Relationships between lead biomarkers and diurnal salivary cortisol indices in pregnant women from Mexico City: a cross-sectional study

Table 3 Adjusted change in cortisol AM rise according to blood, tibia, and patella Pb concentrations in Mexico City women (2007–2011) ¹

Pb biomarker/quantile	% Change in cortisol per hour (95% CI)	β Coefficient (95% CI)
Blood Pb (n = 873) ²
Quintile 1 (0- < 1.8 µg/dL)	5 (−5, 16)	Ref
Quintile 2 (1.8- < 2.4 µg/dL)	5 (−5, 16)	0.00 (−0.06, 0.06)
Quintile 3 (2.4- < 3.4 µg/dL)	7 (−4, 18)	0.01 (−0.05, 0.07)
Quintile 4 (3.4- < 5.1 µg/dL)	−5 (−14, 5)	−0.04 (−0.11, 0.02)
Quintile 5 (≥5.1 µg/dL)	−8 (−16, 2)	−0.06 (−0.12, 0.00)
Continuous, per 2.5 µg/dL	N/A	−0.02 (−0.04, 0.00)
Tibia Pb (n = 575) ³
Quantile 1 (<2 µg/g)	4 (−4, 12)	Ref
Quantile 2 (2- < 4.3 µg/g)	−8 (−21, 7)	−0.05 (−0.12, 0.03)
Quantile 3 (4.3- < 6.7 µg/g)	7 (−7, 23)	0.02 (−0.05, 0.09)
Quantile 4 (6.7- < 11.1 µg/g)	−9 (−22, 5)	−0.05 (−0.12, 0.02)
Quantile 5 (≥11.1 µg/g)	8 (−7, 25)	0.02 (−0.05, 0.09)
Patella Pb (n = 568) ³
Quantile 1 (<2 µg/g)	2 (−6, 10)	Ref
Quantile 2 (2- < 4.5 µg/g)	11 (−3, 27)	0.04 (−0.03, 0.11)
Quantile 3 (4.5- < 7.8 µg/g)	−11 (−22, 3)	−0.05 (−0.12, 0.02)
Quantile 4 (7.8- < 12.7 µg/g)	−2 (−15, 12)	−0.01 (−0.08, 0.06)
Quantile 5 (>12.7-43.2 µg/g)	7 (−7, 23)	0.03 (−0.04, 0.10)

1-Only includes women who collected their first and second cortisol samples in the correct time window.
2-Salivary cortisol concentrations are modeled as a function of time since waking, Pb biomarker, a Pb biomarker x time interaction term, and covariates.
3-Adjusted for above covariates and maternal calf circumference at 1-month postpartum.

ISSN: 1476-069X