Association between serum thallium in early pregnancy and risk of gestational diabetes mellitus: The Ma’anshan birth cohort study

Abstract

BackgroundHigh blood glucose has been noted in case reports of acute thallium poisoning, however, effects of low-level exposure of thallium on risk of gestational diabetes mellitus (GDM) has not been explored yet. ObjectivesWe aimed to explore the association of serum thallium concentration (STC) in early pregnancy and risk of GDM. MethodsData of 3013 women from the Ma’anshan birth cohort study (MABC), China was used. STC was measured by inductively coupled plasma mass spectrometry (ICP-MS). Multivariate logistic regression was performed to the association of STC and risk of GDM. Stratified analysis was carried out according to maternal age and pre-pregnancy BMI. ResultsWe documented 383 incident GDM (12.7%). The STC ranged from 0.011 to 0.232 μg/L with a median of 0.062 μg/L. Women with advanced age and higher pre-pregnancy BMI tended to have higher level of STC. Individuals in GDM-group have higher level of STC than that in non-GDM group (P = 0.007). Maternal STC in early pregnancy was associated with risk of GDM, but the association attenuated to non-significance after adjusted for pre-pregnancy BMI. In the advanced age (>30 years) group, STC was significantly associated with risk of GDM in a dose-response manner (P for trend <0.05). Compared with the Quintile 1, the odds ratios (ORs) (95% confidence interval, CI) of Quintile 2, Quintile 3, Quintile 4, and Quintile 5 were 1.48 (0.62–3.53), 2.70 (1.21–6.03), 2.85 (1.29–6.31), 2.30 (1.05–5.05) in the most adjusted model (including pre-pregnancy BMI). ConclusionsOur study was the first study to demonstrate an association of maternal STC in early pregnancy and risk of GDM, and the association was partly mediated by pre-pregnancy BMI. This association exhibited as an age-dependent manner. Our study highlights even very low-level of thallium exposure could already pose a threat to human’s health.