Plasma concentration of trimethylamine-N-oxide tied to gestational diabetes mellitus
Plasma trimethylamine-N-oxide (TMAO) concentrations are positively associated with gestational diabetes mellitus (GDM), according to the findings of a phase II study.
A total of 866 participants (433 GDM patients and 433 matched controls) with fasting blood samples collected at the time of GDM screening (24–32 weeks of gestation) were included in the initial phase of the study. In addition, 276 GDM patients and 552 matched controls who provided fasting blood samples before 20 weeks of gestation and underwent GDM screening during 24–32 weeks of gestation were included in an independent-phase study, which was nested within a prospective cohort study.
The two studies were both conducted in Wuhan, China. GDM incidence in the cohort study was 10.8 percent. A stable isotope dilution liquid chromatography–tandem mass spectrometry determined plasma TMAO concentrations. An oral-glucose-tolerance test was used to diagnose GDM according to the American Diabetes Association criteria.
Comparing the highest TMAO quartile with the lowest quartile in the initial case-control study, the adjusted odds ratio (OR) of GDM was 1.94 (95 percent CI, 1.28–2.93). Each SD increase in In-transformed plasma TMAO correlated with 22-percent (5–41 percent) higher odds of GDM.
In the nested case-control study, women in the highest quartile vs those in the lowest quartile also had greater odds of GDM (adjusted OR, 2.06; 1.28–3.31). The adjusted OR for GDM per SD increase of In-transformed plasma TMAO was 1.26 (1.08–1.47).
Further studies are needed to explain the underlying mechanisms, according to the authors.