Table 1.
Participant characteristics according to antinuclear antibody (ANA) positivity among females 16–49 years of age in the general U.S. population (NHANES).
| Characteristic | NHANES 1999–2000 | NHANES 1999–2004 | ||||
|---|---|---|---|---|---|---|
| ANA positivea(n = 56) | ANA negativea(n = 396) | p‑Value | ANA positivea(n = 213) | ANA negativea(n = 1,139) | p‑Value | |
| Age (years) | 31.7 ± 2.8 | 32.7 ± 0.7 | 0.71 | 33.7 ± 0.02 | 33.6 ± 0.06 | 0.14 |
| Race/ethnicity | 0.08 | 0.25 | ||||
| White, non-Hispanic | 15 (74.2) | 135 (64.1) | 85 (71.5) | 458 (64.4) | ||
| Black, non-Hispanic | 12 (10.7) | 73 (10.7) | 48 (12.9) | 256 (12.9) | ||
| Mexican American | 26 (12.3) | 136 (7.3) | 63 (8.7) | 306 (9.0) | ||
| Other Hispanic | 2 (2.6) | 32 (9.9) | 13 (5.1) | 65 (6.5) | ||
| Others | 1 (0.2) | 20 (8.1) | 4 (1.8) | 54 (7.1) | ||
| Education | 0.28 | 0.04 | ||||
| < High school | 9 (18.1) | 74 (14.8) | 48 (17.2) | 227 (14.7) | ||
| High school graduate/GED | 15 (34.3) | 61 (20.2) | 38 (21.9) | 198 (22.1) | ||
| Some college/graduate school | 16 (43.3) | 134 (52.7) | 88 (55.8) | 446 (55.1) | ||
| Youth (16–19 years) | 16 (4.3) | 127 (12.3) | 39 (5.1) | 268 (8.2) | ||
| BMI (kg/m2) | 26.6 ± 1.1 | 27.3 ± 0.5 | 0.57 | 26.6 ± 0.1 | 27.5 ± 0.2 | 0.11 |
| Smokingb | 0.77 | 0.32 | ||||
| Never | 27 (60.7) | 171 (57.1) | 111 (61.2) | 529 (55.6) | ||
| Former | 7 (17.4) | 40 (15.0) | 28 (15.1) | 130 (15.3) | ||
| Current | 5 (21.9) | 58 (28.0) | 34 (23.8) | 212 (29.2) | ||
| Serum cotinine (ng/mL)c | 0.68 ± 0.43 | 0.75 ± 0.25 | 0.87 | 0.32 ± 0.11 | 0.62 ± 0.11 | 0.07 |
| C-reactive protein (mg/dL)c | 0.13 ± 0.03 | 0.18 ± 0.02 | 0.30 | 0.14 ± 0.00 | 0.18 ± 0.02 | 0.25 |
| < 1 mg/dL | 51 (84.5) | 336 (89.3) | 0.54 | 193 (92.1) | 978 (87.4) | 0.57 |
| ≥ 1 mg/dL | 5 (15.6) | 60 (10.7) | 20 (7.9) | 161 (12.6) | ||
| Selenium, dietary (μg)c | 87.9 ± 9.2 | 78.7 ± 4.0 | 0.30 | 85.5 ± 2.3 | 82.8 ± 1.6 | 0.52 |
| Omega-3, dietary (g)c | 0.02 ± 0.01 | 0.03 ± 0.003 | 0.57 | 0.02 ± 0.003 | 0.02 ± 0.001 | 0.57 |
| Hair Hg (ppm)c | 0.27 ± 0.04 | 0.21 ± 0.03 | 0.03 | NA | NA | NA |
| Total blood Hg (μg/L)c | 1.31 ± 0.17 | 1.01 ± 0.12 | 0.06 | 0.97 ± 0.00 | 0.91 ± 0.05 | 0.43 |
| Urinary Hg (μg/L)c | 0.80 ± 0.16 | 0.65 ± 0.08 | 0.34 | 0.67 ± 0.03d | 0.62 ± 0.05d | 0.56 |
| ANA titer | NA | NA | ||||
| Negative (≤ 1:40) | NA | 396 (100) | NA | 1,139 (100) | ||
| 1:80 | 0 | NA | 0 | NA | ||
| 1:160 | 2 (1.2) | NA | 3 (0.4) | NA | ||
| 1:320 | 16 (21.3) | NA | 42 (17.6) | NA | ||
| 1:640 | 14 (18.1) | NA | 64 (32.8) | NA | ||
| ≥ 1:1,280 | 24 (59.5) | NA | 104 (49.2) | NA | ||
| ANA patterne | NA | NA | ||||
| Nuclear (all) | 52 (98.9) | NA | 208 (99.7) | NA | ||
| Speckled | 50 (94.4) | NA | 203 (96.3) | NA | ||
| Nucleolar | 4 (3.1) | NA | 14 (5.1) | NA | ||
| Homogeneous | 1 (4.4) | NA | 3 (2.3) | NA | ||
| Abbreviations: Hg, mercury; NA, not applicable. aValues are mean ± SD or n (%); means and percentages are weighted. bSmoking data were available for ages ≥ 20 years (n = 308 for first cycle; n = 1,044 for 3 cycles). cGeometric mean ± geometric SD. dData for NHANES 1999–2002 (n = 804; data were unavailable for 2003–2004). eThree major types of nuclear staining patterns were tabulated, and more than one ANA pattern is possible; 3.1% (cycle 1) and 5.1% (cycles 1–3) of participants had more than one pattern. | ||||||