Comparison of direct and indirect measurement of LDL-C in HIV-infected individuals: ACTG 5087.

TitleComparison of direct and indirect measurement of LDL-C in HIV-infected individuals: ACTG 5087.
Publication TypeJournal Article
Year of Publication2007
AuthorsEvans SR, Fichtenbaum CJ, Aberg JA
Corporate AuthorsA5087 Study Team
JournalHIV Clin Trials
Volume8
Issue1
Pagination45-52
Date Published2007 Jan-Feb
ISSN1528-4336
KeywordsClinical Trials as Topic, Fenofibrate, HIV, HIV Infections, Humans, Hyperlipidemias, Hypolipidemic Agents, Lipoproteins, LDL, Reagent Kits, Diagnostic, Sensitivity and Specificity, Triglycerides, Ultracentrifugation
Abstract

BACKGROUND: Hypertriglyceridemia is common in HIV-infected individuals on antiretroviral therapy. Triglyceride (TG) levels >400 mg/dL interfere with the accurate determination of low-density lipoproteins (LDL-C) by the Friedewald equation, making it difficult to assess coronary heart disease risk.

OBJECTIVE: The objective of this study is to compare the agreement of the direct LDL-C assay and the Friedewald equation with a reference ultracentrifugation method in the estimation of LDL-C concentrations.

METHOD: Samples from ACTG 5087 were assayed by ultracentrifugation and a direct enzymatic assay and calculated using the Friedewald equation.

RESULTS: In subjects with TG <400 mg/dL (n = 271), 90% of the direct LDL-C values and Friedewald calculations were within 30 mg/dL and 32 mg/dL of the ultracentrifugation values, respectively. With TG > or = 400 mg/dL (n = 186), 90% of the direct assay and Friedewald observations were within 68 mg/dL and 120 mg/dL of the ultracentrifugation results, respectively. Only 27% of the LDL-C values were within 15 mg/dL of the ultracentrifugation LDL-C results for direct assay and 16.3% for the Friedewald equation.

CONCLUSION: The direct LDL-C assay and the calculated LDL-C values did not display adequate agreement with the reference ultracentrifugation method. In subjects with TG >400 mg/dL, the direct assay overestimates the actual LDL-C whereas the Friedewald calculation underestimates the actual LDL. Clinical usage of these methods may lead to misclassification of the severity of dyslipidemia, resulting in improper management.

DOI10.1310/hct0801-45
Alternate JournalHIV Clin Trials
PubMed ID17434848
PubMed Central IDPMC2288650
Grant List1 U01 AI069532-01 / AI / NIAID NIH HHS / United States
AI038855-08 / AI / NIAID NIH HHS / United States
AI25897 / AI / NIAID NIH HHS / United States
AI27665 / AI / NIAID NIH HHS / United States
AI69513 / AI / NIAID NIH HHS / United States
M01 RR00096 / RR / NCRR NIH HHS / United States
U01 AI027665 / AI / NIAID NIH HHS / United States
U01 AI027665-18 / AI / NIAID NIH HHS / United States
U01 AI027665-18S1 / AI / NIAID NIH HHS / United States
U01 AI027665-18S2 / AI / NIAID NIH HHS / United States
U01 AI038858 / AI / NIAID NIH HHS / United States
U01 AI038858-09S3 / AI / NIAID NIH HHS / United States
U01 AI038858-09S4 / AI / NIAID NIH HHS / United States
U01 AI068636 / AI / NIAID NIH HHS / United States
U01 AI068636 / AI / NIAID NIH HHS / United States
U01 AI068636-01 / AI / NIAID NIH HHS / United States
U01 AI069532 / AI / NIAID NIH HHS / United States
U01 AI069532-01 / AI / NIAID NIH HHS / United States
U01 AI38558 / AI / NIAID NIH HHS / United States