Assessment of predictors of insulin therapy in patients with gestational diabetes diagnosed according to the IADPSG criteria

Aims and introduction: It is helpful for both diabetologists and obstetricians to identify patients with gestational diabetes who require insulin therapy for glycemic control during pregnancy. The aim of the present study was to assess potential predictors of insulin requirement in patients with gestational diabetes. Materials and methods: One hundred thirteen patients with gestational diabetes [mean age 34.2 ± 4.5 years; pre-gestational body mass index (BMI), 23.6 ± 6.0 kg/m2] were included in this study. The associations between insulin requirement and the following factors were analyzed: clinical maternal characteristics, number of abnormal oral glucose tolerance test (OGTT) values, gestational age at diagnosis, plasma glucose levels measured during the OGTT, glycated hemoglobin (HbA1c) and glycated albumin levels, and serum C-peptide level before breakfast and 1 and 2 h after breakfast. Results: Thirty-six patients (32 %) required insulin during pregnancy (“insulin group”); the remaining patients were treated with nutrition therapy (“nutrition group”). The insulin group had a higher pre-gestational BMI, higher fasting glucose level, higher area under the curve (AUC) for serum C-peptide level, higher HbA1c level, and a younger gestational age at diagnosis than the nutrition group (p < 0.05, all). Logistic regression analysis showed that the pre-gestational BMI, AUC for serum C-peptide level, and the HbA1c level were independent predictors for the insulin group (p < 0.05, all). Conclusions: The results suggest that a high insulin resistance and HbA1c level may be associated with insulin requirement in patients with gestational diabetes. © 2016, The Japan Diabetes Society.