A longitudinal assessment of lipid ratios in the diagnosis of type III hyperlipoproteinaemia.

Type III hyperlipoproteinaemia (HLP) has been overdiagnosed in the past, but still may go undiagnosed because of technical difficulties. This longitudinal study of 19 ultracentrifugally proven cases of Type III HLP shows that 2 lipid ratios can be used to supplement the findings of a floating beta band. These patients have been followed for 3 months to 2.5 years whilst on dietary and/or drug treatment. A group composed of more than 100 Type IIB, Type IV and Type IIB-IV hyperlipoproteinaemic patients has been used for comparison purposes. From a total of 310 ultracentrifugal analyses, it was found that the following 2 ratios have more than a 90 percent predictability for Type III HLP: supernatant cholesterol/supernatant triglyceride greater than or equal to 0.35 (Ratio 2); supernatant cholesterol/whole plasma triglyceride greater than or equal to 0.25 (Ratio 3). These ratios are particularly valuable in Type III HLP when the plasma is grossly hyperlipaemic or when the lipid levels are low because of successful treatment.