Patients Might Not Need to Fast Before Cholesterol Testing

October 13th, 2016

COPENHAGEN, DENMARK – If you’ve had it with cranky patients who come in for a blood draw after missing breakfast and their morning coffee, new research will come as good news.

An international study involving more than 300,000 patients in Denmark, Canada, and the United States, published online recently in the European Heart Journal, suggests that fasting is no longer necessary for blood tests that check cholesterol levels. Until now, cholesterol and triglycerides have been measured in patients with empty stomachs in all countries except Denmark, where non-fasting blood sampling has been used since 2009.

"This will improve patients’ compliance to preventive treatment aimed at reducing number of heart attacks and strokes, the main killers in the world," suggested Borge Nordestgaard, MD, DMSc, of Herlev Hospital at the University of Copenhagen.

Nordestgaard pointed out that, in Denmark, patients, healthcare providers, and laboratories all have benefitted from the simplified procedure.

The recommendations were based on extensive observational data, in which random non-fasting lipid profiles have been compared with those determined under fasting conditions. Results indicate that the maximal mean changes at one to six hours after habitual meals are not clinically significant for a range of cholesterol measures.

“In addition, non-fasting and fasting concentrations vary similarly over time and are comparable in the prediction of cardiovascular disease,” according to the joint consensus statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine involving 21 medical experts from Europe, Australia, and North America.

The authors recommend that fasting sampling be considered when non-fasting triglycerides are more than 5 mmol/L (440 mg/dL). Here is how the consensus statement recommends that laboratory reports should flag abnormal concentrations:

• triglycerides ≥2 mmol/L (175 mg/dL), compared to fasting samples, where abnormal concentrations correspond to triglycerides ≥1.7 mmol/L (150 mg/dL),
• total cholesterol ≥5 mmol/L (190 mg/dL),
• LDL cholesterol ≥3 mmol/L (115 mg/dL),
• calculated remnant cholesterol ≥0.9 mmol/L (35 mg/dL),
• calculated non-HDL cholesterol ≥3.9 mmol/L (150 mg/dL),
• HDL cholesterol ≤1 mmol/L (40 mg/dL),
• apolipoprotein A1 ≤1.25 g/L (125 mg/dL),
• apolipoprotein B ≥1.0 g/L (100 mg/dL), and
• lipoprotein(a) ≥50 mg/dL (80th percentile).

The statement notes that life-threatening concentrations require separate referral when triglycerides are greater than 10 mmol/L (880 mg/dL) for the risk of pancreatitis; when LDL cholesterol is less than 13 mmol/L (500 mg/dL) for homozygous familial hypercholesterolemia; when LDL cholesterol is greater than 5 mmol/L (190 mg/dL) for heterozygous familial hypercholesterolemia; and when lipoprotein(a) is higher than 150 mg/dL (99th percentile) for very high cardiovascular risk.

“We recommend that non-fasting blood samples be routinely used for the assessment of plasma lipid profiles,” according to the consensus statement. “Laboratory reports should flag abnormal values on the basis of desirable concentration cut-points. Non-fasting and fasting measurements should be complementary but not mutually exclusive.”

Nordestgaard added, "We hope that non-fasting cholesterol testing will make more patients together with their doctors implement lifestyle changes and, if necessary, statin treatment to reduce the global burden of cardiovascular disease and premature death.”