August 3, 2011 (Chapel Hill, North Carolina) — Fasting does not appear to be necessary when screening cholesterol levels in children, new research suggests. Compared with children who underwent a 12-hour fast, nonfasting children had slightly lower total-, LDL-, and HDL-cholesterol levels, but investigators say these increases are unlikely to be clinically important.
"Because research findings in other populations suggest that nonfasting lipid panels can predict cardiovascular events and that the difference between fasting and nonfasting lipid panels in children is small and likely clinically insignificant, the risks of missed screening or increased screening cost as a result of recommending fasting status raise questions regarding any benefits achieved," write Dr Michael Steiner (University of North Carolina, Chapel Hill) and colleagues in a report published online August 1, 2011 in Pediatrics.
The group notes that screening for lipid disorders in kids is difficult, given that most children won't have fasted before a routine office visit. As a result, fasting lipid panels must be planned in advance or require follow-up visits to assess cholesterol levels. While fasting of eight to 12 hours is currently recommended, the researchers point out that studies in adults have suggested that an average-size meal has little impact on postprandial lipid levels.
In this analysis, the group used data from the National Health and Nutrition Examination Survey (1999–2008) to examine lipid levels on the basis of fasting. Of the 12 744 children included in the analysis, 48% of the total- and HDL-cholesterol samples and 80% of the LDL-cholesterol and triglyceride samples were taken from children who had fasted eight or more hours.
Among the children who fasted, the mean total-, LDL-, and HDL-cholesterol levels were slightly, but significantly, higher compared with children who did not fast before testing.
Among patients screened immediately after eating, the average total-cholesterol level was approximately 2 mg/dL lower compared with children who fasted, whereas LDL cholesterol was approximately 5 mg/dL lower.
Fasting had a negative effect on triglyceride levels, with levels that were 7 mg/dL lower in these patients compared with those who did not fast.
The researchers note that some studies have suggested that postprandial triglyceride levels might be a better predictor of cardiovascular risk than fasting triglycerides. Further studies will be needed to assess the utility of nonfasting lipid levels in predicting cardiovascular risk, but if they do, point-of-care lipid assessments regardless of fasting status would reduce barriers to lipid screening, according to the researchers.