PCBs (Polychlorinated biphenyls) are a group of environmental toxins that were banned almost 20 years ago. But since they accumulate through the food chain and remain for a very long time in the human body, high levels can still be found in a majority of the population of Sweden as well as in most other industrial countries.
High levels of PCBs have previously been found to be connected with risk factors for heart disease, such as obesity, diabetes and high blood pressure. The research group at Uppsala University has previously shown associations between environmental contaminants and atherosclerosis and stroke. Using the same large data set they have now shown that the PCBs are related to myocardial dysfunction.
The so-called PIVUS study (Prospective Investigation of Uppsala Seniors) comprises over 1,000 70-year-olds in Uppsala who have been studied over a longer period of time. The researchers measured 21 different environmental contaminants in plasma from the patients and used ultrasound to quantify heart function. The results show an association between high levels of several different PCBs and an impaired pumping ability of the heart (systolic dysfunction). Two other PCBs were connected with an impaired filling capacity of the heart (diastolic dysfunction).
The results are independent of factors such as sex, smoking, diabetes, high blood pressure and obesity. Those patients who have had heart attacks or atrial fibrillation were excluded from the study.
“Our conclusion is that there seems to be a connection between PCBs and myocardial function, which indicates that environmental contaminants can be significant to the development of heart problems”, says Lars Lind, Professor of Medicine at Uppsala University who has conducted the study together with Monica Lind, Associate professor in Environmental Medicine at the Department of Occupational and Environmental Medicine, and M.D. Ylva Sjöberg Lind at the University hospital in Linkoping, Sweden.
To understand the mechanisms behind this connection, more research is necessary in the form of laboratory studies.
The study is part of the so-called PIVUS study at Uppsala University.
The study has been funded by Formas and the Swedish Research Council.