Daily Insulin Titration Results in Lower Fasting Glucose for Gestational Diabetes

Andrew P. McGovern, MD

New research suggest daily insulin titration could yield a lower fasting glucose and higher insulin dose use at week 36 for patients with gestational diabetes, ultimately resulting in less adverse pregnancy outcomes and a lower average birthweight.

A team, led by Andrew P. McGovern, MD, Royal Devon and Exeter Hospital, implemented a simple, patient-led, insulin dose titration algorithm that they hope improves fasting glycemic control in patients with gestational diabetes.

Gestational Diabetes

Gestational diabetes mellitus is glucose intolerance with onset or first recognition during pregnancy. This condition is estimated to complicate approximately 17% of pregnancies globally, with a large regional variation of 9-25% because of differences in obesity levels, ethnicity, screening strategies, and other factors.

Elevated fasting blood glucose in gestational diabetes could forecast high birthweight babies and adverse pregnancy outcomes, including macrosomia and babies that are large for gestational age, maternal and infant birth trauma, the greater need for obstetric intervention at delivery (caesarean section or assisted vaginal delivery), neonatal hypoglycemia, jaundice, and respiratory problems, and perinatal mortality. However, this condition can be difficult to treat.

“Longer-term, in utero exposure to hyperglycemia is associated with subsequent childhood obesity and insulin resistance,” the authors wrote. “Treatment of GDM with diet and lifestyle advice, and pharmacological therapy when required, reduces birthweight and GDM-associated complications.”

Insulin Increases

In the study, after initating basal insulin in women with gestational diabetes, the investigators recommended a daily 4 unit dose increase after every fasting glucose value at least 5.0 mmol/mol (90 mg/dl).

The new approach augmented a pre-existing intensive weekly specialist nursing input. The team used a before-and-after retrospective observational study design and examined insulin doses and glucose values at 36 weeks’ gestation and maternal and neonatal outcomes for 105 women completing pregnancy before the intervention and 93 women after the intervention. Both groups had similar baseline characteristics.

The participants who initiated insulin after implementation (n = 30 before, n = 43 after) achieved significantly higher doses at 36 weeks (53 vs. 36 units/day; 0.56 vs. 0.37 units/kg/day; P = 0.027).

The investigators also found those on insulin after implementation had a lower 36-week mean fasting glucose (4.6 vs. 5.1 mmol/L; 83 vs. 92 mg/dl]; P = 0.031).

Another result was that birthweight significantly decreased (birthweight Z-scores 0.34 vs. 0.92; P = 0.005), with no significant difference in macrosomia (after, 2% vs. before, 17%; P = 0.078) or caesarean sections (after, 33% vs. before, 47%; P = 0.116).

Safety

No participants experienced severe hypoglycemia and there were no outcome differences before intervention compared to after intervention in participants not treated with insulin.

“Patient-led daily insulin titration in gestational diabetes leads to higher insulin dose use lower fasting glucose and is associated with lower birthweight without causing significant hypoglycemia,” the authors wrote.

The study, “Patient-led rapid titration of basal insulin in gestational diabetes is associated with improved glycemic control and lower birthweight,” was published online in Diabetic Medicine.