Table 2.
Odds Ratios (ORs) and 95% Wald Confidence Intervals (CIs) for the association between elevated joint neurodevelopmental toxicant exposure a and race/ethnicity among nonpregnant, reproductive-aged (15−44 years) women from NHANES 2003−2004.
| OR (95% CI) | |||||
|---|---|---|---|---|---|
| Univariate | Multivariate | Multivariate by Allostatic Load b | |||
| Low | Intermediate | High | |||
| n = 1,181 | n = 316 | n = 609 | n = 203 | ||
| Race/Ethnicity | n = 1,250 | ||||
| Caucasian | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| African American | 1.7 (1.0, 2.6) | 2.2 (1.4, 3.3) | 1.2 (0.5, 2.7) | 2.7 (1.6, 4.5) | 4.3 (2.0, 9.5) |
| Mexican American | 2.0 (1.3, 3.0) | 1.4 (0.7, 2.6) | 0.8 (0.2, 4.1) | 1.9 (0.9, 4.0) | 4.2 (1.3, 14.1) |
| Country of Birth | n = 1,250 | ||||
| United States | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Foreign | 3.1 (1.8, 5.4) | 3.3 (1.6, 6.8) | 10.3 (2.5, 43.2) | 2.2 (1.2, 4.3) | 1.8 (0.4, 8.1) |
| Age (years) | n = 1,250 | ||||
| 15−19 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| 20−28 | 2.1 (1.4, 3.2) | 1.8 (1.0, 3.2) | 2.5 (0.9, 7.4) | 1.6 (0.6, 4.2) | 19.1 (1.8, 201.6) |
| 29−44 | 4.1 (3.1, 5.5) | 3.5 (2.4, 5.1) | 6.3 (2.2, 17.7) | 3.9 (1.8, 8.4) | 33.3 (3.6, 305.5) |
| Highest Education c | n= 1,250 | ||||
| Less than high school graduate | 1.4 (0.8, 2.5) | 0.8 (0.5, 1.5) | 1.9 (0.5, 7.6) | 0.7 (0.3, 1.7) | 0.6 (0.1, 2.9) |
| High school graduate | 0.6 (0.3, 1.0) | 0.4 (0.2, 0.6) | 0.6 (0.2, 1.8) | 0.4 (0.2, 0.6) | 0.5 (0.1, 4.3) |
| Some college | 0.5 (0.3, 0.8) | 0.8 (0.5, 1.5) | 0.8 (0.4, 1.7) | 0.2 (0.1, 0.4) | 0.7 (0.2, 2.8) |
| College graduate or above | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Smoking Status (serum cotinine) | n = 1,225 | ||||
| Nonsmoker (≤10 ng/mL) | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Smoker (>10 ng/mL) | 2.0 (1.4, 3.0) | 3.0 (1.7, 5.0) | 2.0 (0.8, 4.6) | 3.8 (2.0, 7.4) | 3.4 (1.1, 10.6) |
| Iron Status Indicatord | n = 1,250 | ||||
| Normal | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Abnormal | 0.7 (0.5, 1.0) | 0.6 (0.5, 0.8) | 1.1 (0.5, 2.4) | 0.5 (0.3, 0.7) | 0.7 (0.3, 1.4) |
Notes: a Elevated NDT exposure was defined as having a hazard index (HI) for joint lead (Pb) and methyl mercury (MeHg) greater than one (HINDT > 1). The HI was calculated by summing individual hazard quotients (HQs) for Pb and MeHg (Equation 1). HQs were calculated by dividing blood concentrations of Pb and MeHg by 1.76 µg/dL and 5.8 µg/L, respectively. b Allostatic load (AL), a measure of physiological dysregulation, was used as an indicator of chronic stress exposure and was estimated based on the categorical classification of AL-clinical scores (0 = Low; 1−2 = Intermediate; >2 = High) and calculated by summing the number of 10 biomarkers above clinical high risk criteria (Equation 2). c If the participant was <18 years of age, status of the head of household was used. dIron status was determined to be abnormal if any two of the following conditions were met: (1) serum ferritin <15 ng/mL, (2) transferrin saturation <16%, (3) red blood cell distribution width >15%, or (4) erythrocyte protoporphyrin >50 µg/dL red blood cells.