Distinct trajectories of lung function from childhood to mid-adulthood

RATIONALE

Life course trajectories of lung function development and decline influence the risk for lung disease but are poorly documented.

OBJECTIVE

To document lung function trajectories from childhood to mid-adult life.

METHODS

We modelled forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC at ages 9, 11, 13, 15, 18, 21, 26, 32, 38 and 45 years from a population-based cohort using latent profile analysis to identify distinct subgroups of participants with similar lung function trajectories. Regression analyses were used to assess associations between the trajectories, early life factors and postbronchodilator airflow obstruction at age 45.

RESULTS

Among 865 participants with ≥6 measures of lung function, we identified 10 distinct FEV1 trajectories. Most were approximately parallel except for a childhood airway hyper-responsiveness-related persistently low trajectory (3% of study population); two accelerated-decline trajectories, one of which (8%) was associated with smoking and higher adult body mass index (BMI) and a catch-up trajectory (8%). Findings for FEV1/FVC trajectories were similar. Nine trajectories were identified for FVC: most were also approximately parallel except for a higher BMI-related accelerated-decline trajectory. The three FEV1 trajectories leading to the lowest FEV1 values comprised 19% of the cohort but contributed 55% of airflow obstruction at age 45.

CONCLUSIONS

Lung function trajectories to mid-adult life are largely established before adolescence, with a few exceptions: a childhood airway hyper-responsiveness-related persistently low trajectory, which starts low and gets worse with age, and accelerated adult decline trajectories associated with smoking and obesity. Adverse trajectories are associated with a high risk of airflow obstruction in mid-adult life.

Neighbourhood green and blue spaces and allergic sensitization in children: A longitudinal study based on repeated measures from the Generation XXI cohort

Evidence on the effect of natural environments on atopy in children is limited and inconsistent, disregarding the time-varying and cumulative exposures throughout the life course. To assess critical periods of exposure as well as the effect of longitudinal trajectories of exposure to green and blue spaces on the development of allergic sensitization in children at the age of 10 years. A longitudinal study was conducted involving 730 children enrolled in Generation XXI, a population-based birth cohort from the Porto Metropolitan Area (Portugal). Food and aeroallergens sensitization were evaluated at 10 years of age using Phadiatop Infant, Phadiatop fx1 and fx22 ImmunoCAP (Thermo Fisher Scientific, Uppsala, Sweden). Residential Normalized Difference Vegetation Index (NDVI) and distance to the nearest blue space (sea, river) were assessed using a Geographic Information System. Latent class linear mixed models were fitted to determine longitudinal trajectories of exposure. Associations were estimated using Cox proportional hazards regression models and expressed using hazard ratios (HR) and 95% confidence intervals (95% CI). Residing in neighbourhoods surrounded by more vegetation at 10 years, as well as lifetime exposure to a trajectory of higher levels of NDVI, were associated with a lower risk of allergic sensitization [HR (95% CI) = 0.095 (0.011, 0.823) and HR (95% CI) = 0.539 (0.301, 0.965), respectively]. Our findings support a role for both longitudinal, but particularly late-childhood, exposure to green spaces, in the prevention of allergic sensitization in children.

Burden of disease attributable to second-hand smoke exposure: A systematic review

Our aim was to provide a systematic review of studies on the burden of disease due to second-hand smoke (SHS) exposure, reviewing methods, exposure assessment, diseases causally linked to SHS, health outcomes, and estimates available to date. A literature review of studies on the burden of disease from SHS exposure, available in PubMed and SCOPUS, published 2007-2018 in English language, was carried out following the PRISMA recommendations. Overall, 588 studies were first identified, and 94 were eligible. Seventy-two studies were included in the systematic review. Most of them were based on the comparative risk assessment approach, assessing SHS exposure using mainly surveys on exposure at home/workplaces. Diseases more frequently studied were: lung cancer, ischemic heart disease, stroke, chronic obstructive pulmonary disease, asthma and breast cancer in adults; lower respiratory tract infection, otitis media, asthma, sudden infant death syndrome and low birth weight in children. The SHS exposure assessment and the reported population attributable fractions (PAF) were largely heterogeneous. As an example, the PAF from lung cancer varied between 0.6% and 20.5%. Moreover, PAF were estimated applying relative risks and SHS exposures with no consistent definitions or with different age classes. The research gap on the SHS exposure burden is shrinking. However, estimates are not yet available for a number of countries, particularly the Middle Eastern and African countries, and not all diseases with the strongest evidence of causation, such as sudden infant death syndrome, have been explored. Moreover, in some cases the applied methodology revealed relatively low quality of data.