LIPOPROTEIN(A) AND APOLIPOPROTEIN-B AND APOLIPOPROTEIN-A-I IN CHILDREN AND CORONARY VASCULAR EVENTS IN THEIR GRANDPARENTS

Because premature coronary vascular disease in a first-degree relative increases risk of the disease and the mechanisms may include genetica lly determined abnormal levels of circulating apolipoproteins, we expl ored the relationships between schoolchildren's apolipoprotein levels and coronary events in their parents and grandparents. We measured cap illary blood concentrations of lipoprotein(a) (Lp(a)) and apolipoprote ins (apo B and apo A-1) in dried blood spot samples obtained by finger prick from 2010 schoolchildren aged 8 to 12 years, and questioned par ents about coronary vascular events in the children's parents and gran dparents. Of the 2010 questionnaires sent, 1030 (51%) were returned fu lly completed. Twenty-three fathers, one mother, and 645 grandparents had had coronary vascular events. There were significant associations between increased Lp(a) levels in children and the numbers of grandpar ents with coronary vascular events and with increasing grandparent cor onary history scores (p < 0.01). There were also positive associations for apo B (p < 0.01) but none for apo A-1. Discriminate analysis show ed that the log-transformed Lp(a) level was the variable most predicti ve of event numbers and of history scores in grandparents (Wilks lambd a value = 0.984; p = 0.026); the apo B level was also predictive (Wilk s lambda value = 0.988; p = 0.041), but neither the apo A-1 level nor the apo B/A-1 ratio was. We conclude that high Lp(a) and apo B levels in children aged 8 to 12 years are associated with increased risk of c oronary vascular disease in older family members. even with a generati on gap. These apolipoproteins may largely account for the independent contribution of family history to disease risk. Measurements of Lp(a) and apo B in schoolchildren may help to identify children and their fa milies at increased risk and may facilitate targeting of prevention.