Table 1.
Socio-demographic and clinical characteristics of the 279 subjects enrolled from the NHANES 2003–2004 cycle according to normal vs. low total testosterone distribution (ng/dl)
| Variables | Total testosterone among NHANES participants | |||
|---|---|---|---|---|
| >350 ng/dl | <350 ng/dl | p value | ||
| Sample size, n (%) | 214 (76.7) | 65 (23.3) | – | |
| Total testosterone, ng/dl | Mean (SD) | 562.6 (168.3) | 247.4 (75.3) | 0.001 |
| Median (IQR) | 520 (426–649) | 268 (191–314) | ||
| Free testosterone, ng/dl | Mean (SD) | 25.1 (16.3) | 11.7 (7.1) | 0.004 |
| Median (IQR) | 18.3 (11.2–29.6) | 8.5 (5.5–14–3) | ||
| Bioavailable testosterone, ng/dl | Mean (SD) | 171.8 (109.4) | 82.8 (51.6) | 0.001 |
| Median (IQR) | 128 (67–246.5) | 64.7 (30.3–95.3) | ||
| Age, years | Mean (SD) | 44.1 (15.3) | 50.3 (16.7) | 0.045 |
| Median (IQR) | 44 (32–53) | 54 (35–63) | ||
| Age, group class, n (%) | 18–39 | 80 (37.4) | 13 (20) | 0.11 |
| 40–59 | 69 (32.2) | 19 (29.2) | ||
| 60+ | 65 (30.4) | 33 (50.8) | ||
| Mexican American | 43 (20.1) | 12 (18.5) | ||
| Race/ethnicity, n (%) | Non-Hispanic black | 42 (19.6) | 10 (15.4) | 0.37 |
| Non-Hispanic white | 129 (60.3) | 43 (66.2) | ||
| BMI | Mean (SD) | 27.1 (4.7) | 31.3 (5.9) | 0.006 |
| Median (IQR) | 26.5 (24.2–30.1) | 30.7 (28–35) | ||
| BMI group class, n (%) | 18.5–25 | 71 (33.2) | 8 (12.3) | 0.037 |
| 25–30 | 87 (40.7) | 20 (30.8) | ||
| >30 | 56 (26.2) | 37 (56.9) | ||
| Education group class, n (%) | <High school | 62 (29) | 19 (29.2) | 0.31 |
| High school | 57 (26.6) | 13 (20) | ||
| >High school | 95 (44.4) | 33 (50.8) | ||
| Smoking status, n (%) | Never smoker | 88 (41.1) | 34 (52.3) | 0.27 |
| Active smoker | 126 (58.9) | 31 (47.7) | ||
| Comorbidities | ||||
| Alcohol consumption, n (%) | ≤2 Drink/day | 99 (46.3) | 39 (60) | 0.08 |
| >2 Drink/day | 115 (53.7) | 26 (40) | ||
| Diabetes, n (%) | No | 195 (91.1) | 50 (76.9) | 0.41 |
| Yes | 19 (8.9) | 15 (23.1) | ||
| High cholesterol, n (%) | No | 193 (90.2) | 50 (76.9) | 0.16 |
| Yes | 21 (9.8) | 15 (23.1) | ||
| Hypertension, n (%) | No | 179 (83.6) | 47 (72.3) | 0.21 |
| Yes | 35 (16.4) | 18 (27.7) | ||
| Stroke, n (%) | No | 207 (96.7) | 60 (92.3) | 0.004 |
| Yes | 7 (3.3) | 5 (7.7) | ||
| Coronary artery disease, n (%) | No | 205 (95.8) | 61 (93.8) | 0.57 |
| Yes | 9 (4.2) | 4 (6.2) | ||
| Heart failure, n (%) | No | 209 (97.7) | 62 (95.4) | 0.61 |
| Yes | 5 (2.3) | 3 (4.6) | ||
| Cancer, n (%) | No | 195 (91.1) | 61 (93.8) | 0.03 |
| Yes | 19 (8.9) | 4 (6.2) | ||