Fasting is no longer required prior to blood draws for lipid tests, according to a consensus statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine, published online in the European Heart Journal.
Standard practice in most countries today calls for patients to fast for at least 8 hours prior to having blood drawn. But in Denmark, non-fasting lipid testing has been used since 2009, while guidelines from the National Institute for Health and Care Excellence in the United Kingdom also support non-fasting lipid testing in the primary prevention setting.
In 2013, the American College of Cardiology and the American Heart Association released guidelines noting that non-fasting lipid tests can be used for assessing cardiovascular risk, but still recommended a fasting lipid panel prior to statin initiation.
The European panels recommended that non-fasting blood samples be “routinely used for the assessment of plasma lipid profiles, with laboratory reports flagging abnormal values on the basis of desirable concentration cut-points. Non-fasting and fasting measurements should be complementary but not mutually exclusive.”
There are several advantages to non-fasting testing, the panel noted: Laboratories won’t be overwhelmed with people in the morning; patients can receive testing during a physician visit; and patients are likely to be more compliant with testing. Requiring fasting is also difficult for those with diabetes and for children.
In releasing the recommendations, the panel cited several large studies that confirmed only modest differences in plasma lipids and lipoproteins when serum or blood lipids were measured in the postprandial versus fasting state. In addition, the panel noted, non-fasting testing does not appear to have any effect on cardiovascular risk assessment.
The panel wrote that non-fasting testing is generally appropriate in patients undergoing an initial lipid profile or cardiovascular risk assessment; those admitted with acute coronary syndrome; and for children, the elderly, and patients with diabetes. It is also appropriate if the patient prefers it.
The panel did highlight certain situations in which a fasting lipid profile may be preferred:
- Non-fasting triglycerides 0.5 mmol/L (440 mg/dL)
- Known hypertriglyceridemia followed in lipid clinic
- Recovering from hypertriglyceridemic pancreatitis
- Starting medications that cause severe hypertriglyceridemia
- Require additional laboratory tests that entail fasting or morning samples, such as fasting glucose, and therapeutic drug monitoring
The consensus statement also highlighted abnormal plasma lipid, lipoprotein, and apolipoprotein concentration values in non-fasting samples that should be flagged in laboratory reports based on desirable concentration cut-points. These include a total cholesterol ≥190 mg/dL, a low-density lipoprotein cholesterol ≥115 mg/dL, and an high-density lipoprotein cholesterol ≤40 mg/dL.
Finally, the panel recommended several strategies for implementing a non-fasting protocol, including beginning non-fasting testing and reporting at the university hospital and lab level; eliciting support from major medical societies; and developing a media campaign to reach the public.