Due to recent advances in the treatment of hypercholesterolemia,
low density lipoprotein (LDL) cholesterol
concentrations below 2.6 mmol/l have become attainable.
In general, LDL cholesterol is determined indirectly
according to Friedewald. We examined the performance
of the Friedewald formula at low
concentrations of LDL cholesterol in comparison with
a β-quantification method. We analyzed 176 samples
from individuals treated by LDL apheresis with a mean
LDL cholesterol concentration of 3.07 mmol/l and
found that the Friedewald formula underestimated
LDL cholesterol with a bias of −18.5%, −14.5%, −7.3%,
and −3.8% at mean LDL cholesterol levels of 1.58, 2.4,
3.49, and 4.67 mmol/l, respectively. Thus, the lower
the LDL cholesterol concentration was, the greater the
negative bias. We conclude that the Friedewald formula
may not be reliable at low LDL cholesterol concentrations
produced by LDL apheresis. This finding
may also be of relevance to the monitoring of patients
being treated with lipid lowering drugs.
Clinical Chemistry and Laboratory Medicine (
CCLM) publishes articles on novel teaching and training methods applicable to laboratory medicine.
CCLM welcomes contributions on the progress in fundamental and applied research and cutting-edge clinical laboratory medicine. It is one of the leading journals in the field, with an impact factor of over three.
CCLM is the official journal of nine national clinical societies and associated with EFLM.
01 Jan 1963
Philippe Gillery, Ronda Greaves, Karl J. Lackner, Giuseppe Lippi, Bohuslav Melichar, Deborah A. Payne and Peter Schlattmann