Lp(a) lipoprotein level and longevity.

Lp(a) lipoprotein forms a distinct class of serum lipoproteins. Its unique immunochemical properties are caused by the Lp(a) polypeptide chain which is attached to apolipoprotein B (apoB) by a disulfide bridge. The level of Lp(a) lipoprotein is under strict genetic control. It is well established that a high level of Lp(a) lipoprotein is a genetic risk factor for atherosclerotic disease, particularly coronary heart disease (CHD). Since cardiovascular disease is one of the major causes of death there should be a shortage of people with genetic determinants of cardiovascular disease in people who are very old and still have adequate physical and mental capacities. The authors have studied Lp(a) lipoprotein levels in 102 persons who were 83 years or older when blood samples were drawn. This study group was a subpopulation of a series comprising 456 persons who had been 80 years or older at intake in an intervention study of old people living at home. Only those without physical or mental incapacities were included in the present study. There was a striking shortage of persons with an Lp(a) lipoprotein level higher than the 75th percentile of the general population in this series of people who had achieved successful ageing. The highest value observed among the old people corresponds to the 88th percentile of the general population. It is highly unlikely that the present observations reflect chance events or fall in Lp(a) lipoprotein levels in people who had higher levels at a younger age. The most likely explanation of our finding is that a sizeable fraction of people with high Lp(a) lipoprotein levels die before reaching a very high age.(ABSTRACT TRUNCATED AT 250 WORDS)