Research Associate Professor Vanderbilt University Medical Center Nashville, Tennessee, United States
Background: Gestational diabetes (GDM) is associated with metabolic derangements and other systemic processes (e.g., inflammation and oxidative stress) that may disrupt fetal development and contribute to suboptimal respiratory and immune health in offspring. In prior studies, GDM has been associated with child asthma, but studies on GDM and lung function are limited. Objective: To determine the association between GDM and child lung function and asthma at age 8-9. Design/Methods: We conducted a cohort study of mothers and children enrolled in the Conditions Affecting Neurocognitive Development in Early Childhood (CANDLE) cohort (births 2007-2011; Memphis, TN) and followed to 8-9 years of age. GDM was determined by medical chart review. We measured lung function, including forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC), using spirometry (n=725). Lung function z-scores for FEV1, FVC and FEV1/FVC were calculated using sex-and-age-specific reference equations. We assessed current asthma using the International Study of Asthma and Allergies in Childhood questionnaire. We estimated associations between GDM status and respiratory outcomes as the beta coefficient (B) and 95% confidence interval (CI) for lung function z-scores, and the odds ratio (OR) and CI for current asthma using multivariable regression, adjusting for maternal age, race, prenatal tobacco, parity, asthma history, pre-pregnancy body mass index, education and child sex and age. Lung function models were also adjusted for child height. Lastly, we performed a post hoc mediation analysis of current asthma in the association between GDM and FEV1. Results: Of 725 dyads, 45 (6%) women had GDM. The median (interquartile range) FEV1, FVC and FEV1/FVC z-scores were –0.46 (-1.13, 0.23), -0.412 (-1.11, 0.31), and -0.08 (-0.82, 0.62), respectively. With covariate adjustment, children with prenatal exposure to GDM had lower FEV1 (B: -0.27; CI: -0.55, 0.01) and increased odds of current asthma (prevalence=13%) (OR: 2.47; CI: 1.30, 4.70). We did not observe any difference in FVC (B: -0.09; CI: -0.36, 0.18) or FEV1/FVC (B: -0.23; CI: -0.59, 0.13) by GDM exposure. We observed evidence that current asthma may be a partial mediator of the association between GDM and FEV1 (average causal mediation effect: –0.07; CI: -1.47, -0.01).
Conclusion(s): In these data, GDM was associated with lower FEV1 in offspring aged 8-9, and current asthma may be an intermediate in this association. GDM may be an important risk factor for childhood asthma and subclinical airway obstruction.
