Clinical laboratories may see a reduction in the early-morning crowds of fasting patients who have come in for cholesterol testing
For the clinical laboratory testing industry, a new Canadian study suggesting that people may not need to fast before getting a cholesterol test could prove a boon for staffing and operations at patient service centers. That’s because fasting-patients crowd phlebotomy centers in the early morning hours to get their blood drawn so they can eat breakfast.
It is standard practice to require patients to fast before drawing blood specimens for a cholesterol test. However, based on a study involving 200,000 people, findings led researchers to conclude that a non-fasting lipid test would be a reasonable alternative for most people.
Requirements for Medical Laboratory Testing
Current guidelines recommend measuring lipid levels in a fasting state, noted researchers from the University of Calgary in their abstract. The study was authored by Davinder Sidhu, M.D., LLB, and Christopher Naugler, M.Sc., M.D., CCFP, FCFP., FRCP.C..
What will interest clinical pathologists and clinical chemists is that, as reported in a story published at Reuters.com, their findings indicated similar average total cholesterol and HDL (high-density lipoprotein) cholesterol levels whether or not patients had fasted! Naugler is Zone Clinical Section Chief and Assistant Professor in the Department of Pathology and Laboratory Medicine and Sidhu is a pathology resident at the University of Calgary and Calgary Lab Services. JAMA Network Archives of Internal Medicine (AIM) published the paper.
It is a research study that could be friendly to patients and clinical laboratories alike. Researchers at the University of Calgary in Alberta have found that variation in food intake prior to testing produces minimal change in results in lipid profiles. Their examination of data from a cohort of over 200,000 patients also suggested that non-fasting lipid profiles may even be superior to fasting levels in predicting adverse cardiovascular outcomes. (Image copyright FoxNews.com.)
“This information is actually very, very interesting,” stated Suzanne Steinbaum, D.O., in a WebMD story. Steinbaum is a preventive cardiologist at Lenox Hill Hospital in New York City. She was not involved in the study. “It might change how we approach a patient,” she observed.
Researchers Analyzed a Cohort of Over 200,000 People
The purpose of the study was to investigate the association between fasting times and lipid levels, stated the authors in the abstract. They performed a cross-sectional examination of laboratory data on a large community-based cohort of more than 200,000 people. The examination took place over a six-month period in 2011. The data included both fasting duration and lipid results.
The main outcome measures were mean levels of HDL and LDL (low-density lipoprotein) cholesterol levels, total cholesterol, and triglycerides for fasting intervals from one hour to more than 16 hours.
Sidhu and Naugler calculated the average cholesterol levels at a given fasting time. They found that both total cholesterol and HDL varied by less than 2% across the range of fasting durations, Reuters reported.
“‘Bad’ LDL cholesterol, on the other hand, varied by closer to 10%, and triglycerides by up to 20%, in relation to fasting time,” the researchers wrote in AIM. “That suggests that certain patients, such as those with high triglycerides or patients who have diabetes should continue to fast before the tests.”
Requiring a Fast before Cholesterol Testing Has Disadvantages
Eliminating the fasting requirement would have benefits for patients and medical laboratories, according to the Reuters story. When labs open up each morning at 7 am or 8 am, many patient service centers are regularly deluged with a flood of patients. Patients come in for testing early because they are hungry from fasting. They want to have their specimen collected so they can have something to eat.
“There are logistic challenges when you’re going to get a fasting sample on everybody,” stated J. Michael Gaziano, M.D., MPH in the Reuters piece. Gaziano is a preventive cardiologist at VA Boston Healthcare System and Brigham and Women’s Hospital. He authored a commentary that accompanied the new study. “It makes long lines and it makes long waiting times, and if that in any way discourages patients from having these tests done, then that’s another downside,” he observed.
An additional disadvantage of requiring a fasting cholesterol test, Gaziano pointed out, is that it may mean patients have to come back for clinical laboratory work after their initial appointment. Some patients may not return.
The study had additional insights beyond demonstrating minimal changes in lab test results in lipid profiles in response to food intake. According to the abstract, results of the study also suggested that, when it comes to predicting adverse cardiovascular outcomes, non-fasting lipid profiles may be superior to fasting levels.
The abstract concluded that the data gathered in this study suggest that fasting for routine lipid subclass levels is largely unnecessary. For pathologists and clinical laboratory managers, that means that medical laboratories have an opportunity to educate physicians about these findings.
In turn, that may cause a significant reduction in the early-morning “rush hour” of hungry patients crowding into patient service centers to have their blood drawn for cholesterol testing. This would be a “patient pleasing” change. First, it would lessen the number of patients who are asked to fast before a cholestrol test. Second, it would mean more patients could visit the patient service center later in the day, and that would help clinical laboratories better adjust phlebotomy staffing to a more even demand by patients.
—Pamela Scherer McLeod
Related Information:
ABSTRACT. Fasting time and Lipid Levels in a Community-Based Population: A Cross-sectional Study
