Childhood exposure to polycyclic aromatic hydrocarbons (PAHs) and cardiometabolic indicators in childhood and adolescence: findings from a cohort study in rural Bangladesh

Background

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with cardiovascular diseases in adulthood, but studies examining childhood origins are scarce.

Objective

To examine associations of childhood PAH exposure with cardiometabolic risk indicators in childhood and adolescence along with differences by sex.

Methods

Urinary PAH metabolites [Σ1,2,3-hydroxyphenanthrene (Σ1,2,3-OH Phe), 1-hydroxypyrene (1-OH Pyr), and Σ2,3-hydroxyfluorene (Σ2,3-OH Flu)] were measured in 9-year-olds from the MINIMat cohort in Bangladesh (n = 196), using liquid chromatography with tandem mass spectrometry. Cardiometabolic indicators [lipids, C-reactive protein (CRP), insulin resistance (HOMA2 IR), blood pressure, anthropometry, and a composite cardiometabolic risk score (CMRS)] were assessed at 9 and 15 years. Associations of PAH metabolites (log₂-transformed) with cardiometabolic indicators were assessed using multivariable-adjusted linear and logistic regression models.

Results

In all children, urinary 1-OH Pyr (median: 1.6 ng/mL) was positively associated with body mass index z-score at 9 and 15 years, and with triglyceride/high-density lipoprotein (HDL), cholesterol/HDL ratios, waist circumference, CMRS, and CRP at 15 years. After sex stratification, consistent associations were mainly observed in girls, especially with outcomes at age 15, where both urinary 1-OH Pyr and Σ1,2,3-OH Phe concentrations were inversely associated with HDL, and positively associated with the cholesterol/HDL ratio and CMRS. Urinary 1-OH Pyr was also positively associated with girls’ triglyceride/HDL ratio, HOMA2 IR, waist circumference, and CRP.

Conclusions

Our associations of childhood PAH exposure with cardiometabolic indicators in childhood and adolescence differed by sex. In girls, increased adiposity, indications of altered lipid profile and metabolic function were detected while boys seemed incongruently affected.