Tye E. Arbuckle’s research while affiliated with ASL Environmental Sciences and other places

Context During pregnancy, women who experience certain pregnancy complications show elevations in biomarkers of inflammation and insulin resistance; however, few studies have examined these cardiometabolic biomarkers in the decade following pregnancy. Objective To examine the association between pregnancy complications and cardiometabolic biomarkers 9 years postpartum including: blood pressure, blood lipids, body fat percentage, insulin resistance (glucose, insulin, proinsulin, C-peptide, HOMA-IR, HbA1c, leptin, adiponectin) and inflammation (hs-C-reactive protein). Methods Using data from the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort study (2008-2021) we determined 3 groups of pregnancy complications: 1) hypertensive disorders of pregnancy (HDP) (n=35); any pregnancy complication in the index pregnancy, defined as preterm birth, HDP, impaired glucose tolerance or gestational diabetes mellitus (GDM) (n=55); or self-reported recurrence of one of these pregnancy complications (n=19). Our comparison group included 186 women with uncomplicated pregnancies. Results In our adjusted linear regression results, all pregnancy complication groups showed significantly higher systolic and diastolic blood pressure 9 years later. HOMA-IR was 23% (95% CI: -4.4%, 57%), 26% (95% CI: 2.0%, 55%), and 51% (95% CI: 12%, 104%) higher at follow-up in participants who had experienced a prior HDP, an index pregnancy complication, or a recurrent pregnancy complication respectively. Elevations were also seen with HbA1c, insulin, C-peptide, and leptin especially among those with recurrent complications. Conclusion This study contributes to the body of evidence that women with a history of certain pregnancy complications merit special attention in the prevention of CVD. We recommend further exploration into these associations in larger cohorts.

Background: Folic acid (FA) supplementation may attenuate the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but to our knowledge, this has not been assessed for lead. Objectives: We examined whether the relationship between gestational blood-lead levels (BLLs) and autistic-like behaviors was modified by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype. Methods: We used data from the Maternal-Infant Research on Environmental Chemicals study (2008-2011), a Canadian pregnancy and birth cohort study. Childhood autistic-like behaviors were documented in 601 children 3-4 y of age with the Social Responsiveness Scale-2 (SRS-2), where higher scores denote more autistic-like behaviors. We measured BLLs and plasma total folate concentrations during the first and third trimesters of pregnancy. We also estimated gestational FA supplementation via surveys and genotyped the maternal MTHFR 677C>T single nucleotide polymorphism (SNP). We estimated the confounder-adjusted associations between log2-transformed BLLs and SRS-2 scores by two indicators of folate exposure and maternal MTHFR 677C>T genotype using linear regression. Results: Third-trimester BLLs were associated with increased SRS-2 scores [βadj=3.3; 95% confidence interval (CI): 1.1, 5.5] among participants with low (<10th percentile), third-trimester, plasma total folate concentrations, but BLL-SRS-2 associations were null (βadj=-0.3; 95% CI: -1.2, 0.5) among those in the middle category (≥10th and <80th percentiles) (p-interaction <0.001). FA supplementation also attenuated these associations. Both folate indicators modified first-trimester BLL-SRS-2 associations, but to a lesser extent. Third-trimester BLL-SRS-2 associations were slightly stronger among participants who were homozygous for the T (minor) allele of the MTHFR 677C>T SNP (βadj=0.9; 95% CI: -1.2, 3.1) than those without the T allele (βadj=-0.3; 95% CI: -1.3, 0.7), but the difference was not statistically significant (p-interaction=0.28). Discussion: Folate may modify the associations between gestational lead exposure and childhood autistic-like behaviors, suggesting that it mitigates the neurotoxic effects of prenatal lead exposure. https://doi.org/10.1289/EHP14479.

Background Few high-quality studies have evaluated associations between urinary glyphosate or its environmental degradate (aminomethylphosphonic acid (AMPA)] and preterm birth (PTB). Objectives To quantify associations between urinary glyphosate and AMPA and preterm birth in the pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study and determine if associations differ by fetal sex. Methods We measured first trimester urinary glyphosate and AMPA concentrations in MIREC participants who were recruited between 2008–2011 from 10 Canadian cities. Of the 1880 participants whose first trimester urine samples were analyzed for glyphosate or AMPA, 1765 delivered a singleton, live birth. Our primary outcome was preterm birth (PTB) defined as births occurring between 20 and <37 weeks. Secondary outcomes were spontaneous preterm births (sPTB) and gestational age. We modelled the hazard of PTB and sPTB using discrete time survival analysis with multivariable logistic regression to calculate odds ratios (OR). We used multivariable linear regression models to quantify associations between analytes and gestational age. To assess effect modification by fetal sex, we stratified all models and calculated interaction terms. In the logistic regressions models we additionally calculated the relative excess risk due to interaction. Results Six percent (n = 106) of the study population delivered preterm, and 4.7% (n = 83) had a spontaneous preterm birth. Median specific-gravity standardized concentrations of glyphosate and AMPA were 0.25 and 0.21 µg/L. Associations between both glyphosate or AMPA and PTB, sPTB, and gestational age centered around the null value. The adjusted ORs of PTB for each doubling of glyphosate and AMPA concentrations were 0.98 (95% CI: 0.94, 1.03) and 0.99 (95% CI: 0.92, 1.06) respectively. We observed no evidence of differences by fetal sex. Conclusions In this Canadian pregnancy cohort, neither glyphosate nor AMPA urinary concentrations was associated with PTB or reduced gestational length.