Do You Need to Fast Before a Cholesterol Test?

Medically Reviewed by Arefa Cassoobhoy, MD, MPH on July 17, 2014
From the WebMD Archives

July 17, 2014 -- Do you really need to check your cholesterol levels on an empty stomach? New research suggests checking your cholesterol even if you’ve eaten gives you similar information.

Using data from the National Health and Nutrition Survey III (NHANES III), Bethany Doran, MD, of the NYU School of Medicine, and her colleagues found that higher LDL levels (the bad cholesterol) were linked to a higher risk of death. And it didn’t matter if the test was taken after fasting overnight or after eating.

"Based on the clinical guidelines, we've been advising patients to fast before a lipid panel," senior investigator Sripal Bangalore, MD, of the NYU School of Medicine, told heartwire. "But we might see the patient today, tell the patient to fast and come back another day for the test, and then I have to wait for the results. It's a lot of inconvenience, for the patient and also for us. We're able to start therapy only when we know their results. And we lose patients who simply drop out because they don't have the time to come back again."

For the study, published in the journal Circulation, researchers looked at 8,598 people who measured their cholesterol levels in the NHANES III study and were followed for about 14 years.

Increasing LDL levels were linked to an increasing risk of death for any reason in those who were fasting or not before their cholesterol test. This same group also had a greater risk of death from heart and blood vessel disease.

"All the guidelines' recommendations are based more on expert opinion rather than evidence," Bangalore says. "But we're really looking at the patient when he or she is on their best behavior. We tell them, 'Don't eat your French fries for 8 hours, and then we'll take your lipid panel.' But that's not what the body is exposed to the majority of the time. What the body is exposed to the majority of the day is the non-fasting state, so this actually makes more sense. I always say fasting is a bit like cramming for an exam. You're staying up late the night before, trying to cram and pass the test that way."

By not insisting you have to be fasting for the cholesterol test, the study suggests you’ll still get the health information you need, and it will make it easier for you to get the test done.

Bangalore is on the advisory board for Pfizer. Disclosures for the coauthors are listed in the paper.