Comparing results from more than 300,000 individuals, international experts recommend using non-fasting blood screening for most cholesterol and triglyceride tests
Every clinical laboratory offering cholesterol testing across the globe must deal with a common issue: because patients are told to fast overnight before giving a blood specimen, patient service centers (PSCs) and blood collection centers are overcrowded when they first open their doors in the morning. That’s because hungry patients want their sample collected so they then go eat something as soon as possible.
It has long been recognized that the overnight fasting requirement for collecting blood samples used in cholesterol testing is unpleasant for patients. It also adds cost to the healthcare system because labs must staff an adequate number of phlebotomists in their PSCs to handle the predictable early morning rush of hungry patients wanting to be done with this task. Meanwhile, in the afternoons, patient traffic in the same PSCs can dwindle to near nothing, leaving phlebotomists in those PSCs with little to do.
Non-Fasting Clinical Laboratory Blood Tests Have Advantages
What has the potential to change this situation for the better—both for patients and for medical laboratories—are newly-published studies involving sizeable numbers of patients that indicate the results of cholesterol testing differ little, whether or not the patient had fasted prior to providing a blood sample. Medical laboratory professionals in Europe are ahead of their North American colleagues in this regard.
Experts from the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently argued the case for non-fasting blood samples for cholesterol and triglyceride screenings in the European Heart Journal.
After analyzing the test results of more than 300,000 samples from Denmark, the United States, and Canada, researchers noted, “There are advantages to using non-fasting samples rather than fasting samples for measuring the lipid profile.” This is good news to patients sitting in waiting rooms each morning with empty stomachs and the clinical pathology labs dealing with a deluge of samples at the start of the day.
Non-Fasting Samples Ease the Burden on Patients as well as Clinical Labs
One of the most important benefits listed in the research is the positive impact on patient compliance found in non-fasting regions. Non-fasting sampling reduces the burden on children, diabetics, and elderly patients required to submit blood samples for cholesterol testing. That’s because the research suggests that, rather than requiring patients to spend a night hungry, patients can submit non-fasting samples at their convenience at any time of the day.
These findings will be familiar to regular readers of Dark Daily. We reported on similar findings from a 2012 Canadian study. Researchers looked at 200,000 patient results and they concluded that that a non-fasting lipid test would be a reasonable alternative for most people. (See Dark Daily, “Fasting for Cholesterol Testing May Be Unnecessary: That Could Ease the Morning Rush of Patients at Clinical Laboratories,” December 26, 2012.)
What may impede acceptance of the use of non-fasting blood samples for cholesterol testing is the need to educate physicians about the results of these research studies. It may also require statements from professional medical societies and organizations that it is acceptable for physicians to use cholesterol test results derived from non-fasting blood specimens.
For this reason, it would be beneficial for the nation’s clinical laboratory and pathology societies, colleges, and associations to work with the media to publish news stories about how new clinical studies have affirmed that non-fasting blood samples are acceptable for cholesterol testing. When patients understand the benefits of this new way to perform cholesterol testing, they will ask their physicians about it.
Meanwhile, medical professionals and clinical laboratories have the opportunity to use dynamic scheduling (AKA Dynamic Priority Scheduling) to take advantage of cholesterol testing that uses non-fasting blood specimens. Patients can submit samples immediately after the first appointment with their doctor, allowing for faster follow-ups, and lowering the overall cost and time requirements for treatments. Medical laboratories will also find relief from the initial morning surge of patients waiting to draw samples, allowing for more consistent scheduling and the ability to handle requests with increased efficiency.
This approach is similar to one used in Denmark where non-fasting blood sampling has been the standard practice since 2009. Citing samples measured at Herlev Hospital and Copenhagen University Hospital from 2011 to 2015, researchers noted, “of 60,000 triglyceride measurements, only 10% were measured in the fasting state. Further, among the 5,538 patients with both a non-fasting and a fasting triglyceride measurement, concentrations were very similar in fasting and non-fasting measures overall, as well as when stratified by triglyceride concentrations and the presence or absence of diabetes.”
While the study highlights the minimal impact of a healthy diet on test results, researchers warn that consumption of fast-food and other unhealthy items shortly before testing might cause abnormal triglyceride results. They recommend that medical professionals encourage patients to avoid high-fat, fast-food meals up to 24 hours prior to drawing a sample.
Assessing the Risk of Non-Fasting Blood Sampling for Medical Lab Testing
There are situations in which the study cites that fasting samples are beneficial. Researchers recommend using fasting blood sampling when non-fasting triglycerides exceed 5mmol/L, when hypertriglyceridemia is known or suspected, or when other laboratory tests ordered require fasting or morning samples.
They further note, “Common sense must prevail and a distinction made between their use in screening, assessment, and diagnosis. Fasting is less critical for first-stage screening, but may be more important when trying to establish a phenotypic diagnosis of genetically determined dyslipidemias.”
Researchers noted that an increase in unhealthy lifestyles, and the differences in results based on regions or other demographics, make it difficult to create universal reference values. They also note that policies will differ depending on ethnic groups. All of this is further complicated by comorbidities and other considerations often unavailable to clinical laboratories.
To address these concerns, the study’s authors proposed an abnormal flagging system based on moderate risk reference values. Researchers stated, “such flagging emphasizes the importance of harmonization and standardization in laboratory medicine.”
Changing the Current Standard of Practice Regarding Cholesterol Testing
Outlining a proposed adoption plan to shift toward non-fasting sampling as standard practice, researchers believe that the best option moving forward is to start with key research and university hospitals. As more data is established, medical societies and the media can help to highlight the improvements offered. With the support of the medical community and clinical laboratories, the authors hope that it will become clear that fasting is no longer a required part of lipid screening for most individuals.
Fasting is Not Routinely Required for Determination of a Lipid Profile: Clinical and Laboratory Implications Including Flagging at Desirable Concentration Cut-Points—A Joint Consensus Statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine