Children may not need to fast before lipid screening
MedWire News: Fasting before lipid screening may be unnecessary in children, according to US researchers who found small, but "likely unimportant," differences in cholesterol screening results for a nonfasting group of children, compared with results for a similar fasting group.
Writing in the journal Pediatrics, Michael Steiner and colleagues, from the University of North Carolina at Chapel Hill, say: "Although statistically significant, these differences are unlikely to result in important clinical changes in the results of screening for cholesterol abnormalities."
Using data from the National Health and Nutrition Examination Survey (1999-2008), the researchers examined differences in pediatric lipid values, based on the duration of fast before testing.
Total cholesterol, triglyceride, high-density lipoprotein (HDL), or low-density lipoprotein (LDL) cholesterol values were available for 12,744 children, aged between 3 and 17 years. Of these, 48% of the total and HDL cholesterol samples, and 80% of the LDL cholesterol and triglyceride samples were collected from children who had fasted for 8 hours or more.
The researchers report that there were only small changes in lipid measurements based on number of hours of fasting.
Specifically, fasting had a small positive effect for total, HDL, and LDL cholesterol, resulting in a mean value for the sample that was between 2 and 5 mg/dl (0.05 and 0.13 mmol/l) higher with a 12-hour fast than with no fast.
Fasting time had a negative effect on triglycerides, the team adds, resulting in values 7 mg/dl (0.08 mmol/l) lower in the fasting than in the nonfasting group.
Using American Academy of Pediatrics (AAP) cutoffs, nonfasting screening inappropriately classified approximately 1.0% and 1.2% of children as normal based on total and LDL cholesterol levels, respectively, who would have had borderline values with fasting. For triglycerides, approximately 4.0% of the children classified with normal triglycerides when fasting would have had elevated values if they had not fasted.
"The AAP currently recommends a fasting lipid panel on any child or adolescent with an increased risk of hyperlipidemia or other cardiovascular risk factors," explain the researchers.
However, preparing for the fasting state makes screening recommendations more burdensome, they say, and may even make the screening process more expensive, because of the need for return visits, transportation expenses, and missed work and/or school.
Steiner et al conclude that, if their findings are confirmed, "professional societies might wish to reconsider their recommendations and encourage providers follow lipid screening guidelines at the point of care, regardless of fasting status."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Nikki Withers