Approved Research

Investigating a causal relationship between asthma and cardiovascular disease: a mendelian randomisation study

Lay summary

Asthma is a common long-term lung condition that affects children and adults. It has been shown in some studies that people with asthma also have a higher risk of having heart disease. There are many theories why these two conditions may occur together, for example both can be linked with inflammation in the body, or it may be one of the asthma drugs can cause a side-effect of increasing the risk of heart disease. However, the risk of heart disease in asthma has not be found in all studies, some have shown an increased risk while others have found no increase in a risk of heart disease. Because of these conflicting findings, another theory is that the studies themselves have limitations and may have falsely shown an increased risk. For example, some studies relied on people remembering events in the past and such memories can be influenced by a researcher asking people certain questions. Other studies may not have thought of other risk factors for heart disease properly, like smoking. Therefore, it remains unclear if asthma is linked to heart disease and importantly if asthma actually causes heart disease. This is important as asthma treatment may also affect a person's risk of heart disease.

To try to find out if asthma causes heart disease this project will use a special method that is increasingly used these days to find out if one thing causes another. This special method uses peoples' genes and tries to replicate the methods used in clinical trials which are known to be the best studies to use to show one thing (often a new drug) causes or prevents a disease. This study will use the data, including data on people's genes in the UK Biobank to answer this key question of wether asthma can cause heart disease and whether heart disease can cause asthma. This study will benefit individual patients who can be made aware of risk factors and receive appropriate health education. The study will benefit the NHS as a whole by reducing death rates, harm and the health costs of managing heart disease that could be prevented with timely personalised preventative interventions.