Table 1.
Baseline characteristics of the study population in NHANES during the period 2007–2016.
| Variables | Non-asthma (n = 11,500) | Asthma (n = 2081) | p-value |
|---|---|---|---|
| Age (years), Median (Q1–Q3) | 36.0 (15–57) | 29.0 (14–52) | <0.001 |
| Gender (n), % | 0.056 | ||
| Man | 5,816 (50.6%) | 1,005 (48.3%) | |
| Woman | 5,684 (49.4%) | 1,076 (51.7%) | |
| BMI (Kg/m2), Mean ± SD | 26.1 ± 7.3 | 27.5 ± 8.6 | <0.001 |
| PIR (Ratio), Mean ± SD | 2.3 ± 1.6 | 2.2 ± 1.6 | <0.001 |
| Race (n), % | <0.001 | ||
| Mexican American | 2,210 (19.2%) | 247 (11.9%) | |
| Other Hispanic | 1,259 (10.9%) | 238 (11.4%) | |
| Non-Hispanic white | 4,186 (36.4%) | 830 (39.9%) | |
| Non-Hispanic Black | 2,485 (21.6%) | 539 (25.9%) | |
| Other Races | 1,360 (11.8%) | 227 (10.9%) | |
| Education (n), % | <0.001 | ||
| <9th Grade | 958 (8.3%) | 94 (4.5%) | |
| 9–11th Grade | 1,127 (9.8%) | 182 (8.7%) | |
| High School Grade | 1742 (15.1%) | 296 (14.2%) | |
| College | 2,173 (18.9%) | 443 (21.3%) | |
| ≥College Graduate | 1791 (15.6%) | 269 (12.9%) | |
| Do not know | 3,709 (32.3%) | 797 (38.3%) | |
| Marital status, N (%) | <0.001 | ||
| Married | 4,119 (35.8%) | 556 (26.7%) | |
| Widowed | 625 (5.4%) | 92 (4.4%) | |
| Divorced | 782 (6.8%) | 180 (8.6%) | |
| Separated | 248 (2.2%) | 43 (2.1%) | |
| Never married | 1,371 (11.9%) | 306 (14.7%) | |
| Living with partner | 648 (5.6%) | 107 (5.1%) | |
| Do not know | 3,707 (32.2%) | 797 (38.3%) | |
| Diabetes, N (%) | <0.001 | ||
| Yes | 960 (8.3%) | 230 (11.1%) | |
| No | 10,348 (90.0%) | 1812 (87.1%) | |
| Border line | 188 (1.6%) | 37 (1.8%) | |
| Do not know | 4 (0.0%) | 2 (0.1%) | |
| Hypertension, N (%) | <0.001 | ||
| Yes | 2,743 (23.9%) | 554 (26.6%) | |
| No | 5,861 (51.0%) | 903 (43.4%) | |
| Do not know | 2,896 (25.2%) | 624 (30.0%) | |
| Liver Disease, N (%) | <0.001 | ||
| Yes | 278 (2.4%) | 82 (3.9%) | |
| No | 7,502 (65.2%) | 1,199 (57.6%) | |
| Do not know | 3,720 (32.3%) | 800 (38.4%) | |
| Smoking, N (%) | <0.001 | ||
| Yes | 3,401 (29.6%) | 682 (32.8%) | |
| No | 4,554 (39.6%) | 636 (30.6%) | |
| Do not know | 3,545 (30.8%) | 763 (36.7%) | |
| Alcohol use, N (%) | <0.001 | ||
| Yes | 5,124 (44.6%) | 920 (44.2%) | |
| No | 2,138 (18.6%) | 324 (15.6%) | |
| Do not know | 4,238 (36.9%) | 837 (40.2%) | |
| Blood test, Mean ± SD | |||
| TP (g/dL) | 7.2 ± 0.5 | 7.1 ± 0.5 | <0.001 |
| Albumin (g/dL) | 4.3 ± 0.3 | 4.3 ± 0.3 | <0.001 |
| Globulin (g/dL) | 2.9 ± 0.5 | 2.9 ± 0.5 | 0.049 |
| ALT (U/L) | 24.6 ± 18.4 | 24.2 ± 15.9 | 0.47 |
| AST (U/L) | 25.7 ± 16.1 | 25.5 ± 12.9 | 0.603 |
| BUN (mg/dL) | 13.0 ± 5.5 | 12.5 ± 5.4 | <0.001 |
| Scr (mg/dL) | 0.9 ± 0.3 | 0.9 ± 0.3 | 0.361 |
| TB (mg/dL) | 0.7 ± 0.3 | 0.7 ± 0.3 | <0.001 |
| SUA (mg/dL) | 5.4 ± 1.4 | 5.4 ± 1.4 | 0.141 |
| GFR (mL/min/1.73 m2) | 98.3 ± 26.9 | 100.6 ± 27.3 | 0.002 |
| Urine metals, Mean ± SD | |||
| LnBa (μg/L) | 0.2 ± 1.0 | 0.2 ± 1.0 | 0.032 |
| LnCd (μg/L) | −1.9 ± 1.1 | −2.0 ± 1.1 | 0.008 |
| LnCo (μg/L) | −1.0 ± 0.8 | −0.9 ± 0.8 | <0.001 |
| LnCs (μg/L) | 1.4 ± 0.7 | 1.4 ± 0.7 | 0.852 |
| LnMo (μg/L) | 3.8 ± 0.9 | 3.8 ± 0.9 | 0.112 |
| LnPb (μg/L) | −0.9 ± 0.9 | −1.0 ± 0.9 | 0.002 |
| LnSb (μg/L) | −2.9 ± 0.8 | −2.8 ± 0.8 | 0.003 |
| LnTl (μg/L) | −1.9 ± 0.7 | −1.9 ± 0.7 | 0.039 |
| LnTu (μg/L) | −2.5 ± 1.1 | −2.4 ± 1.1 | <0.001 |
| LnHg (ng/mL) | −1.2 ± 1.1 | −1.3 ± 1.0 | 0.039 |
| LnU (ug/L) | −5.1 ± 1.0 | −5.0 ± 1.0 | <0.001 |
NHANES, National Health and Nutrition Examination Survey; SD, standard deviation; BMI, body mass index; PIR, poverty to income ratio; TP, total protein; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BUN, blood urea nitrogen; Scr, serum creatinine; TB, total bilirubin; SUA, serum uric acid; GFR, glomerular filtration rate; Ba, barium; Cd, cadmium; Co, cobalt; Cs, cesium; Mo, molybdenum; Pb, lead; Sb, stibium; Tl, thallium; Tu, tungsten; Hg, mercury; U, uranium.