Experts say there are things you can do before these tests, including adjusting medication and eating a small breakfast.
Skipping breakfast — or even delaying it a few hours — for the sake of a “fasted blood draw” isn’t a big deal for most people.
For people with diabetes, however, suddenly skipping breakfast can lead to dangerous fluctuations in their blood sugar levels if they aren’t taught how to properly adjust their medication regimen.
While countries such as Canada and Europe no longer require fasting for cholesterol tests, the United States still follows this outdated guideline, according to Dr. Saleh Aldasouqi, an endocrinologist in the College of Human Medicine at Michigan State University and lead author of the study recently published in the International Journal of Endocrinology
Fasting is considered a critical part of obtaining accurate test results in the many healthcare systems when measuring for certain cholesterol, liver, kidney, and glucose levels.
Aldasouqi told Healthline this approach is based on standards established in the 1970s, and it’s unnecessary, especially for people with diabetes.
“Hypoglycemia is an overlooked problem that we see from time to time in patients with diabetes who show up for lab tests after skipping breakfast,” explained Aldasouqi.
“Patients continue taking their diabetes medication but don’t eat anything, resulting in low blood sugar levels that cause them to have a hypoglycemic event while driving to or from the lab, putting themselves and others at risk,” he said.
The issue has become common enough to earn its own acronym: FEEHD, which stands for “fasting-evoked en route hypoglycemia in diabetes.”
Hypoglycemia, more commonly referred to as “low blood sugar,” usually begins with symptoms of lightheadedness, shaking, sweating, and feeling weak.
It can eventually result in losing consciousness, seizure, and death if not treated in time.
Many diabetes medications used in treating type 2 diabetes lower blood sugar levels by a combination of increasing the body’s insulin secretion and increasing its overall sensitivity to insulin — both of which could result in low blood sugar if the patient skips a meal.
These medication dosages are prescribed based on the expectation the patient is consuming their usual calorie and carbohydrate intake.
By suddenly asking a patient with diabetes to skip breakfast without instructing them how to safely adjust their medications can be dangerous.
Hypoglycemia while driving to the hospital for fasted blood work can be fatal for both the driver and others on the road.