Cardiovascular Disease

What is cardiovascular disease?

The cardiovascular (CV) system is comprised of the heart and the bodies vascular system (our blood vessels). Hence, cardiovascular disease (CVD) is a term used to describe a range of diseases involving the heart or blood vessels.

One of the most prolific ways of developing a CVD is atherosclerosis. Atherosclerosis is the development of fatty plaque deposits building up in blood vessels, these deposits limit blood flow and can lead to blood clots^[3]. In this way atherosclerosis can lead to a person developing a range of CVD’s including, a stoke and coronary heart disease. The type of CVD which develops depends on where in the body these plaques form. In the image below we can see one of these plaques in a coronary artery (an artery which supplies blood to heart muscle) limiting blood flow in this area and as a result causing coronary heart disease.

Image Credit: https://www.physio-pedia.com/Atherosclerosis^[2]

There are many more types of CVD’s than described above. For an extended list, follow this link.

So, why is all of this linked to global warming?

As global warming continues the occurrence of extreme heatwaves is extremely likely to increase, with this our bodies will (in many areas of the world) experience more and more thermal stress. Luckily, we have evolved to have adaptive mechanisms to counteract heat stress, these include sweating and blood vessel dilation. As well as this each cell within our body is able to regulate the synthesis of heat shock proteins (HSP), a family of protenis which can halt protein degradation following heat stress^[1].

However, these protective mechanisms can only counteract the effects of thermal stress up until a certain point. Under extreme thermal stress even extremely healthy individuals will experience alterations and changes in the functioning of their heart and the overall health of their blood vessels. Below is a concise image from a review published in 2020 outlining the effects of extreme thermal stress on the CV system.

With all of this in mind it is apparent that if global warming continues our bodies CV system will experience an intense negative impact. This is worrying now more than ever as news articles like this, published by the BBC are exposing the trend we are seeing with heatwaves. It explains how globally since 1980 the number of days where a temperature above 50°C is recorded has doubled^[4]. Our bodies cannot cope with this type of extreme environment and so we need to reverse this trend rapidly.

References

[1] Gostimirovic M, Novakovic R, Rajkovic J, Djokic V, Terzic D, Putnik S, Gojkovic-Bukarica L. The influence of climate change on human cardiovascular function. Archives of environmental & occupational health. 2020 Oct 2;75(7):406-14.

[2] Hampton L. Atherosclerosis [Internet]. 2021 [cited 14 September 2021]. Available from: https://www.physio-pedia.com/Atherosclerosis

[3] Pahwa R, Jialal I. Atherosclerosis. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507799/

[4] Dale B, Stylianou N. Climate change: World now sees twice as many days over 50C [Internet]. 2021 [cited 14 September 2021]. Available from: https://www.bbc.co.uk/news/science-environment-58494641