Predictive value of early pregnancy fasting blood glucose for development of gestational diabetes mellitus

Abstract

Objective To evaluate the value of early pregnancy fasting plasma glucose(FPG) to predict gestational diabetes mellitus(GDM) in pregnant women with or without GDM risk factors. Methods From June 2013 to September 2014, 3 223 singleton healthy pregnant women in Peking University First Hospital were recruited and their demographic/medical information were collected using. Based on age, pre-pregnancy body mass index (BMI) and family history of diabetes, participants were grouped into GDM risk factors positive group (n=1 341) and GDM risk factors negative group (n=1 892). T-test and χ2 test were used for between-group comparison. Receiver operating characteristic (ROC) curve was used to evaluate the prediction of early pregnancy FPG for GDM. Results (1) Pregnant women with GDM risk factors had significantly higher FPG levels in early pregnancy compared to those without GDM risk factors ((5.1±0.4)vs (5.0±0.4) mmol/L, t=6.44, P<0.001).(2)Compared to women with FPG<4.75 mmol/L and those without GDM risk factors, women with GDM risk factors and with 4.75≤FPG<5.00 mmol/L, 5.00≤FPG<5.25 mmol/L and FPG≥5.25 mmol/L had a significant increased risk of developing GDM, the OR values were 1.84(95% CI 1.26-2.70),2.46 (95%CI 1.71-3.52) and 6.99 (95%CI 5.01-9.77) respectively; while in GDM risk factors negative group, only those with FPG≥5.25 mmol/L had a significant increased risk of developing GDM, and the OR value was 2.55 (95%CI 1.80-3.60). There was approximately a 1.6-fold increase (95%CI 1.45-1.98) in the risk of developing GDM for each 0.5 mmol/L increment in FPG in women without GDM risk factors, while a 2.33-flod increase (95% CI 1.96- 2.61) in women with GDM risk factors. (3) Based on the ROC analysis, the area under the curve of early pregnancy FPG in predicting GDM for women with and without GDM risk factors was 0.694(95%CI 0.661-0.732) and 0.620 (95%CI 0.580-0.662),respectively. The optimal cut off value was 5.17 mmol/L and 5.09 mmol/L respectively. Conclusions Early pregnancy FPG has greater effect on predicting GDM in women with GDM risk factors. The optimal cut off values of FPG in predicting GDM are different between women with and without GDM risk factors. Key words: Diabetes mellitus, gestational; Fasting blood glucose; Early pregnancy