Can Measurement of Serum Apolipoprotein B Replace the Lipid Profile Monitoring of Patients with Lipoprotein Disorders?

BACKGROUND: Current clinical guidelines require that five indices (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and the total/HDL cholesterol ratio) be measured or calculated to assess the lipid-related risk of vascular disease. All five are also targets of therapy and therefore all must be measured initially and at follow-up. Considerable evidence indicates that apolipoprotein B (apo B) is a better index of reaching or not reaching treatment targets than total or LDL cholesterol. METHODS: The objective of this study was to examine whether measurement of a single marker (apo B) led to the same categorization of risk as the traditional five indices (lipid profile). If both apo B and lipid profile indicated that the patient was either within or outside their respective treatment targets, the indices were considered concordant. If not, the indices were considered discordant. Concordance/discordance was examined in 215 patients at their first and last clinic visit. RESULTS: Concordance was high in both higher (88% at the first and 92% at the last clinic visit) and lower (76% at the first and 78% at the last clinic visit) risk groups at both the initial and final visits. Discordance was virtually restricted to the group with hypertriglyceridemia with normal concentrations of apo B, a group in which little independent evidence points to any substantially increased risk of vascular disease. CONCLUSIONS: These data raise the possibility that at least for high risk patients treated with statins, follow-up could be simplified and expenses reduced if only apo B were measured. They also raise the possibility that outcome might be improved if the therapeutic algorithm were simplified.