MATERNAL smoking during pregnancy, as well as DNA methylation (DNAm) smoking scores, may be associated with a reduced risk of islet autoimmunity (IA) and type 1 diabetes (T1D) in children at high risk, according to the results of a new study. This intriguing finding adds a layer of complexity to the longstanding debate about the effects of prenatal smoke exposure on child health.
The research, conducted using data from the Diabetes Autoimmunity Study in the Young cohort, explored how in utero smoke exposure, measured through both self-reported maternal smoking and DNA methylation-based smoking scores, correlates with the development of IA and T1D. The study included 205 IA cases and 206 controls, with 87 T1D cases and 88 controls, all matched for age, race/ethnicity, and sample availability.
The results were surprising: maternal smoking during pregnancy and higher DNAm smoking scores were both inversely associated with the risk of IA and T1D. Specifically, maternal smoking was found to significantly lower the risk of IA, with an odds ratio (OR) of 0.24. Additionally, two DNAm smoking scores, Rauschert and McCartney, showed consistent inverse associations with both IA and T1D outcomes, with ORs ranging from 0.65 to 0.83 for each standard deviation increase in methylation scores.
These findings challenge previous assumptions about the harmful effects of maternal smoking and suggest a more complex relationship between in utero exposure and autoimmune risk in offspring. While further research is necessary to explore the underlying mechanisms, the study adds valuable insights into the environmental factors that may influence the onset of T1D.
Reference:
Vanderlinde LA et al. DNA Methylation Smoking Scores and Risk of Islet Autoimmunity and Type 1 Diabetes. Diabetes Care. 2025:dc250330.
