‘No fasting’ for cholesterol test
Patients may not need to fast before having their cholesterol tested, a major report has found. After analysing data from 300,000 people, Cambridge researchers found results were just as accurate if the patient had eaten before the test.
For decades patients have been told to fast for 12 hours prior to a test. It is hoped the study, published in the Journal of the American Medical Association, may inform new guidelines for doctors in the UK.
Cholesterol tests have long been a key part of assessing a patient’s risk of cardiovascular problems, and those who turned up having eaten breakfast were required to make a fresh appointment.
It had been thought that the body needed enough time to digest food in the system and to clear any fatty particles from the blood in order to produce an accurate reading of so-called “bad” cholesterol – or low-density lipoprotein (LDL).
But data from 68 long-term surveys in 21 countries suggests this is not the case. “For decades, people have been asked to fast overnight before their cholesterol tests,” lead researcher Professor John Danesh said.
“These findings indicate that cholesterol measurements are at least as good – and probably somewhat better – when made without fasting.” The study also adds to the ongoing controversy over whether testing for blood proteins called apolipoproteins is a more reliable way of predicting heart risk than cholesterol testing.
The studies showed that analysing “good” cholesterol – or high-density lipoprotein (HDL) in conjunction with LDL was just as informative as testing for apolipoproteins AI and B.
Professor Peter Weissberg, medical director of the British Heart Foundation, said: “Given the financial pressure the NHS is under, it’s good news that doctors don’t need to spend money on setting up more sophisticated tests based on apolipoproteins.
“But the study underlines the importance of all GPs being able to measure HDL cholesterol as well as total cholesterol, in order to make the best predictions about heart disease risk.”
Not all doctors currently use tests which differentiate between the two different forms of cholesterol.
Societies involved with heart care are currently drawing up new guidelines for health professionals in the UK, where cardiovascular disease – CVD – is the leading form of death.