The shorter a person is, the higher their risk of developing coronary heart disease (CHD), a new study has found.

According to the findings, for every 2.5 inch (6.5cm) change in height, the risk of CHD increases by 13.5%. As a result, a person who is five feet tall has a 32% higher risk of developing the disease than a person who is six inches taller.

"We have shown that the association between shorter height and higher risk of coronary heart disease is a primary relationship and is not due to confounding factors such as nutrition or poor socioeconomic conditions," commented Prof Sir Nilesh Samani of the University of Leicester.

CHD occurs when the body's blood supply to the heart is blocked or interrupted due to a build-up of fatty substances in the coronary arteries. It can lead to a range of problems, including angina, atherosclerosis (hardening of the arteries) and heart attack.

CHD is the most common cause of premature death worldwide. Every year in Ireland, around 10,000 people die from cardiovascular disease, which includes CHD.

According to the researchers, for more than 60 years, it has been known that there is an inverse relationship between height and the risk of CHD. However, it was not clear whether this was due to confounding factors such as poor nutrition during childhood.

"Now, using a genetic approach, researchers at the University of Leicester undertaking the study on behalf of an international consortium of scientists have shown that the association between shorter height and higher risk of coronary heart disease is a primary relationship and is not due to confounding factors," Prof Samani explained.

Genetic data on almost 200,000 people with and without CHD was assessed for the study. Some 180 genetic variants that affect height were also assessed to see if they were associated with CHD.

"The more height increasing genetic variants that you carry the lower your risk of coronary heart disease and conversely if you were genetically shorter the higher your risk," noted lecturer, Dr Christopher Nelson, who carried out the analysis.

The researchers pointed out that this is the first study to show that the known link between height and CHD risk ‘is at least in part due to genetics, rather than purely down to nutrition or lifestyle factors'.

"While we know about many lifestyle factors such as smoking that affect risk of CHD, our findings underscore the fact that the causes of this common disease are very complex and other things that we understand much more poorly have a significant impact.

"While our findings do not have any immediate clinical implications, better and fuller understanding of the biological mechanisms that underlie the relationship between shorter height and higher risk of CHD may open up new ways for its prevention and treatment," Prof Samani added.

Details of these findings are published in the New England Journal of Medicine.

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