Studies in asymptomatic primary hyperlipidaemia. I. Types of hyperlipoproteinaemias and serum lipoprotein concentrations, compositions and interrelations.

1. In order to study lipoprotein (LP) abnormalities in asymptomatic subjects with hyperlipidaemia, serum cholesterol and triglycerides (TG) were determined in about 20 000 active professional men and women attending a health control linked to their employment. 2. Quantitative LP analysis with preparative ultracentrifugation, separating very low (VLDL), low (LDL) and high (HDL) density LP was subsequently performed on the sera of 314 asymptomatic subjects, who at the screening had serum cholesterol larger than or equal to 350 mg/100 ml and/or TG larger than or equal to 3.5 mmol/l. Cholesterol and TG concentrations were serum and on the top and bottom fractions after separation in the ultracentrifuge at d=1.006. Typing of hyperlipoproteinaemia (HLP) was based on the concentration of VLDL TG and LDL cholesterol and in addition, in the case of type III and V HLP, the presence of a "floating beta" LP and fasting chylomicronaemia, respectively. 3. To illustrate the lipid values in the screened total population distributions of serum cholesterol and TG are given in the age range 41-45 years. In this age range mean serum cholesterol in fasting/non-fasting state was 239+/-2/238+/-1 mg/100 ml in males and 232+/-2/239+/-2 mg/100 ml in females.