Table 3. Percent differences (95% CI) in the serum TT by quartiles of blood lead exposure, NHANES, 2011–2012using weighted regression models.
| Blood lead(μg/dL) | Model 1a | Model2b |
|---|---|---|
| Male children(N = 431) | ||
| ≤0.52(n = 110) | Reference | Reference |
| 0.52–0.72(n = 111) | 4.1 (-18.47, 32.9) | 11.75(-13.06,43.65) |
| 0.72–1.02 (n = 105) | -6.13(-27.64, 21.77) | -4.63(-26.97, 24.55) |
| >1.02 (n = 105) | -12.83 (-33.68, 14.58) | -13.09 (-34.45,15.22) |
| Adjusted p-trend | 0.36 | 0.42 |
| Male adolescents(N = 493) | ||
| ≤0.47(n = 129) | Reference | Reference |
| 0.47–0.66 (n = 120) | -3.36 (-20.98,18.2) | -4.35 (-21.22,16.14) |
| 0.66–0.96 (n = 121) | 14.99 (-7.77,43.37) | 8.15 (-12.91,34.3) |
| >0.96 (n = 123) | 15.62 (-7.07,43.86) | 6.32 (-14.62,32.4) |
| Adjusted p-trend | 0.18 | 0.58 |
| Female children(N = 426) | ||
| ≤0.48(n = 109) | Reference | Reference |
| 0.48–0.65 (n = 106) | 14.34 (-3.75,35.81) | 14.9 (-3.54,36.86) |
| 0.65–0.93 (n = 106) | -5.00 (-21.05,14.32) | -0.96 (-17.80,19.34) |
| >0.93 (n = 105) | -5.73 (-23.13,15.61) | -2.40 (-21.00,20.57) |
| Adjusted p-trend | 0.36 | 0.63 |
| Female adolescents(N = 470) | ||
| ≤0.35 (n = 122) | Reference | Reference |
| 0.35–0.47 (n = 118) | -8.55 (-18.52,2.63) | -7.83 (-18.22,3.88) |
| 0.47–0.63 (n = 113) | -1.95 (-13.04,10.56) | -1.07 (-12.67,12.06) |
| >0.63 (n = 117) | 13.12 (0.06,27.88) | 14.85 (0.83,30.81) |
| Adjusted p-trendc | 0.14 | 0.08 |
aAdjusted for age (continuous), BMI (normal/underweight, overweight, and obese) and race-ethnicity (Non-Hispanic White, Non-Hispanic black, Hispanic, and other).
b Adjusted for variables in model 1 plus serum cotinine (log-transformed, continuous), time of venipuncture (morning, afternoon, and evening), season of collection (1 November through 30 April, 1 May through 31 October), ratio family income to poverty (continuous).
c Adjusted p-trend:p-values adjusted for multiple testing.