Lipoprotein (a) is composed of an LDL - like particle to which the lipoprotein (a)‑specific apolipoprotein (a) is bonded by a disulfide bridge. Apolipoprotein (a) is highly homologous to plasminogen. Lipoprotein (a) is a cholesterol‑rich lipoprotein which is synthesized in the liver independently of triglycerides and is not subject to the influence of age or diet. Lipoprotein (a) can act atherogenically and has been found in artery walls. Because of its structural similarity to plasminogen, it can also inhibit fibrinolysis and hence acts thrombogenically. High lipoprotein (a) concentrations in serum correlate with premature manifestation of atherosclerosis and strokes. When lipoprotein (a) concentrations exceed 30 mg/dL, the coronary risk is approximately doubled. In combination with elevated LDL‑cholesterol concentrations, the risk increases approximately sixfold. An elevated lipoprotein (a) level is considered to be the most sensitive parameter for the development of coronary heart disease, irrespective of other plasma lipoproteins. Lipoprotein (a) should be determined together with total cholesterol, HDL‑cholesterol and LDL‑cholesterol as well as triglycerides when assessing the total arteriosclerotic risk.