Childhood levels of serum apolipoproteins B and A-I predict carotid intima-media thickness and brachial endothelial function in adulthood: the cardiovascular risk in young Finns study.

Description

In order to investigate the association between lipid indices measured at childhood and atherosclerosis at adulthood, investigators of the Cardiovascular Risk in Young Finns study sought to examine whether apolipoprotein B and apolipoprotein AI were associated with incident carotid intima-media thickness (cIMT) as well as brachial artery flow-mediated dilation (FMD). For that purpose, a complete lipoprotein-lipid profile was obtained in 1980 and in 2001 among 879 participants 3 to 18 years old. In children aged 12 to 18, apolipoprotein B and apolipoprotein AI, as well as the apolipoprotein B/apolipoprotein AI ratio, were found to be associated with cIMT at adulthood. However, this relationship was not observed in children 3 to 9 years of age at the baseline examination. Apolipoprotein AI was inversely related to FMD in subjects 3 to 9 years of age and in participants 12 to 18 years of age. In these categories, the apolipoprotein B/apolipoprotein AI ratio, but not apolipoprotein B alone, also predicted FMD. In children aged 12 to 18, the apolipoprotein B/apolipoprotein AI ratio also added significant information on cIMT to the LDL cholesterol/HDL cholesterol ratio. The c-statistic of the apolipoprotein B/apolipoprotein AI ratio was 0.623 compared to the c-statistic for LDL cholesterol/HDL cholesterol, which was significantly lower (0.569, p=0.03). Based on the findings, the authors concluded that risk factors observable early in life might have effects on arterial health and that the apolipoprotein B/apolipoprotein AI ratio might be of significant value in pediatric lipid risk assessment. The article was accompanied by an editorial by Allan D. Sniderman who explained that the risk associated with high LDL cholesterol levels is likely due to the number of circulating LDL particles rather than the cholesterol content of these atherogenic lipoproteins. He again pointed out that apolipoprotein B is a very good marker of the number of circulating atherogenic lipoproteins and that its clinical relevance was further highlighted by the study by Juonala et al. Sniderman also added that an important finding of that study was that atherosclerosis is well underway by the third or fourth decades of our lives and that the progression of this disease can be predicted very early in life.