Association Between Urine Arsenic Levels During Early Pregnancy And Gestational Diabetes Mellitus

Objective: We detected the levels of urine arsenic(As)of pregnant women during early pregnancy,and explored the relation between arsenic exposure and gestational diabetes mellitus(GDM).Methods: Pregnant women from Tongji Maternal and Child Health Cohort study who had donated urinary samples at 11-17 weeks of gestation during july 2014 to july 2016 were involved.Questionnaire was used to obtain the information on sociodemographic,lifestyle style during early pregnancy at enrollment.The height and weight of pregnant women was measured by the investigators.Urine samples of pregnant women were collected during early pregnancy.At 24-28 weeks of gestation,the pregnant women underwent oral glucose tolerance test.After delivery,information of fetal sex was obtained from hospital records.Urine As concentrations were examined by Inductively coupled plasma mass spectrometry(ICP-MS).To adjust variations in urine dilution,we examined the urinary creatinine concentration of the same spot urine specimens using a Mindray BS-200 creatinine kit.After adjusted by urinary creatinine concentration,the women were categorized into three groups according to tertile of the creatinine-corrected As(CC-As)concentrations.The association between urine CC-As levels during early pregnancy and GDM was examined using logistic regression model after adjustment for confounders.Results: During early pregnancy,a total of 2282 pregnant women provided urine samples.After excluded those with multiple pregnancies,abortion or stillbirth in the early pregnancy,suffered T2 DM before pregnancy or without diagnostic information of GDM,and lost to follow-up at birth,1930 pregnant women with live,singleton births were remained in the final analysis.The mean age of these women was 28.4 ± 3.4 years,and the mean pre-pregnancy body mass index(BMI)was 21.0 ± 2.8kg/m2.224(11.6%)of the women were diagnosed with GDM.The median(IQR)of the As,CC-As concentrations in all participants were 29.84(18.89-46.93)ug/L,38.77ug/g(29.16-54.50)ug/g.The CCAs concentrations were significantly higher in women with GDM than those without GDM(median value:44.02ug/g vs 38.35ug/g,P =0.005).Compared with women in the lowest tertile,women in the highest tertile of CC-As had increased risk OR 1.70(95%CI:1.18,2.45)for GDM after adjustment for confounders(P for trend =0.005).Stratified analysis by maternal age,prepregnancy BMI,gravidity showed that the risk were more pronounced in women in elder age,were overweight or obese before gravidity and with multigravida,the adjusted OR = 2.28(95%CI:1.30,4.00),1.99(95%CI:1.26,3.13),and 2.11(95%CI:1.25,3.56)respectively.Conclusions: Our study showed a significantly positive relation between higher urine As levels and risk of GDM,especially in pregnant women in elder age,were overweight or obese before gravidity and multigravida.