Abstract Body: Background: Heavy metals are cardiovascular disease risk factors, while essential elements possess antioxidant and anti-inflammatory properties and are crucial for health at trace levels. Metals may also interact with elements, leading to synergistic or antagonistic health effects. The associations of a mixture of metals and elements during pregnancy with women’s mid-life blood pressure (BP) and hypertension are unclear.
Objective: To examine the prospective associations of a mixture of 6 metals, 5 elements, and 2 micronutrients in early pregnancy with women’s BP and risk of hypertension in mid-life.
Methods: Project Viva is a prospective pregnancy cohort that enrolled women between 1999-2002 from Eastern MA. We measured metals (As, Ba, Cd, Cs, Hg, Pb) and elements (Cu, Mg, Mn, Se, Zn) in red blood cells, along with folate and vitamin B12 in plasma, all collected during pregnancy (median: 9.9w gestation). We measured mid-life BP in 2017-2020 (median maternal age: 51.2y). We examined associations of individual metals and elements with BP using linear regression and with hypertension (BP ≥130/80 mmHg or use of anti-hypertensive medication) using modified Poisson regression. We used Bayesian kernel machine regression (BKMR) to examine the mixture effects of all exposures. Models were adjusted for confounders listed in the Figure footnote.
Results: Of the 493 women, 72% were White, 78% were college graduates, and 65% had a household income >$70K/y. The median (IQR) follow-up time was 18.1 (17.8-18.6)y. A doubling of Cu and Mn concentrations was associated with 0.75 (95% CI: 0.57, 0.99) and 0.80 (95% CI: 0.71, 0.91) times the risk of hypertension, respectively. A doubling of Cs and Se was respectively associated with 1.22 (95% CI: 0.94, 1.57) and 1.19 (95% CI: 0.77, 1.83) times the risk of hypertension, though the 95% CIs were wide. A doubling of vitamin B12 was associated with a 3.64 (95% CI: 1.23, 6.04) mmHg lower systolic BP and a 2.52 (95% CI: 0.72, 4.32) mmHg lower diastolic BP (Figure 1). BKMR showed similar, linear associations for BP (results not shown) and hypertension (Figure 2) and did not identify metal-element or metal-micronutrient interactions. The essential element mixture was monotonically associated with lower BP and risk of hypertension (Figure 3).
Conclusion: Optimizing essential element levels during pregnancy, particularly Cu and Mn, along with vitamin B12, may offer protective benefits against higher BP and hypertension in mid-life women.