |
| Geometric mean (95% confidence interval) | |||
| Urinary BPA (ng/mL) | 0.55 (0.48, 0.62) | 0.67 (0.36, 1.26) | 0.48 |
| Creatinine adjusted urinary BPA (μg/g) | 0.51 (0.46, 0.58) | 0.56 (0.31, 0.99) | 0.68 |
| Serum cotinine (ng/mL)d | 0.04 (0.04–0.06) | 0.09 (0.03–0.24) | 0.07 |
| Creatinine (mg/dL)d | 6.55 (6.45–6.66) | 6.66 (6.23–7.12) | 0.54 |
a
Chi-squared tests were used in the two-way comparisons of categorical variables between men who provided a semen sample and men who did not. Nonparametric Wilcoxon tests were used in the two-way comparisons of continuous variables between men who provided a semen sample and men who did not. P-values refer to differences in n (%) and geometric means (GM) and 95% Confidence Interval (CI)
b
NA= not applicable - no semen sample
c
GED= General Education Development Exam
d
Natural logarithm-transformed and standardized