PracticeUpdate: Diabetes

ADA 2018 25

Intensive Glycemic Control During Pregnancy By Jason Sloane MD W e’ve known for some time that achieving optimal glycemic control during pregnancy is vital for the safety of the mother and the fetus. Until recently, the only way to mon- itor glycemic control during pregnancy was with capillary blood glucose meas- urement and HbA1c tests. In the past few years, the technology behind con- tinuous glucose monitoring (CGM) has improved significantly, and now we as clinicians have another reliable method of measuring glycemic control over time. The results of the CONCEPTT trial were presented by Dr HelenMurphy at the ADA meeting. Her groupwanted to test the effi- cacy of using real-time CGM in improving neonatal outcomes and maternal HbA1c levels. They recruited 110 women plan- ning pregnancy and 215 women who were already pregnant and using inten- sive insulin therapy to be randomized to normal capillary finger-stick glucose mon- itoring or CGM. The trial results showed that, at 34 weeks gestation, there was a decrease in HbA1c in the CGM group, and this effect was consistent across all centers involved. The time in range for the CGMgroupwas also better, although there was no improvement in hypoglycemia. Regarding neonatal outcomes, large for gestational agewas 53% in theCGMgroup and 69% in the control group. The number of infants requiring dextrose immediately after delivery was significantly higher in the non-CGM control group. There was also mention of a subsequent pilot study using a closed-loop insulin pump system in 16 pregnant women with diabetes compared with usual care in 16 other pregnant women with diabetes. The preliminary results were promising, with significantly less hypoglycemia in the closed-loop group and similar mean glucose levels between the groups. The take-home message from this pres- entation was that glycemic control during pregnancy is very important – so clini- cians should be aware of tools such as CGM and closed-loop insulin pumps, which can be used to improve that con- trol and improve pregnancy-related outcomes. www.practiceupdate.com/c/70224

" It is likely that much of what is considered gestational diabetes is actually diabetes or lesser degrees of hyperglycemia that preceded pregnancy but was not detected. "

prevalence differed significantly by treat- ment group. “Glucose tolerance can change during preg- nancy in ways we didn’t expect,” said Dr. Knowler. “To better understand the devel- opment of gestational diabetes, we need to test for it at different gestational ages, and preferably prior to conception. It is likely that much of what is considered gestational dia- betes is actually diabetes or lesser degrees of hyperglycemia that preceded pregnancy but was not detected.” He noted that the current study lacks detailed data on how the pregnant women were managed outside the research set- ting and how this management might have affected blood glucose concentrations. Reference 1. The LIFE-Moms Research Group. Design of Lifestyle Intervention Trials to Prevent Excessive Gestational Weight Gain in Women with Overweight or Obesity. Obesity (Silver Spring, Md) 2016;24(2):305-313. www.practiceupdate.com/c/70040

“Contrary to expectations, glucose toler- ance improved on average between these two times, and the number of women meet- ing test criteria for gestational diabetes decreased,” said Dr. Knowler. “The likely explanation was that despite decreasing insulin sensitivity during preg- nancy, most of the women increased insulin secretion sufficiently to compen- sate, thereby preventing development of gestational diabetes,” he noted. Specifically, the researchers found that plasma or serum glucose declined from early to later tests by a mean of 2.5 mg/dL (fasting), 10.9 mg/dL (1 hour), and 9.3 mg/dL (2 hour), each P < .0001. The prevalence of GDM by IADPSG criteria declined from 20% at < 16 weeks gestation to 15% at 24–31 weeks ( P = .04). Only 9% of women without GDM at < 16 weeks gestation developed it by 24–31 weeks, whereas 65% of those meeting GDM criteria at < 16 weeks gesta- tion did not meet GDM criteria at follow-up. None of the changes in glucose or GDM

VOL. 2 • NO. 3 • 2018