Housatonic River Initiative

PCBs influence heart disease risk factors

Resource location: sciencedirect.com

Exposure to PCB 126, an organochlorine, produces high blood pressure and bigger hearts – factors that increase heart disease risk. Estrogen was not necessary for most effects of PCB 126, a dioxin- like, anti-estrogenic compound. Many factors - high blood pressure, high cholesterol, smoking, diabetes, and a large heart - raise the risk of heart disease, which is a major cause of death in industrialized countries. To find out if polychlorinated biphenyls (PCBs) influence heart disease risk factors and if estrogen plays a role, researchers exposed young female rats with and without ovaries to five injections totaling 224 micrograms of PCB 126. Obesity, blood glucose, blood lipids (cholesterol, HDL, triglycerides), blood pressure, and heart weight were evaluated. No difference in weight and blood sugar were found but exposure increased lipids, blood pressure, and heart size. Blood HDL cholesterol levels were higher in the animals without ovaries than those with intact, estrogen-producing ovaries. PCB exposure increased HDL levels in both groups while it lowered blood triglyceride levels in both groups. Blood pressure increased after exposure in animals with ovaries and estrogen. PCB 126 alters several known risk factors that may contribute to heart disease, including two - blood pressure and large heart size - that were linked for the first time. These results align with experimental studies that found organochlorines interfere with lipid metabolism to alter fat ratios and increase heart disease risk and epidemiology studies linking dioxin exposure to increased heart disease mortality.

Lind, PM, and J Orberg, U-B Edlund, L Sjoblom, and L. Lind. 2004. The Dioxin-like Pollutant PCB 126 (3,3',4,4',5- pentaclorobiphenyl) affects Risk Factors for Cardiovascular Disease in Female Rats. Toxicology Letters. Online April 04.