Environmental Contaminant Body Burdens and the Relationship with Blood Pressure Measures Among Indigenous Adults.

Abstract

Using data from the Environment-and-Health Study, the sample was restricted to adults with valid BP measures and detectable body burden mixtures. In total, n = 759 participants were eligible, of which, n = 447(59%) were females. Principal Component Analysis (PCA) was used to reduce the complexity of the contaminant data. Orthogonal principal component (PC) variables, and sum (∑) of contaminant compounds were used as independent predictors in modified Poisson regression models with robust variance estimation, deriving prevalence ratios (PR) for hypertension, that is, systolic BP (SBP) ≥140 ml of mercury (mmHg), or diastolic BP ≥90 mm Hg. Additionally, using multivariable generalized linear regression, sex-stratified continuous SBP measure was regressed on ∑ contaminant compounds. Two PCs were extracted from the PCA analysis. PCBs and OCs positively highly loaded on the first axis (PC-1). Lead loaded positively on the second (PC-2) axis. Hypertension was consistently associated with PC-1 across models, PR = 1.08 (95% confidence intervals = 1.003 to 1.172) fully adjusted model. Examining ∑ of contaminants, the strength of association with hypertension was strongest for ∑OCs compared with ∑PCBs. The measure of effect for continuous SBP measures with ∑ dichlorodiphenyltrichloroethane(p,p'-DDT) and dichlorodiphenyldichloroethylene(p,p'-DDE) concentrations although small was similar for both females and males, β = 0.04 (95% confidence intervals = 0.005 to 0.075) among females; however, for males the estimate is imprecise after adjusting for body mass index. This cross-sectional analysis found that PCBs and OCs were associated with associated prevalent hypertension; and exposure to OC pesticides, particularity DDT/DDE were found to be associated with prevalent SBP measures among females and not males.