Abstract
Background Vitamin C (500 mg·day−1) supplementation for pregnant smokers has been reported to increase newborn pulmonary function and infant forced expiratory flows (FEFs) at 3 months of age. Its effect on airway function through 12 months of age has not been reported.
Objective To assess whether vitamin C supplementation to pregnant smokers is associated with a sustained increased airway function in their infants through 12 months of age.
Methods This is a pre-specified secondary outcome of a randomised, double-blind, placebo-controlled trial that randomised 251 pregnant smokers between 13 and 23 weeks of gestation: 125 to 500 mg·day−1 vitamin C and 126 to placebo. Smoking cessation counselling was provided. FEFs performed at 3 and 12 months of age were analysed by repeated-measures analysis of covariance.
Results FEFs were performed in 222 infants at 3 months and 202 infants at 12 months of age. The infants allocated to vitamin C had significantly increased FEFs over the first year of life compared to those allocated to placebo. The overall increased flows were 40.2 mL·s−1 for at FEF75 (75% of forced vital capacity (FVC)) (adjusted 95% CI for difference 6.6–73.8; p=0.025); 58.3 mL·s−1 for FEF50 (10.9–105.8; p=0.0081); and 55.1 mL·s−1 for FEF25–75 (9.7–100.5; p=0.013).
Conclusions In offspring of pregnant smokers randomised to vitamin C versus placebo, vitamin C during pregnancy was associated with a small but significantly increased airway function at 3 and 12 months of age, suggesting a potential shift to a higher airway function trajectory curve. Continued follow-up is underway.
Abstract
Vitamin C supplementation coupled with smoking cessation counselling for pregnant smokers may be a safe, inexpensive, and simple intervention to improve the airway function of their offspring through 12 months of age https://bit.ly/3fa8q2X
Footnotes
This article has an editorial commentary: https://doi.org/10.1183/13993003.02770-2020
This article has supplementary material available from erj.ersjournals.com
This study is registered at ClinicalTrials.gov with identifier NCT01723696. Individual de-identified participant data, including data dictionaries, that underlie the results reported in this article will be shared. The study protocol, statistical analysis plan and analytic code will be available. The data will be available beginning 9 months and ending 36 months following article publication. It will be made available to researchers who provide a methodologically sound proposal to achieve aims in the approved proposal. Proposals should be directed to DCC@ohsu.edu.
Author contributions: Conception and design: all authors. Analysis and interpretation: C.T. McEvoy, A. Vu, B.S. Park, D.F. Kraemer, E.R. Spindel, C.D. Morris and R.S. Tepper. Drafting the manuscript: C.T. McEvoy, B.S. Park, D.F. Kraemer, A. Vu, E.R. Spindel, C.D. Morris and R.S. Tepper.
Support statement: Supported by the NHLBI (R01 HL105447 and R01 HL 105460) with cofunding from the Office of Dietary Supplements (ODS) and by P51 OD011092565 and NIH UH3 OD023288. Additional support from the Oregon Clinical Translational Research Institute funded by the National Center for Advancing Translational Sciences (5 UL1 TR000128 and 5 UL1 TR002369). Funding information for this article has been deposited with the Crossref Funder Registry.
Conflict of interest: C.T. McEvoy reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: L.E. Shorey-Kendrick reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: K. Milner reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: D. Schilling reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: C. Tiller reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: B. Vuylsteke reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: A. Scherman reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: K. Jackson reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: D.M. Haas reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: J. Harris reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: B.S. Park reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: A. Vu reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: D.F. Kraemer reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: D. Gonzales reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: C. Bunten has nothing to disclose.
Conflict of interest: E.R. Spindel reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: C.D. Morris reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
Conflict of interest: R.S. Tepper reports grants from NHLBI (R01HL105447 and R01 HL105460), Office of Dietary Supplements, P51 OD011092565, NIH (UH3 OD023288) and UL1TR000128, during the conduct of the study.
- Received November 14, 2019.
- Accepted June 4, 2020.
- Copyright ©ERS 2020