RAISED LIPOPROTEIN(A) IN HYPERCHOLESTEROLEMIC BLACK-STUDENTS COMPAREDTO AGE-MATCHED WHITES IN NORTH AND SOUTH-CAROLINA

Background: North and South Carolina are the states with the highest c oronary death rates and also belong to the 'Stroke Belt' of the US. Fr om a Reflotron cholesterol screening in North and South Carolina schoo ls, students with cholesterol levels greater than or equal to 4.66 mmo l/l (greater than or equal to 180 mg/dl) were tested for high density lipoprotein (HDL), low density lipoprotein (LDL) and lipoprotein(a) (L p(a)). Methods: The 923 students aged 12-19 with mild hypercholesterol aemia represented one-third of the high school population, of whom 30% are black. Of the hypercholesterolaemic white students, 96% took the additional tests, of the hypercholesterolaemic black students, 88% res ponded. Lp(a) levels were determined by electroimmunodiffusion. Result s: Most important was a three-fold elevation of the geometric mean of Lp(a) values among blacks compared to whites: white males 9, white fem ales 10, black males 25, black females 26 mg/dl, respectively, indepen dent of age and sex. Relationships between Lp(a) and four other lipids /lipoproteins were examined and proved non-significant except for tota l cholesterol and LDL in black males and white females. While 70% of t he white students displayed Lp(a) levels < 20 mg/dl, 65-70% of the bla ck students showed Lp(a) levels > 20 mg/dl. Conclusions: Early identif ication of high Lp(a) levels may be of importance for two groups, (1) black females who have a 20% higher coronary heart disease mortality r ate than white females in spite of significantly higher HDL levels; an d (2) for black males and black females who have a prevalence of cereb rovascular disease twice as high as in whites.