Clinical values of plasma CMPF level in diagnosis of gestational diabetes mellitus

Objective To investigate clinical values of plasma 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) level in diagnosis of gestational diabetes mellitus (GDM). Methods A total of 60 pregnant women who admitted into Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University from January 2016 to June 2017 were selected as the study subjects. They were divided into GDM group (n=40) and control group (n=20) according to whether they were combined with GDM or not. All pregnant women were tested for biochemical markers during 13 to 18 gestational weeks. And 75 g oral glucose tolerance test (OGTT) was performed during 24 to 28 gestational weeks. At the same time, ultra-high performance liquid chromatography-triple quadrupole mass spectrometry was used to detect plasma CMPF level. The body mass index (BMI) at 28 gestational weeks and at neonatal term, high-density lipoprotein (HDL), low-density lipoprotein (LDL), total protein, albumin, urea, and uric acid were compared between two groups by independent-samples t test. Gestational age, gravidity, parity, plasma CMPF level, BMI at 18 gestational weeks, hemoglobin A1c (HbA1c), glycated albumin (GA), creatinine and other indicators between two groups were compared by Mann-Whitney U test. Multiple unconditional logistic regression analysis was used to analyze the influencing factors of GDM in pregnant women. The receiver operating characteristics (ROC) curves for plasma CMPF level and BMI at 18, 28 gestational weeks, and the combination these 3 factors, and the combination of OGTT 0, 1, 2 h blood glucose concentrations in diagnosis of GDM were built respectively, and the area under ROC curve (ROC-AUC) of them were calculated. The procedures followed in this study were in accordance with the ethical standards established by the Human Subjects Trial Committee of the Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University, and this study was approved by this committee (approval number: 2017-012). Informed consent was obtained and signed with each subject. Results ① There was no significant difference in the general clinical data such as gestational age, gravidity and parity between two groups (P>0.05). ②The plasma CMPF level of GDM group was 522.0 ng/mL (326.9-989.3 ng/mL), which was significantly higher than that of control group 280.2 ng/mL (177.8-466.6 ng/mL). The difference between two groups was statistically significant (U=576.000, P=0.006). ③BMI at 18, 28 gestational weeks and at neonatal term, and HbA1c in GDM group were 24.6 kg/m2 (22.0-25.9 kg/m2), (26.1±2.8) kg/m2, (27.6±2.9) kg/m2, and 5.4% (5.3%-5.6%), respectively, which were significantly higher than those in control group 22.8 kg/m2 (20.1-23.6 kg/m2), (24.5±2.6) kg/m2, (25.5±2.6) kg/m2, 5.2% (5.0%-5.3%), and all the differences were statistically significant (U=568.000, P=0.002; t=2.150, P=0.001; t=1.180, P=0.036; U=226.000, P<0.001). The GA in GDM group was 11.6% (10.8%-12.8%), which was significantly lower than that in control group 12.6% (12.2%-13.2%), and the difference was also statistically significant (U=248.000, P=0.017). ④The results of multiple unconditional logistic regression analysis of the influencing factors of GDM in pregnant women showed that plasma CMPF levels and BMI at 18, 28 gestational weeks were independent influencing factors of GDM in pregnant women (OR=1.003, 95%CI: 1.000-1.005, P=0.023; OR=4.393, 95%CI: 1.675-11.525, P=0.003; OR=0.322, 95%CI: 0.130-0.798, P=0.014). ⑤The results of ROC curve analysis showed that the ROC-AUC of plasma CMPF level, BMI at 18, 28 gestational weeks in diagnosis of GDM were 0.703 (95%CI: 0.554-0.852, P=0.014), 0.741 (95%CI: 0.605-0.876, P=0.004), and 0.672 (95%CI: 0.523-0.821, P=0.039), respectively. The ROC-AUC of plasma CMPF level combined with BMI at 18 and 28 gestational weeks in diagnosis of GDM was 0.847 (95%CI: 0.741-0.952, P<0.001), and the ROC-AUC of combination of OGTT 0, 1, 2 h blood glucose concentrations in diagnosis of GDM was 0.983 (95%CI: 0.957-1.000, P<0.001), and there was no statistically significant difference between them (U=9.000, P=0.100). According to the maximum principle of Youden index, the best cut-off values of plasma CMPF level and BMI at 18, 28 gestational weeks for diagnosis of GDM were 397.2 ng/mL, 23.9 kg/m2, 26.2 kg/m2, respectively, and the sensitivities of them in diagnosis of GDM were 65.6%, 59.4% and 53.1%, respectively, and the specificities were 75.0%, 90.0% and 80.0%, respectively. Conclusion The plasma CMPF level at 24 to 28 gestational weeks combined with BMI at 18 and 28 gestational weeks has a good clinical diagnostic value for GDM. Key words: 3-Carboxy-4-methyl-5-propyl-2-furanpropanoic acid; Diabetes, gestational; Body mass index; Diagnosis; Logistic models; ROC curve; Pregnant women