Respiratory disease in early childhood linked to higher risk of death in adulthood

Contracting a lower respiratory tract infection in early childhood is associated with a higher risk of dying from respiratory disease as an adult, according to new research.

A study published today in The Lancet, led by Dr James Allinson, consultant in respiratory medicine at Royal Brompton Hospital, and colleagues from Imperial College London, University College London and Loughborough University, has found that children who had a lower respiratory tract infection (LRTI), such as bronchitis or pneumonia, by the age of two were almost twice as likely to die prematurely in adulthood from respiratory diseases.

The research showed the rate of premature death from respiratory disease was about 2% for those who had a LRTI in early childhood, compared to around 1% for those who did not. The findings remained after adjusting for socioeconomic factors and smoking status.

Chronic respiratory diseases are a major public health problem, accounting for an estimated 3.9 million deaths, or 7 per cent of all deaths worldwide, in 2017. Most of these deaths were caused by chronic obstructive pulmonary disease (COPD) - a group of lung conditions that cause breathing difficulties, such as emphysema and chronic bronchitis.

Previous research has linked infant LRTIs to the development of adult lung function impairments, asthma, and COPD, but it has been unclear if there is also a link to premature death in adulthood. This first-of-its-kind study spans more than 73 years and provides the best evidence to date that early respiratory health has an impact on mortality later in life.

The findings challenge the misconception that adult deaths from respiratory diseases are determined only by behaviour in adulthood, such as smoking. The researchers say that this highlights the need to prevent childhood respiratory infection and improve the health of children, through targeted public health measures and health service interventions, such as vaccination, improving living conditions, and better diagnosis and treatment of underlying health conditions.

Dr James Allinson, lead author for the study, said: “Current preventative measures for adult respiratory disease mainly focus on adult lifestyle risk factors such as smoking. Linking one in five adult respiratory deaths to common infections many decades earlier in childhood shows the need to target risk well before adulthood.

“To prevent the perpetuation of existing adult health inequalities we need to optimise childhood health, not least by tackling childhood poverty. Evidence suggesting the early life origins of adult chronic diseases also helps challenge the stigma that all deaths from diseases such as COPD are related to lifestyle factors.”

The study uses data from a nationwide British cohort study called The National Survey of Health and Development (NSHD), which recruited individuals at birth in 1946, to look at health and death records for 3,589 people up until 2019. Of the 3,589 study participants, 913 suffered a lower respiratory infection before the age of two.

As the results show the childhood origins of health inequalities among adults who were born in the 1940s, improvements in childhood health and healthcare since this time may have led to better outcomes for children born today. However, evidence of the potentially lifelong consequences of poor childhood health highlights the need for renewed efforts to prevent LRTIs among children.

The researchers say this increased risk potentially accounts for 179,188 premature deaths in England and Wales between 1972 and 2019, or one in five deaths from respiratory disease.

In comparison, adult respiratory deaths linked to smoking account for three in five deaths from respiratory disease, or 507,223 excess deaths in England and Wales over the same period.

The study was funded by NIHR Imperial Biomedical Research Centre, Royal Brompton and Harefield NHS Foundation Trust (now part of Guy's and St Thomas' NHS Foundation Trust), Royal Brompton & Harefield Hospitals Charity and Imperial College Healthcare NHS Trust, and the UK Medical Research Council.