Nonfasting lipids ‘preferable’
medwireNews: Patients may no longer have to fast before having their blood lipid levels tested, suggest latest research findings.
"Fasting for routine lipid level determinations is largely unnecessary," report Dr Christopher Naugler (University of Calgary, Canada) and colleagues in the Archives of Internal Medicine.
In a cross-sectional analysis of laboratory data collected over a 6-month period for 209,180 individuals, the researchers found no relationship between fasting duration and lipid subclass levels. Mean levels varied according to fasting time by less than 2% for total cholesterol and high-density lipoprotein cholesterol, by less than 10% for low-density lipoprotein cholesterol, and by less than 20% for triglycerides.
The researchers note that several other studies have recently suggested that the measurement of nonfasting lipid subclasses is acceptable, with some nonfasting markers proving superior for assessment of risk for cardiac events.
"Furthermore, as humans are usually in a nonfasting state, nonfasting values may be more representative of usual metabolic conditions," they point out.
In addition, the approach could improve adherence to screening programmes, the team reasons. Patients are inconvenienced by having to fast for routine blood tests, even more so because fasting bloods are usually conducted in the morning hours, resulting in long waiting times at phlebotomy clinics.
In an accompanying editorial, Dr Michael Gaziano (Harvard Medical School, Boston, USA) notes that, given most decisions depend on total and high-density lipoprotein cholesterol levels, "the incremental gain of a fasting profile is exceedingly small… and likely does not offset the logistic impositions placed on our patients".
He adds: "This, in my opinion, tips the balance toward relying on nonfasting lipid profiles as the preferred practice."
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