Prevalence of childhood wheeze and modified DNA methylation at 7 years of age according to maternal folate levels during pregnancy in the Hokkaido Study

• DOI: 10.1111/pai.13425
• Publication Date: 2020-12-04T07:34:51Z
• Authors: Chihiro Miyashita; Atsuko Araki; Ryu Miura; Yu Ait Bamai; Sumitaka Kobayashi; Sachiko Itoh; Kumiko Ito; Meng‐Shan Tsai; Reiko Kishi
• Keywords: 2. Zero hunger; DNA methylation; childhood wheeze; 490; Infant, Newborn; maternal folate; birth cohort; asthma; DNA Methylation; 3. Good health; 03 medical and health sciences; Folic Acid; 0302 clinical medicine; Pregnancy; Case-Control Studies; Prevalence; Humans; Female; pregnancy; Child; case-control; folate acid; Respiratory Sounds

AbstractBackgroundA high dose of folic acid during pregnancy may increase the risk of asthma, wheezing, and respiratory disease in childhood. Folate acid can modify inflammation and immune susceptibility of offspring with some epigenetic differentiation, including DNA methylation. This study evaluated associations between maternal folate levels during pregnancy and childhood wheezing; furthermore, the study assessed whether maternal folate‐modified DNA methylation is related to asthma.MethodsParticipants in the current study were 6651 mother‐child pairs who had complete data on characteristics and who had completed at least one of the International Study of Asthma and Allergies in Childhood questionnaires when the child was 1, 2, 4, and 7 years of age. Moreover, a case‐control study to assess DNA methylation at 7 years of age was conducted among 136 children who experienced wheezing and a control group of 139 children with no history of allergies.ResultsThe median of maternal serum was 16.76 nmol/L, assayed by chemiluminescent immunoassay. We found significantly increased adjusted odds ratios of childhood wheezing at 2 years age according to maternal folate levels, compared with the lowest folate quartile (odds ratio [95% confidence interval] = highest; 1.27 [1.03, 1.56], and second, 1.27 [1.05, 1.55]); however, no changes were observed at 1, 4, and 7 years of age. In a case‐control study, no association of maternal folate levels with DNA methylation was observed.ConclusionOur results suggest that maternal folate did not affect persistent wheezing in school‐aged children, or DNA methylation of gasdermin B, orosomucoid‐like 3, and Ikaros family zinc finger 3 at 7 years of age.