Research led by the University of Granada and ibs.Granada–the biomedical research institute–affirms this is independent of factors like age, tobacco or alcohol use
The study involved over 300 patients in the southern Spanish province of Granada who donated blood and adipose tissue and participated in a 10-year follow-up
Research led by the University of Granada and ibs.Granada (Instituto de Investigación Biosanitaria), the biomedical research institute, has shown that in people with obesity, exposure to high levels of certain persistent organic pollutants (POPs) is associated with the risk of developing hypertension, independent of other factors like age, tobacco or alcohol use. What’s more, high levels of some of these pollutants doubles this risk.
These findings are drawn from a wide-ranging study called GraMo that, in 2003-04, involved more than 300 volunteers of both sexes who were going to undergo interventions in two hospitals in the province of Granada: San Cecilio University Hospital, Granada, and Santa Ana Hospital, Motril.
All participants donated samples of blood and adipose tissue. These were analysed for accumulated exposure to several pesticides and industrial compounds known as Persistent Organic Pollutants (POPs) because they are highly resistant to degradation. At 10 years after enrolment, the illnesses participants had had diagnosed during this time were recorded.
The results obtained demonstrated that the POPs associated with hypertension included hexaclorobenzene, formerly used as a fungicide and currently emitted in industrial processes; β-HCH, a compound related with the pesticide Lindane that was widely used in agriculture and in personal hygiene products; and three polychlorinated biphenyls (PCBs) used in different industrial applications, such as electric transformers, insulation or in heat exchange liquids.
Banned in Spain
«It’s important to stress that the use of all of these compounds is today banned in Spain. However, the entire study population presented residues of some of them in their organism since they are highly resistant to degradation», says University of Granada researcher Juan Pedro Arrebola, lead author of the study. Moreover, PCBs remain in obsolete industrial machinery and in some old buildings as well as in outdated pesticides stored in warehouses that often fail to meet safety standards, so they continue to be freed into the environment.
Currently, hypertension or high levels of arterial pressure affect 35% of the Spanish population. This is more frequent in people with obesity and is considered an important risk factor in cardiovascular and renal disease. In fact, hypertension is an important component of the so-called «Metabolic Syndrome», the term used to define the confluence of a group of cardiovascular risk factors including, as well as high blood pressure, others like obesity, diabetes or dyslipidemia.
Arrebola indicates that this study “contributes to an improvement in our knowledge about the possible relation between environmental pollution and the incidence of chronic conditions, especially those linked to the Metabolic Syndrome. The mechanisms of action in these compounds are not fully understood but they could include their interaction with certain hormone receptors (endocrine disruption) or the production of free radicals. It is believed that POPs could be involved in the syndrome and, in fact, in the GRaMo study we also found that exposure to POPs is associated with a high risk of diabetes, obesity and high cholesterol levels. These compounds tend to accumulate in body fat which could be one of the reasons why people with obesity are more prone to these pathologies».
Fatty foods
It is estimated that the principle 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 on diets rich in POPs, they are more prone to develop Metabolic Syndrome.
The University of Granada research group is currently continuing to work on the GraMo study to determine the possible effects of exposure to POPs and other pollutants in a range of pathologies as well as well as its mechanisms of action.
Researchers from a range of institutions-the University of Granada, Andalusian School of Public Health and University Hospital, Granada-integrated into ibs.Granada, have participated in this study. The results have recently appeared in Environmental Research.
References
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.
Photos of the University of Granada laboratory where the research team works and of some team members. From left to right: Inmaculada Jiménez, Chiara Pozzuoli, José Manuel Molina, Juan Pedro Arrebola and Francisco Artacho.
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Contact details:
Juan Pedro Arrebola
Instituto de Investigación Biosanitaria de Granada.
Hospital Universitario Virgen de las Nieves, Granada, Spain
Department of Radiology and Physical Medicine University of Granada
Phone: +34 958 240 758
Cellphone: +34 636 380 300
E-mail address: jparrebola@ugr.es
