{"doi":"10.1186/s13148-024-01644-8","title":"Improvements in lung function following vitamin C supplementation to pregnant smokers are associated with buccal DNA methylation at 5 years of age","abstract":"Abstract Background We previously reported in the “Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function” randomized clinical trial (RCT) that vitamin C (500 mg/day) supplementation to pregnant smokers is associated with improved respiratory outcomes that persist through 5 years of age. The objective of this study was to assess whether buccal cell DNA methylation (DNAm), as a surrogate for airway epithelium, is associated with vitamin C supplementation, improved lung function, and decreased occurrence of wheeze. Methods We conducted epigenome-wide association studies (EWAS) using Infinium MethylationEPIC arrays and buccal DNAm from 158 subjects (80 placebo; 78 vitamin C) with pulmonary function testing (PFT) performed at the 5-year visit. EWAS were performed on (1) vitamin C treatment, (2) forced expiratory flow between 25 and 75% of expired volume (FEF 25–75 ), and (3) offspring wheeze. Models were adjusted for sex, race, study site, gestational age at randomization (≤ OR > 18 weeks), proportion of epithelial cells, and latent covariates in addition to child length at PFT in EWAS for FEF 25–75 . We considered FDR p < 0.05 as genome-wide significant and nominal p < 0.001 as candidates for downstream analyses. Buccal DNAm measured in a subset of subjects at birth and near 1 year of age was used to determine whether DNAm signatures originated in utero, or emerged with age. Results Vitamin C treatment was associated with 457 FDR significant ( q < 0.05) differentially methylated CpGs (DMCs; 236 hypermethylated; 221 hypomethylated) and 53 differentially methylated regions (DMRs; 26 hyper; 27 hypo) at 5 years of age. FEF 25–75 was associated with one FDR significant DMC (cg05814800), 1,468 candidate DMCs ( p < 0.001), and 44 DMRs. Current wheeze was associated with 0 FDR-DMCs, 782 candidate DMCs, and 19 DMRs ( p < 0.001). In 365/457 vitamin C FDR significant DMCs at 5 years of age, there was no significant interaction between time and treatment. Conclusions Vitamin C supplementation to pregnant smokers is associated with buccal DNA methylation in offspring at 5 years of age, and most methylation signatures appear to be persistent from the prenatal period. Buccal methylation at 5 years was also associated with current lung function and occurrence of wheeze, and these functionally associated loci are enriched for vitamin C associated loci. Clinical trial registration ClinicalTrials.gov, NCT01723696 and NCT03203603.","journal":"Clinical Epigenetics","year":2024,"id":455415,"datarank":0.34714994410542327,"base_score":1.9459101490553132,"endowment":1.9459101490553132,"self_citation_contribution":0.29188652235829704,"citation_network_contribution":0.05526342174712623,"self_endowment_contribution":0.29188652235829704,"citer_contribution":0.05526342174712623,"corpus_percentile":null,"corpus_rank":null,"citation_count":6,"citer_count":4,"citers_with_citation_signal":3,"citers_with_endowment":3,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9475,"is_data_producer":true,"deposit_databanks":{"ClinicalTrials.gov":["NCT01723696","NCT03203603"]},"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":327168,"name":"Cindy T. McEvoy","orcid":"0000-0001-8501-8813","position":1,"is_corresponding":false},{"id":487460,"name":"Kristin Milner","orcid":null,"position":2,"is_corresponding":false},{"id":1279588,"name":"Julia Harris","orcid":null,"position":3,"is_corresponding":false},{"id":865245,"name":"Julie Brownsberger","orcid":null,"position":4,"is_corresponding":false},{"id":355870,"name":"Robert S. Tepper","orcid":"0000-0003-3322-5903","position":5,"is_corresponding":false},{"id":261354,"name":"Byung Park","orcid":null,"position":6,"is_corresponding":false},{"id":314329,"name":"Lina Gao","orcid":"0000-0001-9382-0419","position":7,"is_corresponding":false},{"id":487462,"name":"Annette Vu","orcid":null,"position":8,"is_corresponding":false},{"id":395072,"name":"Cynthia D. Morris","orcid":"0000-0003-1581-9054","position":9,"is_corresponding":false},{"id":487465,"name":"Eliot R. Spindel","orcid":null,"position":10,"is_corresponding":false},{"id":486266,"name":"Lyndsey E. Shorey‐Kendrick","orcid":"0000-0001-8060-0097","position":0,"is_corresponding":true}],"reference_count":87,"raw_metadata":null,"created_at":"2026-07-19T02:03:17.458329Z","pmid":"38413986","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}