Comparison of a Homogeneous Assay With a Precipitation Method for the Measurement of HDL Cholesterol in Diabetic Patients

Comparison of a Homogeneous Assay With a Precipitation Method for the Measurement of HDL Cholesterol in Diabetic Patients Tonny Jensen , MD 1 , Quan Truong 1 , Merete Frandsen 1 , Bo Dinesen , MD 1 and Steen Stender , MD 2 1 Steno Diabetes Center, Gentofte, Denmark 2 Department of Clinical Chemistry, KAS Gentofte, Hellerup, Denmark Abstract OBJECTIVE —To compare direct-measured HDL cholesterol with HDL cholesterol measured by a precipitation method. RESEARCH DESIGN AND METHODS —We compared a homogeneous assay for direct HDL cholesterol analysis with the phosphotungstic acid magnesium chloride precipitation method in 55 type 1 diabetic patients, 70 type 2 diabetic patients, and 82 nondiabetic normal control subjects with plasma triglyceride levels 1.063; these apo B-containing lipoproteins are suggested to be coprecipitated with the phosphotungstic acid method. We also measured LDL cholesterol directly by a LDL cholesterol plus method and found no significant differences between this method and LDL cholesterol calculated from Friedewald’s formula. CONCLUSIONS —Direct homogeneous assay for HDL cholesterol determination in diabetic patients seems not to exhibit a negative bias, in contrast to the precipitation method, when compared with the ultracentrifugation method. In addition, the direct assay saves time and is not influenced by type of diabetes or degree of metabolic control. apo, apolipoprotein Footnotes Address correspondence and reprint requests to Tonny Jensen, MD, Clinic of Endocrinology, Hvidovre Hospital, 30 Kettegaard Alle, DK-2650 Hvidovre, Denmark. E-mail: tonny.jensen.tj{at}hh.hosp.dk . Received for publication 13 February 2001 and accepted in revised form 2 August 2002. A table elsewhere in this issue shows conventional