Preconceptional Maternal Bile Acids and Birth Weight of Neonates

Intrauterine exposure to long-chain perfluorocarboxylic acids (PFCAs) were associated with reduced primary bile acids in three-year-old children: Findings from a prospective birth cohort study

Bile acids (BAs) play a crucial role in lipid metabolism of children. However, the association between per- and polyfluoroalkyl substance (PFAS) exposure and BAs in children is scarce. To address this need, we selected 252 children from the Maoming Birth Cohort and measured 32 PFAS, encompassing short- and long-chain perfluorocarboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs) in the cord blood. Additionally, we analyzed nine primary and eight secondary BAs in the serum of three-year-old children. Generalized linear models with FDR-adjusted and Bayesian kernel machine regression (BKMR) were used to explore the associations of individual and mixture effects of PFAS and BAs. We found negative associations between cord blood long-chain PFCAs exposure and serum primary BAs in three-year-old children. For example, one ln-unit (ng/mL) increase of perfluoro-n-tridecanoic acid (PFTrDA), perfluoro-n-undecanoic acid (PFUnDA) and perfluoro-n-decanoic acid (PFDA) were associated with decreased taurochenodeoxycholic acid, with estimated percentage change of -24.28% [95% confidence interval (CI): -36.75%, -9.35%], -25.84% (95% CI: -39.67%, -8.83%), and -22.97% (95% CI: -34.45%, -9.47%) respectively. Notably, the observed associations were more pronounced in children with lower vegetable intake. Additionally, the BKMR model also demonstrated a monotonical decline in primary BAs as the PFAS mixture increased. We provided the first evidence of the association between intrauterine exposure to PFAS and its mixture with BAs in children. Further large-sample-size studies are needed to verify this finding.

Preconception insulin resistance and neonatal birth weight in women with obesity: role of bile acids

RESEARCH QUESTION

Does maternal preconception insulin resistance affect neonatal birth weight among women with obesity? Is insulin resistance associated with circulating bile acids? Do bile acids influence the association between maternal preconception insulin resistance and neonatal birth weight?

DESIGN

An exploratory post-hoc analysis of the LIFEstyle randomized controlled trial comparing lifestyle intervention with conventional infertility treatment in women with a BMI of ≥29 kg/m². Fasting blood samples were collected at randomization and after 3 and 6 months in 469 women. Insulin resistance was quantified using the homeostasis model assessment of insulin resistance (HOMA-IR). Bile acid sub-species were determined by liquid chromatography with tandem mass spectrometry. Singletons were included (n = 238). Birth weight Z-scores were adjusted for age, offspring gender and parity. Multilevel analysis and linear regressions were used.

RESULTS

A total of 913 pairs of simultaneous preconception HOMA-IR (median [Q25; Q75]: 2.96 [2.07; 4.16]) and total bile acid measurements (1.79 [1.10; 2.94]) µmol/l were taken. Preconception HOMA-IR was positively associated with total bile acids (adjusted B 0.15; 95% CI 0.09 to 0.22; P < 0.001) and all bile acid sub-species. At the last measurement before pregnancy, HOMA-IR (2.71 [1.91; 3.74]) was positively related to birth weight Z-score (mean ± SD 0.4 ± 1.1; adjusted B 0.08; 95% CI 0.01 to 0.14; P = 0.03). None of the preconception bile acids measured were associated with birth weight.

CONCLUSION

Maternal preconception insulin resistance is an important determinant of neonatal birth weight in women with obesity, whereas preconception bile acids are not.