Respiratory diseases are a major cause of premature adult mortality worldwide. Current disease prevention strategies focus on harmful adult exposures. Common childhood exposures also influence adult respiratory health, but their contribution to premature adult mortality is unclear. Early childhood lower respiratory tract infection (LRTI) can disrupt lung development and increase the risk of developing chronic airway disease.
Researchers from Imperial College London have found that children with a lower respiratory tract infection (LRTI) by the age of two are almost twice as likely to die prematurely in adulthood from respiratory diseases.
This research, which covers more than 73 years, provides the most significant evidence to date that early respiratory health influences mortality later in life. Premature death from respiratory illness was over 2% for individuals with an LRTI in early childhood, compared to roughly 1% for the general population. After controlling for socioeconomic characteristics and smoking status, the findings were maintained.
Previous research has connected infant LRTIs to adult lung function deficits, asthma, and COPD. However, it is unknown if there is also a relationship too early death in adulthood. The findings remove the myth that adult deaths from respiratory diseases are determined solely by adult behavior, such as smoking, and emphasize the importance of preventing childhood respiratory infections and improving children’s health through targeted public health measures and healthcare interventions.
Researchers from University College London, Loughborough University, and the Royal Brompton and Harefield NHS Foundation Trust participated in the study. The study’s primary author is Dr. James Allinson of the National Heart and Lung Institute.
Dr. James Allinson, a lead author for the study from the National Heart & Lung Institute at Imperial College London, 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 optimize 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.”
Professor Rebecca Hardy, a co-author for the study from University College London and Loughborough University, said: “The results of our study suggest that efforts to reduce childhood respiratory infections could have an impact on tackling premature mortality from respiratory disease later in life. We hope that this study will help guide the strategies of international health organizations in tackling this issue.”
The study examines health and mortality records for 3,589 persons from 1946 to 2019 using data from a statewide British cohort study called The National Survey of Health and Development (NSHD). There were 913 lower respiratory infections among the 3,589 trial participants under the age of two.
Professor Nish Chaturvedi, a co-author for the study and PI of NSHD from University College London, said: “This study highlights the importance of the whole of life studies. As the UK’s longest-running nationally representative cohort study – the MRC NSHD, 1946 British Birth Cohort, is uniquely placed to investigate early life factors that can lead to premature mortality from respiratory disease in later life.”
Professor Rebecca Hardy, UCL, and Loughborough University said, “The results of our study suggest that efforts to reduce childhood respiratory infections could have an impact on tackling premature mortality from respiratory disease later in life.”
The researchers used a statistical model to estimate the association between a respiratory infection in early childhood and premature death from respiratory diseases in adulthood. They found that children who had an LRTI by the age of two were 93% more likely to die prematurely from respiratory illness as adults compared to those who had not. 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. Adult respiratory deaths linked to the smoking account for three in five deaths, or 507,223 excess deaths. The researchers note that other risk factors may have been unreported, such as parental smoking and being born prematurely.
The study was funded by NIHR Imperial Biomedical Research Centre, Royal Brompton and Harefield NHS Foundation Trust, and the UK Medical Research Council.