Knihtilä HM, Huang M, Prince N, Stubbs BJ, Carey VJ, Laranjo N, Mirzakhani H, Zeiger RS, Bacharier LB, O'Connor GT, Litonjua AA, Weiss ST, Lasky-Su J. Maternal vitamin D status modifies the effects of early life tobacco exposure on child lung function.
J Allergy Clin Immunol 2023;
151:556-564. [PMID:
36400177 PMCID:
PMC9905288 DOI:
10.1016/j.jaci.2022.10.030]
[Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/03/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND
Prior studies suggest that vitamin D may modify the effects of environmental exposures; however, none have investigated gestational vitamin D and cumulative tobacco smoke exposure (TSE) throughout pregnancy and early life.
OBJECTIVES
This study investigated the effects of early life TSE on child lung function and the modulatory effects of gestational vitamin D on this association.
METHODS
The VDAART (Vitamin D Antenatal Asthma Reduction Trial) recruited nonsmoking pregnant women and followed the mother-child pairs to age 6 years. TSE was assessed with questionnaires and plasma cotinine measurements in the mothers (10-18 and 32-38 gestational weeks) and children (1, 3, and 6 years). Cumulative TSE was calculated from the repeated cotinine measurements. 25-hydroxyvitamin D (25[OH]D) levels were measured at 10-18 and 32-38 gestational weeks. Lung function was assessed at 6 years with spirometry and impulse oscillometry.
RESULTS
Of the 476 mother-child pairs, 205 (43%) had increased cotinine levels at ≥1 time point. Cumulative TSE was associated with decreased FEV1 (β = -0.043 L, P = .018) and increased respiratory resistance at 5 Hz (R5; β = 0.060 kPa/L/s, P = .002). This association persisted in subjects with insufficient (<30 ng/mL) 25(OH)D levels throughout pregnancy (β = 0.077 kPa/L/s, P = .016 for R5) but not among those with sufficient levels throughout pregnancy.
CONCLUSIONS
Cumulative TSE from pregnancy to childhood is associated with dose- and duration-dependent decreases in child lung function at 6 years even in the absence of reported maternal smoking. Gestational vitamin D may modulate this effect and have therapeutic potential for minimizing the adverse effect of TSE on lung throughout early life.
RANDOMIZED TRIAL
Maternal Vitamin D Supplementation to Prevent Childhood Asthma (VDAART); clinicaltrials.gov identifier: NCT00920621.
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