Polymethylation scores for prenatal maternal smoke exposure persist until age 15 and are detected in saliva in the Fragile Families and Child Wellbeing cohort.

Prenatal maternal smoking is associated with low birthweight, neurological disorders, and asthma in exposed children. DNA methylation signatures can function as biomarkers of prenatal smoke exposure. However, the robustness of DNA methylation signatures across child ages, genetic ancestry groups, or tissues is not clear. Using coefficients from a meta-analysis of prenatal smoke exposure and DNA methylation in newborn cord blood, we created polymethylation scores of saliva DNA methylation from children at ages 9 and 15 in the Fragile Families and Child Wellbeing study. In the full sample at age 9 (n = 753), prenatal smoke exposure was associated with a 0.51 (95%CI: 0.35, 0.66) standard deviation higher polymethylation score. The direction and magnitude of the association was consistent in European and African genetic ancestry samples. In the full sample at age 15 (n = 747), prenatal smoke exposure was associated with a 0.48 (95%CI: 0.32, 0.63) standard deviation higher polymethylation score, and the association was attenuated among the European and Admixed-Latin genetic ancestry samples. The polymethylation score classified prenatal smoke exposure accurately (AUC age 9 = 0.77, age 15 = 0.76). Including the polymethylation score increased the AUC of base model covariates by 5 (95% CI: (2.1, 7.2)) percentage points, while including a single candidate site in the AHRR gene did not (P-value = 0.19). Polymethylation scores for prenatal smoking were portable across genetic ancestries and more accurate than an individual DNA methylation site. Polymethylation scores from saliva samples could serve as robust and practical biomarkers of prenatal smoke exposure.

Dietary patterns associated with dental caries in adults in the United States.

OBJECTIVES: Dental caries experience, which affects 91% of US adults, is a consequence of a carious process influenced by diet. Although individual foods have been implicated, we hypothesized that dietary patterns might be important predictors of caries presence. METHODS: We analysed data from 4467 people ≥18 years old participating in the 2013-2014 National Health and Nutrition Examination Survey, a nationally representative sample of the US population. Data from 24-hour dietary recalls were classified into standard food categories and reduced to three dietary patterns using principal components (PCs) analysis. We used regression to model the log-transformed decayed, missing and filled teeth (DMFT) score and the prevalence of any caries experience by quartiles of PC scores, controlling for potential confounders. Dietary patterns differed by age with respect to dental caries so 18-30-year-olds (n = 1074) and >30-year-olds (n = 3393) were analysed separately. RESULTS: Similar dietary patterns existed among individuals aged 18-30 and >30 years, but the prevalence of DMFT score >0 and the median of DMFT was greater in those >30:78.7% (95% CI: 76.1, 81.3) vs 92.6% (95% CI: 91.4, 93.7) and 4 (95% CI: 4, 5) vs 12 DMFT (95% CI: 11, 13), respectively. In those 18-30, no dietary pattern was associated with greater prevalence or severity of dental caries experience. Among those >30, the prevalence of DMFT>0 was higher by 2% for those in each subsequent quartile of a diet high in sugar-sweetened beverages and sandwiches (adjusted PR: 1.02, 95% CI: 1.001, 1.03)-thus, the prevalence of dental caries experience was 6% higher among those in the uppermost quartile than in the lowest quartile. For every subsequent quartile in the same pattern, there was a 1.98% higher (95% CI: 0.15, 3.85) DMFT score. However, analysis using the two strongest loading food groups from any of the PCs did not identify any predictors of caries experience. CONCLUSIONS: Dietary patterns were associated with the prevalence of dental caries experience, with differing findings by age. Although effect sizes were small, the population impact may be substantial. While food groups high in sugar were associated with caries prevalence and severity, associations were more apparent in the context of overall diet. Prospective studies are needed to confirm whether particular dietary patterns are causally related to the development of dental caries.