Research reveals links between birthweight and heart disease risk

May 06, 2024

28 August 2023 Rachel Tyler

Category: Research

New research, part-funded by us, and presented at the European Society of Cardiology Congress 2023, has revealed that having a low birthweight increases the risk of developing heart disease, independently of the intrauterine environment. The findings suggest that – when considered alongside traditional risk factors – birthweight could help build a better picture of individuals’ risk of heart disease, helping identify those who could benefit from more tailored support and monitoring to manage their risk later in life.

There are many factors that can affect our risk of heart disease, some that can be controlled, treated or modified, such as blood pressure and cholesterol levels, and others that can’t be changed, such as age and family history.

Risk of heart disease is currently evaluated through assessment of cholesterol levels, smoking habits, family history and blood pressure and diabetes. However, emerging evidence shows that heart disease risk may be influenced by a wider variety of factors.

Previous research has found an association between low birthweight, which is usually defined as less than 2.5kg (5.5lbs), and a higher risk of heart disease. It is also known that conditions in the womb – such as preeclampsia and gestational diabetes – may also impact risk. However until now, it was not known whether birthweight alone could directly raise the risk of developing heart disease.

The team of researchers, led by Dr Maddalena Ardissino, Honorary Clinical Research Fellow at Imperial College London and NIHR Academic Clinical Fellow at the University of Cambridge, analysed data from nearly 300,000 participants of the Early Growth Genetics consortium and the UK Biobank.

Using Mendelian randomisation – a statistical technique that analyses genetic data to determine cause and effect – the team investigated the impact of birthweight on heart disease risk, independently of conditions in the womb which are known to affect birthweight. They also examined whether other risk factors could be influencing the relationship between low birthweight and heart disease risk.

The team found that low birthweight was directly associated with an increased risk of coronary artery disease, and that this relationship was independent of conditions in the womb. A reduction in birthweight by approximately 480g resulted in a 20 per cent increased risk of heart disease. They also found that throughout life, systolic blood pressure – the pressure when the heart is pumping blood through the arteries – plays a central role in this relationship.

The research highlights that closely monitoring and managing blood pressure – could be a key strategy to help people born with a lower birthweight reduce their risk of heart disease over the course of their lifetime. In addition, the team found that lower birthweight was protective against atrial fibrillation, a common type of irregular heart rhythm.

Dr Maddalena Ardissino, Honorary Clinical Research Fellow at the National Heart and Lung Institute, Imperial College London, said: “Low birthweight is a common pregnancy complication. Beyond its many short-term risks, our research highlights how it can influence long-term cardiovascular health in an important way.

“Understanding how birthweight is linked to heart health, and the risk factors at play, is an important step in improving cardiovascular risk prediction and providing personalised preventive care.”

Professor Sir Nilesh Samani, our Medical Director, said: “This research reveals, that weight at birth is inextricably linked to an individual’s risk of developing heart disease in their lifetime.

“Information about patients’ birthweight could be a valuable tool to help doctors build up a better picture of patients’ risk of heart disease, helping identify those who could benefit from closer monitoring or targeted intervention to help reduce their risk of heart disease.”

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