Obese People Exposed to Certain Pollutants Have Twice the Risk of Developing Hypertension, Study Finds
An investigation led by the University of Granada (UGR) and the Instituto de Investigación Biosanitaria ibs.GRANADA has shown that there is a relationship between exposure to high levels of certain persistent organic pollutants (POPs) in obese people and their risk of developing hypertension regardless of other factors such as age and tobacco or alcohol consumption. What's more, having elevated levels of some of these pollutants doubles the risk of hypertension for obese people.
This finding is framed in a larger study called GraMo, in which more than 300 patients of both sexes voluntarily participated in 2003 and 2004 in two hospitals in the province of Granada: Hospital Universitario San Cecilio de Granada and Hospital Santa Ana de Motril.
All participants donated blood and fat samples, where accumulated exposure to various pesticides and industrial compounds was analyzed; known as Persistent Organic Pollutants (POPs), due to their great resistance to degradation. Ten years after recruitment, the diseases diagnosed in each participant during this period were recorded.
The results obtained showed that the POPs associated with hypertension included hexachlorobenzene, an ancient fungicide that is currently released in industrial processes; beta-HCH, a compound related to the pesticide lindane, which was widely used in agriculture and in personal hygiene products; and three polychlorinated biphenyls (PCBs), used in various industrial applications, such as in electrical transformers, insulators or in heat exchange liquids.
Banned in Spain
“It is important to highlight that the use of all the mentioned compounds is currently prohibited in Spain; However, the entire study population had residues of some of them in their body, since they are very resistant to degradation, explains the main author of the work, researcher Juan Pedro Arrebola. In addition, there are still PCBs in obsolete industrial equipment and in certain old buildings, in addition to obsolete pesticides stored in tanks that often do not meet safety standards, so they continue to be released into the environment.
Currently, hypertension or high blood pressure levels affect 35% of the Spanish population, it is more frequent in obese people, and it is considered an important risk factor for cardiovascular or kidney diseases. In fact, hypertension is an important component in the so-called “Metabolic Syndrome”, a term used to define the confluence of a set of risk factors for cardiovascular disease, which include, in addition to high blood pressure, others such as obesity , diabetes or dyslipidemia.
Arrebola points out that this study “contributes to the improvement of knowledge about the possible relationship between environmental pollution and the incidence of chronic diseases, especially those related to the Metabolic Syndrome. The mechanisms of action of these compounds are not fully understood, but could include their interaction with certain hormone receptors (endocrine disruption) or the production of free radicals. It is believed that POPs could be globally involved in the development of the syndrome, and in fact in the GRaMo study we have also found that exposure to POPs is associated with a high risk of diabetes, obesity and high cholesterol levels. In fact, the tendency of these compounds to accumulate in body fat could be one of the reasons why obese people are more prone to these pathologies ”.
Fatty foods
It is estimated that the main route of exposure to POPs in the general population is through the consumption of fatty foods. In fact, it has been shown that when experimental animals are fed diets rich in POPs, they are more likely to develop metabolic syndrome.
Currently, the UGR research group continues to work on the GraMo study to investigate the possible effects of exposure to POPs and other pollutants in various pathologies, as well as their mechanisms of action.
Researchers from various institutions have participated in this work, all of them integrated into the IBs.GRANADA Biosanitary Research Institute, which include the University of Granada, the Andalusian School of Public Health and the University Hospital Complex of Granada. The results have recently been published in the journal Environmental Research.
Bibliographic reference:
Historical exposure to persistent organic pollutants and risk of incident hypertension. Arrebola JP, Fernández MF, Martín-Olmedo P, Bonde JP, Martín-Rodríguez JL, Expósito J, Rubio-Domínguez A, Olea N. Environ Res. 2015 Apr; 138: 217-23. doi: 10.1016 / j.envres.2015.02.018.