A UK birth cohort study that tracked participants from birth has linked contracting a lower respiratory tract infection (LRTI) such as bronchitis or pneumonia in early childhood with nearly double the risk of dying from respiratory disease by 73 years, although the absolute risk was low: 2% vs 1% in those without a history of childhood LRTI.
In the study, published yesterday in The Lancet, a team led by Imperial College London investigators analyzed data from the Medical Research Council National Survey of Health and Development. The survey was made up of a nationally representative group of 5,362 people in England, Scotland, and Wales recruited at birth in March 1946.
Of the 5,362 participants, 4,032 were still participating in the study at age 20 to 25 years, and 3,589 participants who were 26 years old in 1972 were included in the survival analyses from 1972 to 2019, when they were 73. Maximum follow-up was 47.9 years.
8% of premature deaths due to respiratory cause
Among the 3,589 participants in the analysis, 25% had an LRTI before age 2 years and were at higher risk for dying from respiratory disease by age 73 than those who didn't have an LRTI (2.1% vs 1.1%, for an increased risk of 93%) after adjustment for factors such as childhood socioeconomic status and adults smoking status.
By the end of the study, 19% of participants had died before age 73. Among these 674 premature adult deaths, 8% died of a respiratory disease, mostly chronic obstructive pulmonary disease (COPD). The result translated to a population attributable risk of 20.4% and 179,188 excess deaths (1 in 5 adult respiratory deaths) from 1972 to 2019.
For reference, adult smoking-related diseases were responsible for almost 3 of 5 deaths (57.7%) from respiratory disease over the same period (507,223 of 878,951 deaths).
The authors noted that other risk factors (eg, premature birth, parental smoking) may have also influenced the increased risk.
Optimizing childhood health
In an Imperial College London news release, lead author James Allinson, BMBCh, PhD, said that the focus of the prevention of adult respiratory disease has focused on lifestyle 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," he said. "To prevent the perpetuation of existing adult health inequalities we need to optimise childhood health, not least by tackling childhood poverty."