Response to Comment on Kovatchev and Cobelli. Glucose Variability: Timing, Risk Analysis, and Relationship to Hypoglycemia in Diabetes. Diabetes Care 2016;39:502-510

Clinical study of pregnancy-associated fulminant type 1 diabetes

BACKGROUND

Studies reported that fulminant type 1 diabetes (fT1DM) can occurred during pregnancy or within 2 weeks after delivery, and was defined as pregnancy-associated fulminant type 1 diabetes (PF). In PF patients, plasma glucose (PG) levels have an abrupt rise while glycated hemoglobin (HbA_1C) levels are not markedly elevated, resulting in a sharply increased PG/HbA_1C ratio.

METHODS

We studied 30 PF patients, 21 non-pregnant fulminant type 1 diabetes (NPF) patients, and 26 female patients of child-bearing age (13-49 years) with diabetic ketoacidosis (DKA), all from China. We analyzed the PG/HbA_1C ratio among these groups, with the goal of finding a method for predicting PF. The clinical and biochemical characteristics of the PF and NPF patients were analyzed and compared with the characteristics of the DKA patients. In order to detect PF in DKA patients, receiver-operating characteristic curves analysis was used to identify the cut-off points of the PG/HbA_1C ratio.

RESULTS

When we compared the clinical characteristics of these three groups, we found that the onset of hyperglycemic symptoms, arterial PH value, serum potassium, PG, HbA_1C, fasting and postprandial serum C-peptide concentration, glutamic acid decarboxylase (GAD) antibodies positivity were all significantly different (P < 0.001). The PG/HbA_1C ratio was significantly higher in PF and NPF patients (5.29 ± 1.39 and 6.38 ± 2.62) than in DKA patients (1.93 ± 0.55; P < 0.001). Receiver-operating characteristic (ROC) curves analyses showed that PG/HbA_1C ratio at a cut-off value of 3.3 resulted in the highest Youden index, with corresponding sensitivity of 93 and 100% specificity for identifying PF from DKA.

CONCLUSIONS

PF patients showed a more severe acidosis, with maternal and fetal mortality rates being high. PG/HbA_1C ratio with a threshold of ≥3.3 can be used as a cut-off point in predicting PF from DKA in China. Elevated PG/HbA_1C ratio at the time of diagnosis is predictive for more severe insulin secretion dysfunction and poor prognosis.