AT AACE 2015

NASHVILLE, TENN. (FRONTLINE MEDICAL NEWS) – When ordering a fasting blood test for patients with diabetes, it’s prudent to have them cut back on their insulin and oral hypoglycemic agents to avoid hypoglycemia.

Unless they take such protective actions, an estimated half or more will be hypoglycemic by the time their blood is drawn, according to a survey from Michigan State University.

Of the 74 study participants – mostly people with type 2 diabetes – who have enrolled so far in the ongoing project, 37 (50%) reported overnight fasting for lipid profiles or other tests in the previous year. Just three cut back on their medications, either on their own or on the advice of their doctors. Just over half the subjects were women, about three-quarters had type 2 diabetes, and the average age in the study was 53 years.

Twenty-three of the 37 patients (62%) reported at least one hypoglycemic event while fasting, with plasma glucose falling below 70 mg/dL. Some had up to seven events. Most told their doctors what had happened, but steps weren’t often taken to prevent future events.

“These interim results vividly confirm the occurrence of” fasting hypoglycemia “in clinical practice, and indicate a significant prevalence” among patients with diabetes. “This study serves as a means of increasing awareness about” the problem, “which clinicians appear to overlook,” concluded the investigators, led by Dr. Saleh Aldasouqi, associate professor of medicine and chief of endocrinology at Michigan State, East Lansing.

Dr. Aldasouqi first noticed the problem several years ago when practicing in Cape Girardeau, Mo. He fielded several calls there from nervous lab technicians reporting hypoglycemia in patients with diabetes who had fasted overnight. “We looked at the world literature on this at the time and found zero,” he said, except for a case report of a woman who collapsed and died while waiting for a lipid draw after fasting the night before. Her blood glucose was zero.

That report prompted Dr. Aldasouqi and his colleagues in Cape Girardeau to study the issue. They found that hypoglycemia ranged from 69-30 mg/dL among 35 patients with diabetes who recalled fasting or possibly fasting for a blood test. None recalled adjusting their medications (Diabetes Care 2011;34:e52).

Dr. Aldasouqi dubbed the problem fasting-evoked en-route hypoglycemia in diabetes (FEEHD): “en-route” to invoke the possibility that patients with diabetes might crash if their blood sugar drops too low while driving in for a blood draw, he said at the annual meeting of the American Association of Clinical Endocrinologists.

The next step in Cape Girardeau was a prevention program to monitor blood glucose and adjust medications for patients with diabetes who were fasting for a test. It reduced the incidence of hypoglycemic events by 68%, with an even greater drop in the incidence of severe hypoglycemia below 50 mg/dL (Postgrad. Med. 2013;125:136-43).

“We’ve been trying to build a case” that FEEHD really is a problem, but there’s been some skepticism because “we are trying to change a deeply rooted tradition” and the notion that diabetics can fast just like anyone else. Even so, “people are coming around now that we have data,” Dr. Aldasouqi said. Currently at Michigan State, “my group is not ordering fasting” for lipid tests, although it remains routine in other clinics there. They opted for that approach, instead of reducing diabetes medications during fasts, because of the growing evidence that patients – whether they have diabetes or not – really don’t need to fast for lipid panels, he said (Circulation 2015;131:e471).

There was no external funding for the project. Dr. Aldasouqi is a speaker or adviser for Janssen, Sanofi, and Takeda.