TY - JOUR
T1 - Performance of calculated and directly measured low-density lipoprotein cholesterol in a pediatric population
AU - Roper, Stephen M.
AU - Cao, Jing
AU - Tam, Estella
AU - Devaraj, Sridevi
N1 - Publisher Copyright:
© American Society for Clinical Pathology, 2017.
PY - 2017
Y1 - 2017
N2 - Objectives: An assessment of methods for the accurate measurement of low-density lipoprotein cholesterol (LDLC) at decreased concentrations has not yet been carried out. We evaluated the performance of the Friedewald equation, a direct enzymatic assay, and a novel equation for determining LDL-C levels in a pediatric population with elevated triglycerides and reduced LDL-C levels. Methods: LDL-C concentrations of 127 pediatric patients were determined by the Friedewald equation, a direct enzymatic assay, and a novel equation. The bias of each approach was assessed at selected LDL-C cutoffs and after stratifying samples by triglyceride content. The concordance of each approach, relative to the reference method, was determined at LDL-C cut-points of less than 70, 70 to 99, and 100 to 129 mg/dL. Results: The Friedewald equation substantially underestimated pediatric LDL-C concentrations below 100 mg/dL in the presence of elevated triglycerides. The Ortho Clinical Diagnostics (Raritan, NJ) direct LDL assay was positively biased at low LDL-C levels. The novel equation most effectively reduced the bias of the Friedewald equation at all LDL-C concentrations and increased the concordance of sample classification to the reference method. Conclusions: The novel equation should be used for accurate measurement of pediatric LDL-C when the concentration is below 100 mg/dL in the presence of elevated triglycerides (150-399 mg/dL). .
AB - Objectives: An assessment of methods for the accurate measurement of low-density lipoprotein cholesterol (LDLC) at decreased concentrations has not yet been carried out. We evaluated the performance of the Friedewald equation, a direct enzymatic assay, and a novel equation for determining LDL-C levels in a pediatric population with elevated triglycerides and reduced LDL-C levels. Methods: LDL-C concentrations of 127 pediatric patients were determined by the Friedewald equation, a direct enzymatic assay, and a novel equation. The bias of each approach was assessed at selected LDL-C cutoffs and after stratifying samples by triglyceride content. The concordance of each approach, relative to the reference method, was determined at LDL-C cut-points of less than 70, 70 to 99, and 100 to 129 mg/dL. Results: The Friedewald equation substantially underestimated pediatric LDL-C concentrations below 100 mg/dL in the presence of elevated triglycerides. The Ortho Clinical Diagnostics (Raritan, NJ) direct LDL assay was positively biased at low LDL-C levels. The novel equation most effectively reduced the bias of the Friedewald equation at all LDL-C concentrations and increased the concordance of sample classification to the reference method. Conclusions: The novel equation should be used for accurate measurement of pediatric LDL-C when the concentration is below 100 mg/dL in the presence of elevated triglycerides (150-399 mg/dL). .
KW - Calculated LDL-C
KW - Direct-measured LDL-C
KW - Friedewald equation
KW - Low-density lipoprotein cholesterol
UR - http://www.scopus.com/inward/record.url?scp=85028979197&partnerID=8YFLogxK
U2 - 10.1093/AJCP/AQX042
DO - 10.1093/AJCP/AQX042
M3 - Article
C2 - 28575159
AN - SCOPUS:85028979197
SN - 0002-9173
VL - 148
SP - 42
EP - 48
JO - American journal of clinical pathology
JF - American journal of clinical pathology
IS - 1
ER -