Prenatal lead exposure and elevated blood pressure in children

• Published in: Environment international Vol. 121; no. Pt 2; pp. 1289 - 1296
• Main Authors: Farzan, Shohreh F., Howe, Caitlin G., Chen, Yu, Gilbert-Diamond, Diane, Cottingham, Kathryn L., Jackson, Brian P., Weinstein, Adam R., Karagas, Margaret R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.12.2018; Elsevier
• Subjects: Adult; Blood pressure; Child, Preschool; children's health; Environmental Exposure; Environmental Pollutants - adverse effects; Female; Humans; Hypertension - chemically induced; Hypertension - epidemiology; Lead; Lead - adverse effects; Male; New Hampshire; New Hampshire - epidemiology; Pregnancy; Pregnancy cohort; Prenatal Exposure Delayed Effects - chemically induced; Prenatal Exposure Delayed Effects - epidemiology; Prospective Studies; New Hampshire; Lead; Blood pressure; children's health; New Hampshire; Pregnancy cohort
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2018.10.049

Growing evidence suggests that environmental exposures can influence blood pressure over the course of a lifetime. Exposure to toxic metals, such as lead (Pb) and arsenic (As), has been associated with increased blood pressure in adults, but few studies have examined the impacts of in utero and early life toxic metals exposure on blood pressure in childhood. As subclinical vascular changes are thought to begin early in life, it is possible that in utero toxic metals exposure may play a role in blood pressure homeostasis. In the ongoing New Hampshire Birth Cohort Study, we investigated whether in utero exposure to Pb and As was associated with measures of blood pressure in a total of 323 young children (mean age 5.5 years, SD 0.4). Pb and As were measured in maternal toenail samples collected at ~28 weeks gestation (n = 257) and/or 6 weeks postpartum (n = 285), which represent exposures ~6 to 12 months prior to collection and therefore reflect the early prenatal and late prenatal exposures, respectively. Five measurements of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were averaged for each child using a standardized technique. In linear regression analyses, where log2-transformed prenatal toenail Pb and As were modeled jointly and adjusted for child age, sex, height, weight and maternal smoking during pregnancy, we observed that a doubling of maternal prenatal toenail Pb was associated with statistically significant increases in child SBP (β: 0.58 mm Hg, 95% CI: 0.05, 1.11). We did not observe any association of prenatal or postpartum As, or postpartum Pb, with SBP or DBP. Exploratory sex-stratified analyses suggest that associations of prenatal Pb with BP may be stronger among boys (SBP β: 0.72 mm Hg: 95% CI: −0.01, 1.44; DBP β: 0.37; 95% CI: −0.09, 0.84), compared to girls (SBP β: 0.48 mm Hg: 95% CI: −0.31, 1.26; DBP β: −0.05; 95% CI: −0.52, 0.41), though tests for interaction did not reach statistical significance (p-interaction SBP = 0.059; DBP = 0.057). Our preliminary results suggest that in utero toxic metals exposures may be associated with early life increases in blood pressure in children, which could have consequences for long-term health. •Few studies have examined the impacts of toxic metals exposure on child blood pressure.•In utero exposures were assessed using two measures of maternal toenail Pb and As.•In utero Pb exposure was associated with significant increases in child systolic BP.•Results suggest that influence of prenatal Pb on BP may be stronger among boys.•Prenatal Pb exposure may be associated with early life increases in BP in children.