Expiratory airflow in late adolescence and early adulthood in individuals born very preterm or with very low birthweight compared with controls born at term or with normal birthweight: a meta-analysis of individual participant data

Abstract

Background Maximal expiratory airflow peaks early in the third decade of life, then gradually declines with age. The pattern of airflow through adulthood for individuals born very preterm (at <32 weeks' gestation) or with very low birthweight (<1501 g) is unknown. We aimed to compare maximal expiratory airflow in these individuals during late adolescence and early adulthood with that of control individuals born with normal birthweight (>2499 g) or at term. MethodsWe did a meta-analysis of individual participant data from cohort studies, mostly from the pre-surfactant era. Studies were identified through the Adults born Preterm International Collaboration and by searching PubMed and Embase (search date May 25, 2016). Studies were eligible if they reported on expiratory flow rates beyond 16 years of age in individuals born very preterm or with very low birthweight, as well as controls born at term or with normal birthweight. Studies with highly selected cohorts (eg, only participants with bronchopulmonary dysplasia) or in which fewparticipants were born very preterm or with very low birthweight were excluded. De-identified individual participant data from each cohort were provided by the holders of the original data to a central site, where all the data were pooled into one data file. Any data inconsistencies were resolved by discussion with the individual sites concerned. Individual participant data on expiratory flow variables (FEV₁, forced vital capacity [FVC], FEV₁/FVC ratio, and forced expiratory flow at 25-75% of FVC [FEF 25-75% ]) were converted to Z scores and analysed with use of generalised linear mixed models in a one-step approach. Findings Of the 381 studies identified, 11 studies, comprising a total of 935 participants born very preterm or with very low birthweight and 722 controls, were eligible and included in the analysis. Mean age at testing was 21 years (SD 3·4; range 16-33). Mean Z scores were close to zero (as expected) in the control group, but were reduced in the very preterm or very low birthweight group for FEV₁ (-0·06 [SD 1·03] vs -0·81 [1·33], mean difference -0·78 [95% CI -0·96 to -0·61], p<0·0001), FVC (-0·15 [0·98] vs -0·38 [1·18], -0·25 [-0·40 to -0·10], p=0·0012), FEV₁/FVC ratio (0·14 [1·10] vs -0·64 [1·35], -0·74 [-0·85 to -0·64], p<0·0001), and FEF 25-75% (-0·04 [1·10] vs -0·95 [1·47], -0·88 [-1·12 to -0·65], p<0·0001). Similar patterns were observed when we compared the proportions of individuals with values below the fifth percentile.Interpretation Individuals born very preterm or with very low birthweight are at risk of not reaching their full airway growth potential in adolescence and early adulthood, suggesting an increased risk of chronic obstructive pulmonary disease in later adulthood.

Long-term motor outcomes of very preterm and/or very low birth weight individuals without cerebral palsy: A review of the current evidence

“…While these differences have usually not been seen in studies measuring physical activity by accelerometry [79], they are accompanied by findings of lower lean body mass [80] and physical fitness [74,81]. They may be a result of a vicious cycle where poor motor coordination have been suggested to play a key role, perhaps together with lower pulmonary airflow [64] and poor visual acuity [39]. This may lead to lower physical self-confidence and perceived physical ability [82], together making physical activity less rewarding, leading to lower degrees of physical activity and may also aggravate the lower exercise capacity and lower lean body mass.…”

“…Cognitive abilities have been extensively studied and remain 0.70 to 0.86 SD lower in VP/VLBW children than in controls [63]. Other examples include pulmonary airflow, showing a similar difference, 0.80 SD, in 1-s forced expiratory flow in VLBW adults [64], whereas the difference in blood pressure is smaller, corresponding to 0.3 SD [65,66]. Together these numbers indicate that poorer motor skills, even without the presence of manifest CP, are an essential part of the "VP/VLBW phenotype" at least in childhood.…”

Twenty‐five years of Respirology: Advances in COPD

“…For most, peak lung function is achieved in early adulthood, after which lung function gradually declines with ageing . There is compelling evidence that individuals born preterm or with a very low birthweight, or who experience recurrent or severe lung infection during childhood, never reach their full airway growth potential in adolescence and early adulthood, which significantly increases their risk of COPD in adult life . Such individuals will develop COPD later on in life, even though their rate of lung function loss is the same as that of the average person in the community.…”

“…2 There is compelling evidence that individuals born preterm or with a very low birthweight, or who experience recurrent or severe lung infection during childhood, never reach their full airway growth potential in adolescence and early adulthood, which significantly increases their risk of COPD in adult life. 3 Such individuals will develop COPD later on in life, even though their rate of lung function loss is the same as that of the average person in the community. An important byproduct of this observation is the concept of 'early COPD', which refers to the genesis of COPD among individuals younger than 50 years of age who have ≥10 pack-years of smoking history and any of the following abnormalities: (i) early airflow limitation (post-bronchodilator forced expiratory volume in 1 s/ forced vital capacity (FEV 1 /FVC) <lower limit of normal), (ii) compatible computed tomography (CT) abnormalities and (iii) rapid decline in FEV 1 (>60 mL/ year).…”

Voice and Exercise Related Respiratory Symptoms in Extremely Preterm Born Children After Neonatal Patent Ductus Arteriosus

“…This practice inevitably leads to diagnostic errors, and is particularly unfortunate in EP-born individuals, given their wide causal repertoire (9)(10)(11). For example, bronchial obstruction and hyperresponsiveness are well described features after EP-birth as well as in asthma (12)(13)(14)(15)(16). Although linked to different immunological profiles (14,(16)(17)(18)(19), large proportions of EPborn children are exposed to asthma medication (20).…”