Polish research confirms: air pollution is bad for your heart

The spotlight of the event, attended by approx. 30 thousand people - doctors, scientists, representatives of the pharmaceutical industry, patients and journalists, held from 29 August to 2 September was "Environment and the Heart."

The negative impact of environmental pollution on health was observed long ago. Dr. Jean-Francois Argacha from the University Hospital in Brussels reminded at a press conference that dramatic health consequences of air pollution were first described in Belgium in 1930 after the Meuse Valley fog. Due to the heavy air pollution and particular weather conditions, hundreds of people suffered from breathing disorders, and 60 people died because of this.

"Nowadays, the World Health Organization (WHO) considers air pollution as one of the largest avoidable causes of mortality. Besides the pulmonary and carcinogenic effects of air pollution, exposition to air pollution has been associated with an increased risk in cardiovascular mortality" - said the Belgian cardiologist.

This is confirmed by the results of two independent Polish research teams, which were presented at the congress of the European Society of Cardiology (ESC) in London.

A team of young researchers from the Jagiellonian University in Kraków under the supervision of Prof. Tomasz J. Guzik from Kraków and Prof. Andrzej Wysokiński from Lublin demonstrated that living in a polluted environment adversely affects the cardiovascular system in young healthy subjects. The study was conducted at the initiative of the Jagiellonian University medical students, and funded with a "Future Generation" grant of the Ministry of Science and Higher Education.

"We compared the risk indicators of cardiovascular disease in residents of two Polish cities - Kraków and Lublin, which are similar in terms of demographic and climatic conditions, but differ significantly in terms of air pollution. This applies especially to particulate pollutants with a diameter of 2.5 micrometers (PM2.5) and 10 micrometers (PM10)" - Prof. Guzik told PAP. He reminded that Kraków is in the top of the most polluted cities in Europe, while Lublin is located in the centre of one of the least polluted areas in Poland. According to the data the scientists obtained from air quality monitoring stations, in the last 10 years the concentration of PM2.5 and PM10 in Kraków was approx. two times higher than in Lublin.

A total of 826 young people aged 16-22 years were examined, of whom 444 lived in Kraków and 382 in Lublin. Blood pressure was measured in all cases, and blood samples were taken from 600 subjects to measure the concentrations of various compounds that are indicative of inflammation, for example CRP protein, fibrinogen, homocysteine. It is known that their elevated blood levels are factors in a higher risk of cardiovascular disease.

"Even though the subjects were young and completely healthy, people in which the risk of cardiovascular disease is not yet taken into account, in young men living in Kraków we found increased blood pressure compared with their peers from Lublin" - said Dr. Krzysztof Bryniarski, who presented the results at the congress. Moreover, in young people from Kraków there were clearly elevated levels of compounds indicative of the development of inflammation.

According to Dr. Bryniarski, this indicates that prolonged exposure to air pollution promotes the development of inflammation in the body, which in turn is a substrate of developing cardiovascular disease. "As a result, young people from Kraków may be much more likely at risk of a heart attack in the future than their peers from Lublin" - said the researcher.

Allergic diseases and rhinitis were also more common in young people from the capital of Małopolska.

They observed further that the effect of pollutants on the cardiovascular system is particularly adverse in patients with higher body mass index (BMI) - equal to or above 25 kg/m2, people struggling with overweight and obesity. "We observed that the increase in blood pressure and serum markers of inflammation was clearly - approximately four times - higher in those who lived in a more polluted city and were overweight or obese. In people with higher BMI living in Lublin, there were no such changes" - said Prof. Guzik. This means that there are interactions between the classic risk factors for cardiovascular disease and living in a polluted environment - obesity is more dangerous for the cardiovascular system, if you live in Kraków, he added.

A team of researchers from the 3rd Chair and Department of Cardiology, Medical University of Silesia, Silesian Center for Heart Diseases in Zabrze, observed in turn that air pollution can have a very negative impact on patients who in 2006-2012 were taken to hospital with acute coronary syndrome. The study included almost 2400 patients.

"The clinical condition of patients was evaluated by measuring the ejection fraction of the left ventricle, which indicates how efficiently the heart pumps blood, measuring bleeding risk with the CRUSADE scale, risk of future heart attack or death based on the GRACE scale, and on the basis of measurements of blood pressure and pulse" - told PAP Dr. Aneta Ciślak, one of the main authors, who presented the results of a study.

Data on air pollution were obtained from the research station of the Regional Inspectorate for Environmental Protection in Katowice, located near the Silesian Center for Heart Diseases in Zabrze.

"It turned out that on the days when higher levels of air pollutants: carbon monoxide, ozone and nitrogen oxides were recorded, the clinical condition of patients was the worst, and the results of invasive treatment of myocardial infarction were the least satisfying, both during the stay in hospital and within 30 days after surgery" - said Dr. Ciślak.

"A very important conclusion from this study is that air pollution in Silesia has a real impact on clinical condition of patients with heart disease" - told PAP study co-author Dr. Piotr Desperak.

Researchers explained that this may be connected with the fact that air pollution promotes inflammation in the body, and carbon monoxide irreversibly binds with haemoglobin and interferes with the transport of oxygen in the bloodstream. Associated hypoxia can also aggravate the patients’ condition.

Dr. Desperak noted that the team under the supervision of Prof. Mariusz Gąsior plans to carry out similar studies on larger groups of patients. Currently, researchers in consultation with the Silesian branch of the National Health Fund analyse the data of approx. 600 thousand patients hospitalised due to cardiovascular causes in the whole province of Silesia. The study aims to compare these data with measurements of pollution and weather conditions obtained from the stations nearest to the place of residence of patients.

Commenting on the findings presented by young scientists, Prof. Oscar Franco Duran from the Erasmus University Medical Center in Rotterdam said that the impact of pollution on the heart can be compared to the effects of cigarette smoking. However, in the case of pollution we do not get to choose what we breathe. For that reason, decisions of politicians on the implementation of regulations limiting pollution are very important, he added.

PAP - Science and Scholarship in Poland

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