Lipoprotein(a) in Vascular Disease, Cancer and Longevity

Lipoprotein(a) [Lp(a)] is a unique lipoprotein with controversial functions. Lp(a) contains apolipoprotein(a) [apo(a)]covalently attached to apolipoprotein B on the low-densitylipoprotein (LDL) particle. The distribution of blood Lp(a)concentrations in several populations have been found to beskewed with Lp(a) being mostly present at low level (0 – 200mg/L). A high Lp(a) concentration (greater than 200 mg/L) inblood increases the risk of various vascular diseases includingchronic heart disease, acute myocardial infarction and cerebralthrombosis. With Lp(a) potentially having such deleteriouseffects, there is a need to ask what are the evolutionary benefit(s) of Lp(a) to humans and other mammals that have it.Lp(a) has been reported to offer a number of benefits such asproviding protection from LDL cholesterol and providing asource of cholesterol in wound tissue. Furthermore, some evidence is emerging that Lp(a) has anti-tumor properties. Other surveys have indicated thatLp(a) is advantageous because it promotes longevity. Lp(a) is only found in humans, oldworld monkeys and hedgehogs. Individuals who do not express Lp(a) do not show any disease symptoms, which indicates that Lp(a) is not essential for human life. It still remainsunclear why mysterious Lp(a) has evolved and is present in humans. (