Margaret A.WinkerMDIndividualAuthorPhil B.FontanarosaMD, Senior EditorsIndividualAuthor
In Reply.—Dr Enas legitimately emphasizes the need to consider plasma triglyceride and apolipoprotein B concentrations as clinical surrogates for the presence of small, dense LDL particles in order to improve our ability to predict ischemic heart disease risk. Plasma triglyceride levels may indeed represent the most relevant crude surrogate for LDL particle size. We have previously reported that a plasma triglyceride cutoff point of 1.90 mmol/L (168 mg/dL) corresponded to the value at which both optimal sensitivity (84%) and specificity (83%) were obtained.1 Similar results were obtained when we analyzed the data from the Quebec Cardiovascular Study (results available on request). This cutoff point is substantially higher than the value suggested by Enas (1.13 mmol/L [100 mg/dL]). However, the small, dense LDL phenotype remains an "arbitrary" phenotype because there is currently no agreement on the LDL particle size value above which CHD risk is increased. Thus, it may well be that deleterious changes in LDL particle size in terms of ischemic heart disease risk may occur at plasma triglyceride values of 1.40 to 1.60 mmol/L (124-142 mg/dL).
Lamarche B, Dagenais GR, Després J. Triglycerides and Small, Dense Low-Density Lipoprotein—Reply. JAMA. 1998;280(23):1990–1991. doi:10-1001/pubs.JAMA-ISSN-0098-7484-280-23-jbk1216
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