Diet, medical therapy beneficial targets for treatment of gestational diabetes

EASD 47th Annual Meeting

LISBON — Adopting a low-glycemic-index diet and using supplementary oral hypoglycemic agents such as glibenclamide or metformin represent two effective and economical methods to reduce the likelihood of adverse outcomes associated with gestational diabetes, a speaker said here.

Such outcomes include increased rates of cesarean delivery, macrosomia, neonatal hypoglycemia and fetal hyperinsulinism.

“The evidence we now have supports the fact that this is a disease worth treatment; effective treatments are available, and the effective treatments are cost-effective,” Robert B. Fraser, MD, of the gynecology academic department of reproductive and developmental medicine at University of Sheffield, U.K., said here.

In one of the largest studies of gestational diabetes to date, researchers for the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study found that the incidence of adverse outcomes rose in a continuum related to increases of maternal fasting glucose level and 1- and 2-hour levels after a 75-g oral glucose load. In addition, a meta-analysis of two recent studies — the Australian Carbohydrate Intolerance Study in Pregnant Women (ACHOIS; 2005) and the Maternal-Fetal Medicine Units Network Trial (2009) — showed significant reductions in preeclampsia, birth weight, the proportion of large-for-gestational-age infants and shoulder dystocia with treatment for gestational diabetes. Treatment was associated with no change in cesarean delivery rates or neonatal hypoglycemia.

“Approaches to treatment should include diet and supplementary insulin or oral hypoglycemic agents if diet alone fails to achieve acceptable glycemic control,” Fraser said in a press release. He cited data from a randomized trial by Moses et al published in Diabetes Care in 2009 that compared a low-glycemic-index diet with a conventional high-fiber diet; results showed that the low-glycemic-index diet halved the need for insulin in women with gestational diabetes. In a systematic review and meta-analysis of the oral hypoglycemic agents glibenclamide and metformin vs. insulin, researchers found no difference between the diabetes agents and insulin in fasting glycemic control, postprandial glycemic control, cesarean section rates, neonatal birthweight, macrosomia or neonatal hypoglycemia. The results were published recently in the American Journal of Obstetrics and Gynecology.

“Recent studies performed over the last 10 to 15 years, looking at whether oral hypoglycemic drugs, which are prescribed widely for type 2 diabetes, can be used safely in pregnancy. After reviewing recent trials, [oral hypoglycemic agents] appear to be at least equivalent to insulin, in terms of the short-term outcomes of pregnancy. These drugs might represent a therapeutic [approach] to women who may oppose injections [with insulin],” Fraser said at the press conference.

The cost effectiveness of screening and treating gestational diabetes was addressed recently in a paper by Round et al published in Diabetologia. Based on the two treatment-randomized controlled trials, these trials assessed cost-benefit on the basis of the likelihood of a diagnosis of gestational diabetes in the individual. Where the risk was less than 1%, no screening or treatment strategy was cost effective. Where the risk was 1% to 4.2%, a two-stage screening program with fasting plasma glucose followed by OGTT was most likely to be cost effective. Finally, with an individual risk greater than 4.2%, universal glucose tolerance testing was cost effective.

“This suggests that for many women requiring supplementary hypoglycemic therapy in addition to diet, oral hypoglycemic agents are a cheap and effective alternative,” Fraser said in the press release. “There is evidence from the MiG trial that metformin might be the drug of choice for those who are obese in association with their diagnosis of gestational diabetes.”

Gestational diabetes treatment practices vary across the world, and many units still prefer insulin as the hypoglycemic drug of first choice, according to Fraser. He suggested that should the cost-effective treatments of diet and cheap oral agents be used, there could be substantial savings across the health system.

For more information:

• Fraser RB. Controversies in gestational diabetes. Should we treat mild gestational diabetes? Presented at: The European Association for the Study of Diabetes 47th Annual Meeting; Sept. 12-16, 2011; Lisbon.

Disclosure: Dr. Fraser reports no relevant financial disclosures.

Based on the new [proposed International Association of the Diabetes and Pregnancy Study Groups] criteria, with which a larger number of women would be diagnosed with gestational diabetes, it is very important to focus on how we can be able to treat the patient as cheap and effective as possible.

– Elisabeth R. Mathiesen, MD
Head of Diabetes Treatment
Copenhagen Center for Pregnant Women with Diabetes
Denmark

Disclosure: Dr. Mathiesen reports no relevant financial disclosures.

A low-glycemic-index diet is a powerful tool for the treatment of diabetes in pregnancy. The body of evidence for oral hypoglycemic agents to treat gestational diabetes is growing. However, postprandial hyperglycemia is our villain in gestational diabetes. We should be sure that our chosen therapeutic regimen will prevent post-prandial excursions in blood glucose.

– Kristin Castorino, DO

Internist and Clinical Research Physician
Sansum Diabetes Research Institute

Disclosure: Dr. Castorino reports no relevant financial disclosures.

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