Objective: Investigation of serum bile acid profiles in pregnancies complicated by gestational diabetes mellitus (GDM) in a multi-ethnic cohort of lean and obese women.
Design: Prospective cohort study.
Setting: UK multicentre study.
Population or sample: Fasting serum from participants of European or South-Asian self-reported ethnicity from the PRiDE study between 23-31 weeks’ gestation.
Methods: Bile acids were measured using ultra-performance LC-MS/MS. Log-transformed data were analysed using linear regression in STATA/IC15.0.
Main Outcome Measures: Total bile acids (TBA), C4, fasting glucose and insulin.
Results: TBA were 1.327-fold (1.105-1.594) increased with GDM in European women (p=0.003). GDM women had 1.162-fold (1.002-1.347) increased levels of the BA synthesis marker C4 (p=0.047). In South-Asian women, obesity (but not GDM) increased TBA 1.522-fold (1.193-1.942, p=0.001). Obesity was associated with 1.420-fold (1.185-1.702) increased primary/secondary BA ratio (p<0.001) related to 1.355-fold (1.140-1.611) increased primary BA concentrations (p=0.001). TBA positively correlated with fasting glucose (p=0.039) in all women and to insulin (p=0.001) and HOMA-IR (p=0.001) in GDM women.
Conclusions: Serum BA homeostasis in late gestation depends on BMI and GDM in ethnicity-specific ways. This suggests ethnicity-specific aetiologies may contribute to metabolic risk in European and South-Asian women, with the relationship between BAs and insulin resistance of greater importance in European women. Further studies into ethnicity-specific precision medicine for GDM are required.