Table 1.
Weighted characteristics of study population based on serum testosterone levels quartiles.
| Serum testosterone levels (ng/dL) | Q1 (≤300.0) | Q2 (>300, ≤398.8) | Q3 (>399.0, ≤521) | Q4 (>521.0) | P value |
|---|---|---|---|---|---|
| Age (years) | 40.8 ± 10.8 | 39.6 ± 11.5 | 38.2 ± 11.7 | 36.2 ± 11.9 | <0.001 |
| Race/ethnicity (%) | 0.2914 | ||||
| Non-Hispanic white | 62.6 | 60.5 | 63.2 | 60.0 | |
| Non-Hispanic black | 9.2 | 10.2 | 9.5 | 13.0 | |
| Mexican American | 11.6 | 12.6 | 11.2 | 11.1 | |
| Other race/ethnicity | 16.5 | 16.6 | 16.1 | 15.9 | |
| Education level (%) | 0.4021 | ||||
| Less than high school | 14.8 | 14.7 | 16.1 | 16.5 | |
| High school | 22.0 | 24.1 | 22.0 | 24.9 | |
| More than high school | 63.2 | 61.1 | 61.9 | 58.6 | |
| Body mass index (kg/m2) | 31.9 ± 6.7 | 29.2 ± 5.2 | 27.3 ± 4.6 | 25.7 ± 4.6 | <0.001 |
| Income-to-poverty ratio | 3.1 ± 1.6 | 3.0 ± 1.6 | 2.9 ± 1.6 | 2.7 ± 1.6 | <0.001 |
| Moderate activities (%) | 0.399 | ||||
| Both moderate recreational and work activities | 21.6 | 22.2 | 22.9 | 24.2 | |
| Moderate recreational activities | 23.6 | 22.9 | 24.8 | 24.2 | |
| Moderate work activities | 25.6 | 26.0 | 21.3 | 23.0 | |
| No moderate recreational or work activities | 29.2 | 28.9 | 30.9 | 28.6 | |
| Smoking status (%) | <0.001 | ||||
| Everyday | 12.4 | 17.0 | 18.2 | 22.5 | |
| Some day | 4.9 | 5.6 | 6.0 | 9.1 | |
| Past smoking | 27.0 | 20.8 | 21.7 | 19.1 | |
| Nonsmoker or smoked less than 100 cigarettes in life | 55.7 | 56.6 | 54.0 | 49.3 | |
| Had ≥12 alcohol drinks per year (%) | 0.026 | ||||
| Yes | 80.69 | 82.88 | 83.41 | 85.54 | |
| No | 15.51 | 12.24 | 12.60 | 10.10 | |
| Not recorded | 3.80 | 4.88 | 3.99 | 4.36 | |
| Blood urea nitrogen (mmol/L) | 4.82 ± 1.64 | 4.87 ± 1.48 | 4.80 ± 1.39 | 4.67 ± 1.48 | 0.029 |
| Serum uric acid (μmol/L) | 378.3 ± 78.2 | 364.8 ± 69.0 | 355.9 ± 63.7 | 335.7 ± 64.6 | <0.001 |
| Total protein (g/L) | 71.6 ± 4.5 | 71.7 ± 4.5 | 71.8 ± 4.3 | 72.3 ± 4.4 | 0.006 |
| Serum estradiol level (pg/mL) | 21.2 ± 8.4 | 22.4 ± 7.2 | 24.1 ± 7.3 | 29.7 ± 10.1 | <0.001 |
| Serum phosphorus (mmol/L) | 1.21 ± 0.18 | 1.21 ± 0.18 | 1.19 ± 0.18 | 1.19 ± 0.19 | 0.042 |
| Serum calcium (mmol/L) | 2.36 ± 0.09 | 2.36 ± 0.08 | 2.36 ± 0.08 | 2.37 ± 0.08 | <0.001 |
| Calcium supplement use 30 days (%) | 0.2892 | ||||
| ≤400 (mg) | 24.6 | 25.0 | 24.8 | 23.1 | |
| >400 (mg) | 12.1 | 10.3 | 10.0 | 9.0 | |
| Not recorded | 63.3 | 64.7 | 65.2 | 67.9 | |
| Appendicular fat mass index (kg/m2) | 4.4 ± 1.8 | 3.7 ± 1.2 | 3.3 ± 1.2 | 2.9 ± 1.1 | <0.001 |
| Appendicular lean mass index (kg/m2) | 9.4 ± 1.5 | 9.0 ± 1.3 | 8.7 ± 1.2 | 8.5 ± 1.3 | <0.001 |
| Lumbar bone mineral density (mg/cm2) | 1017.3 ± 154.6 | 1017.5 ± 153.4 | 1035.3 ± 149.3 | 1047.6 ± 149.5 | <0.001 |
Mean ± SD for continuous variables: P value was calculated by the weighted linear regression model. % for categorical variables: P value was calculated by the weighted chi-square test.