Relationship between 'sinking pre-beta-lipoprotein' (Lp(a) lipoprotein) and age in a family kindred

Serum Lp(a) levels have been measured in a family kindred of three generations by Laurell electrophoresis. It was found that individuals with Lp(a) levels exceeding 30 mg/dl exhibited an extra pre-beta-band in agarose gel electrophoresis (sinking pre-beta positive), and a significant positive correlation existed between serum Lp(a) levels and age. A positive correlation between Lp(a) and total serum cholesterol was observed only in sinking pre-beta-positive individuals, but not in sinking pre-beta-negative individuals with Lp(a) levels of less than 30 mg/dl. These findings are not contradictory to the assumption that Lp(a) might be an independent rise factor for atherosclerosis.