ADA 2014 Guidelines Offer Choices for GDM Screening

Miriam E. Tucker

December 19, 2013

In a policy shift, the American Diabetes Association (ADA) now advises that either the 1- or 2-step method is acceptable for gestational diabetes mellitus (GDM) screening.

The new recommendation was published online December 19 in Standards of Medical Care in Diabetes — 2014, part of the ADA's annually revised clinical-practice guidelines supplement to the January issue of Diabetes Care.

Previously, the ADA had supported the 1-step GDM screening devised in 2010 by the International Association of Diabetes and Pregnancy Study Groups (IADPSG). Now, the ADA says that there is not enough evidence to recommend that method over the 2-step screen recommended by the National Institutes of Health (NIH) in March 2013.

Also new this year is a section on medical nutrition therapy, initially published in Diabetes Care in October, and an expanded section on neuropathy, along with an ongoing overall emphasis on recommendations that are both evidence-based and patient-centered.

"In general, what we've tried to do this year, as every year for the past few years, is line up our recommendations with solid evidence... We've been trying as much as possible to replace expert-opinion recommendations with similar recommendations that are based on high-level evidence. That's a general trend we've continued this year," Richard Grant, MD, MPH, a research scientist at the Kaiser Permanente Division of Research, Oakland, California, and chair of the ADA Professional Practice Committee, told Medscape Medical News.

This wasn't a year for major shifts in perspective on diabetes management, noted Dr. Grant.

"Other than the pulling back from telling people which type of GDM screening to use, there's nothing dramatic that changed this year. There weren't really any huge studies that changed the direction of care... I see this year's standards as sort of an incremental tightening up of the guidelines, trying to rely on evidence and recognizing that 1 size doesn't fit all patients."

One-Step, Two-Step

The 2-step GDM diagnostic approach endorsed by the NIH in March also reflects the position of the American Congress of Obstetricians and Gynecologists (ACOG) and is currently the common practice in the United States. It involves a nonfasted 1-hour, 50-g glucose challenge followed by a diagnostic fasted 3-hour, 100-g oral glucose tolerance test (OGTT) only for those women who exceed a designated glucose cutoff.

The 1-step approach, endorsed by the IADPSG and also proposed by the World Health Organization, is a more common practice in Europe. The approach involves a single fasted 75-g 2-hour OGTT.

The 2-step method has the advantage of convenience, because women don't have to fast. However, the 1-step method identifies more GDM cases. The IADPSG believes identifying more cases is important in light of the landmark Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study, which found an increased risk for adverse pregnancy and neonatal outcomes even at mild levels of maternal hyperglycemia.

However, Dr. Grant noted, HAPO was an observational trial, and there is no evidence from randomized clinical trials showing that either screening method improves outcomes. Interestingly, both the IADPSG and NIH panels arrived at their differing recommendations by examining identical data.

"We ultimately decided that it's not really up to us to referee which of these 2 expert consensus panels is more right. It's more important to say these are the facts, and these are the kinds of value judgments that go into each consensus. We really need to do more research to determine which of the 2 has better outcomes," he told Medscape Medical News.

Patient-Centered Focus

A newly expanded section on diabetic neuropathy goes into more detail about the various treatments and their limitations. The section encourages physicians to be more persistent in urging patients to stay on medications long enough to give them a chance to work and using an individualized "trial-and-error" approach with different drugs and drug combinations.

"Neuropathy is a difficult condition to treat, and the meds we have aren't that good... This is an area that really requires communication between the care team and the patient," Dr. Grant told Medscape Medical News.

The new medical nutrition-therapy section also emphasizes an individualized approach, focusing on overall eating patterns and patient preference rather than any particular dietary prescription. In fact, it doesn't even use the word "diet," lead author Alison Evert, MS, RD, CDE, coordinator of diabetes education programs at the University of Washington Medical Center, Seattle, told Medscape Medical News back in October.

"Throughout the document, we refer to 'eating plans' or 'eating patterns' rather than 'diet.' We want to work with patients and help them achieve individual health goals. A variety of eating patterns can help, and people are more likely to follow an eating plan that speaks to them," Ms. Evert said.

ADA Led the Way

In the 2013 ADA standards, the big change from 2012 was an easing of the systolic blood-pressure target for people with diabetes from below 130 mm Hg to below 140 mm Hg, on the basis of evidence that there is not a great deal of additional value but there is an increase in risk in pushing systolic pressure much lower than 140 mm Hg, Dr. Grant told Medscape Medical News last year.

Just this week, the same recommendation for people with diabetes was included in the long-awaited Eighth Joint National Committee (JNC 8) guidelines on the management of adult hypertension.

Dr. Grant has reported no relevant financial relationships.

Diabetes Care. Published online December 19, 2013. Available here


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.