Objective: To compare maternal glucose levels and neonatal outcome, achieved in women with gestational diabetes (GDM) receiving either regular insulin or insulin lispro, with those of a control group of non-diabetic pregnant women.
Study design: We enrolled 49 pregnant women with GDM, randomly allocated to the treatment with either insulin lispro (n=25) or regular insulin (n=24), and 50 pregnant women with normal GCT, matched for age, parity, pre-pregnancy weight and BMI, who formed the control group. All the women were caucasian, non-obese, with a singleton pregnancy and delivered term live born infants. Women of both groups were requested to perform a blood glucose profile (consisting of nine determinations: fasting/pre-prandial, 1 and 2h post-prandial) every week from the time of diagnosis to 38 weeks (study subgroups) or every 2 weeks from 28 to 38 weeks' gestation (control group).
Results: Overall pre-prandial blood glucose values in diabetic women were significantly higher than those of controls; at the 1h post-prandial time point, blood glucose values of GDM women receiving insulin lispro were similar to those of controls, whereas in the regular group they were significantly higher. Overall, both the lispro and regular insulin obtained optimal metabolic control at the 2h post-prandial time point, although near-normal blood glucose levels 2h after lunch could be observed only in the lispro group. There were no statistically significant differences between the groups in neonatal outcome and anthropometric characteristics; however, the rate of infants with a cranial-thoracic circumference (CC/CT) ratio between the 10th and the 25th percentile was significantly higher in the group treated with regular insulin in comparison to the lispro and control groups.
Conclusions: Fasting/pre-prandial and 1h post-prandial maternal blood glucose levels in non-diabetic pregnant women fell well below the currently accepted criteria of glycemic normality in diabetic pregnancies. In women with GDM, the use of insulin lispro enabled the attainment of near-normal glucose levels at the 1h post-prandial time point and was associated with normal anthropometric characteristics; the use of regular insulin was not able to blunt the 1h peak post-prandial response to a near-normal extent and resulted in infants with a tendency toward the disproportionate growth. Insulin lispro can be regarded as a valuable option for the treatment of gestational diabetes.