A one-of-its-kind assessment of 8 decades' worth of UK data show a lower respiratory tract infection by age 2 increases risk of premature adult death by 93%.
Children who experience a lower respiratory tract infection are at a 93% increased risk of premature adult death due to a respiratory disease than those who do not, according to new data from the UK.
In a first-of-its-kind longitudinal observational cohort assessment of patients across 8 decades in the UK, a team of Imperial College London investigators reported that infant-age respiratory tract infections including bronchitis or pneumonia result in a nearly two-fold increased risk of death due to respiratory disease by age 73. What’s more, these early-impacted patients have comprised more than 20% of the premature adult deaths due to respiratory disease among the England and Wales populations from 1972 – 2019.
Led by Dr. James P. Allinson, consultant respiratory physician at the Royal Brompton Hospital, investigators conducted their analysis to estimate the link between early pediatric lower respiratory tract infections and overall risk and burden of premature adult deaths due to respiratory disease. While common preventive strategies for adult-age respiratory disease have focused on adult-age exposure avoidance like smoking cessation, it’s been historically hypothesized that childhood exposure to respiratory infections may predispose adults to future burdens.
“Many studies have linked lower respiratory tract infections in early childhood to reduced adult lung function, but there have been no life-spanning studies quantifying their potential contribution to premature adult mortality from respiratory disease,” they wrote.
Allinson and colleagues conducted a prospective, longitudinal observational analysis of nationally-representative cohort data from the Medical Research Council National Survey of Health and Development (NSHD), in which patients were recruited at birth in England, Scotland and Wales in March 1946. The team sought an outcome of association between lower respiratory tract infection among children <2 years old and death from respiratory disease from age 26 – 73 years.
Hazard ratios (HRs) and population-associated risks linked to such childhood infections were estimated with competing risks Cox proportional hazards models, with adjustments made for childhood socioeconomic statuses, home overcrowding, birthweight, sex and smoking status at ages 20 – 25 years. Aside from comparing the mortality of this cohort with national mortality rates, the team additionally estimated the total and rate of excess deaths due to this association among the national population.
The original survey recruited 5362 participants in March 1946; approximately three-fourths (n = 4032) continued participation at ages 20 – 25 years. Investigators excluded approximately 500 participants due to incomplete early childhood data, smoking status or mortality. The final analysis from 1972 to present included 3589 participants aged 26 years old; 51% were male, and maximum follow-up time was 47.9 years.
The team observed 913 (25%) patients with a lower respiratory tract infection during early childhood; they were at a significantly increased risk of dying from a respiratory disease by 73 years old those without such an infection (adjusted HR, 1.93; 95% CI, 1.10 – 3.37; P = .021).
Overall, patients who experienced an early childhood lower respiratory tract infection comprised 20.4% of all premature adult deaths due to respiratory disease (95% CI, 3.8 – 29.8). Investigators believe this population was responsible for 179,188 excess deaths across England and Wales from 1972 – 2019 (95% CI, 33,806 – 261,519).
Investigators noted that impaired adult lung function may be a “plausible mediatory linking early childhood infection to respiratory-cause adult mortality.”
“Infection might disrupt or reflect already disrupted childhood lung development, leading to children reaching lower peak lung function as adults, increasing the risk of respiratory morbidity and mortality,” they wrote. “Importantly, the relationship between early childhood LRTI and adult lung function appears modifiable by adolescent smoking and asthma, which perhaps prevent naturally occurring catch-up growth during adolescence.”
As such, they stressed the importance of identifying young children with lower respiratory tract infections and seeking means to optimize their respiratory health and development into adulthood.
“Childhood poverty, a broad driver of childhood respiratory disease, remains common globally, and although this does not explain the link between early childhood (lower respiratory tract infection) and subsequent adult mortality, poorer environmental conditions predisposed children in the NSHD to develop respiratory infection in the first place,” they concluded. “Addressing childhood poverty worldwide, besides improving child health, could help avoid the perpetuation of health inequities across life, down generations, and between communities.”