Associations between repeated measure of plasma perfluoroalkyl substances and cardiometabolic risk factors

Abstract

Background: Perfluoroalkyl substances (PFAS) are persistent synthetic chemicals that may affect components of metabolic risk through the peroxisome proliferator-activated receptor but epidemiological data remain scarce and inconsistent. Objective: To estimate associations between repeated measurements of the main PFAS in plasma and total cholesterol, triglycerides and hypertension among the control subjects from a population-based nested case-control study on diabetes type 2 in middle-aged women and men. Methods: Participants (n = 187) were free of diabetes at both baseline and follow-up visits to the Västerbotten Intervention Programme, 10 years apart: during 1990 to 2003 (baseline) and 2001 to 2013 (follow-up). Participants left blood samples, completed questionnaires on diet and lifestyle factors, and underwent medical examinations, including measurement of blood pressure. PFAS and lipids were later determined in stored plasma samples. Associations for the repeated measurements were assessed using generalized estimating equations. Results: Six PFAS exceeded the limit of quantitation. Repeated measures of PFAS in plasma, cardiometabolic risk factors and confounders, showed an average decrease of triglycerides from −0.16 mmol/l (95% confidence interval [CI]: −0.33, 0.02 for PFOA) to −0.26 mmol/l (95% CI: −0.50, −0.08 for PFOS), when comparing the highest tertile of PFAS plasma levels with the lowest. Associations based on average PFAS measurements and follow-up triglycerides revealed similar inverse associations, although attenuated. The estimates for cholesterol and hypertension were inconsistent and with few exception non-significant. Conclusions: This study found inverse associations between PFAS and triglycerides, but did not support any clear link with either cholesterol or hypertension. Keywords: Plasma perfluoroalkyl substances, Cardiometabolic risk factors, Lipids, Hypertension, Environmental epidemiology, Repeated measurements, Prospective assessment