Apolipoproteins A-I and B and the B/A-I Ratio in the First Year of Life

Abstract

ABSTRACT. To investigate early detection of young families with inherited dyslipidemia, we assessed changes in circulating apolipoprotein (apo) B and A-I levels and the apo B/A-I ratio during the 1st year of life and their relations to parental values. After measuring initial dried blood spot capillary blood levels in 919 babies when aged 4.25 f 0.98 d (mean 2 SD), we recalled at a mean age of 8.5 f 2.3 mo those with levels in one or more of the following categories: the top 5% of apo B values (group I), the top 5% of apo B/A-I ratios (group 2), the bottom 5% of apo A-I values (group 3), and a group of 18 infants (group 4) who were not in any of the above three categories. We thus obtained serum lipid measurements in 51 infants and their parents. Two of the 13 group 1 infants had persistent hyperapo B at 8.5 mo; there was an inverse relationship between apo B and apo A-I levels in this group ( p < 0.001). Two of 11 babies in group 2 had lipid profiles consistent with familial hypercholesterolemia. However, none of the infants in group 3 had evidence at 8.5 mo of abnormal apo A-I or HDL levels, nor did their parents. For groups 1, 2, and 3, there was at 8.5 mo a regression of apo B and A-I toward mean levels for the "normal" 18 babies of group 4. In contrast, the high apo B/A-I ratios in group 2 remained high ( p < 0.01) and showed evidence of tracking. Correlations between birth weight and apo B (positive) and apo A-I (negative) that were found previously at 1 wk were still evident at 8.5 mo. Thus, individual apo B/A-I ratio measurements during the'lst week of life are predictive of levels at 8.5 mo, and this finding may facilitate familial hypercholesterolemia detection. Persistence of significant correlations between birth weight and apolipoprotein levels suggests an ongoing relationship between birth weight and subsequent lipid metabolism. (Pediatr Res 30: 544-549, 1991) Abbreviations apo A-I, apolipoprotein A-I apo B, apolipoprotein B apo(a), apolipoprotein(a)In a recent study we measured apo A-I, the principal protein moiety of the antiatherogenic HDL cholesterol, and apo B, the carrier protein for the atherogenic LDL cholesterol, in 919 consecutively born neonates of birth weights 2 kg or greater when they were 2 to 5 d old (1). We wished to assess the variables affecting both of these apolipoproteins in the neonatal period Supported by the National Heart Foundation of Australia. 5and to explore the hypothesis that the ratio of apo B to A-I when measured in dried blood spots obtained during routine neonatal screening programs could identify families with genetically determined dyslipidemias associated with increased cardiovascular risk. Levels of these apolipoproteins may be better predictors of coronary risk than HDL and LDL cholesterol (2-4). Our ultimate aim is to facilitate family-based coronary prevention directed to young parents with dominantly inherited dyslipidemia in the expectation that this would also benefit the children themselves when older (5). Our studies showed that birth weight, day ...

Screening for hypercholesterolaemia in 10,000 neonates in a multi-ethnic population

“…ApoB showed a highly skewed distribution, as expected with such a high number of very low values (<0.02 g/L) and a slight variation between males and females. The same pattern of overall frequency distributions was found by Wang et al [18] who suggest that the skewed distribution for apoB may be due to the contribution of genetic and perinatal factors and that there is a possibility of greater variability of apoB gene expression in the 1st week of life.…”

“…Wang et al [18] also found that apoA-1 correlated negatively with birth weight. Birth weight may be a measure of the maturity of the infant (since the study does not take into account gestational age as this is not indicated on the sample request cards) and heavier individuals could be more mature and thus have more established levels of apolipoproteins.…”

“…Birth weight may be a measure of the maturity of the infant (since the study does not take into account gestational age as this is not indicated on the sample request cards) and heavier individuals could be more mature and thus have more established levels of apolipoproteins. Indeed, Wang et al [18] did ®nd apoA-1 increased with age at sampling. Apolipoprotein B did not correlate with birth weight in contrast to Wang et al [18], but the group did use a very dierent assay method.…”

Changes in serum lipid and lipoprotein concentrations and compositions at birth and after 1 month of life in macrosomic infants of insulin-dependent diabetic mothers

“…This is of considerable interest in view of the predictive value of this ratio for cardiovascular risk. Wang et al [32] reported that infants with an initially high apo B-100/apo A-I ratio still had high values at the age of 8.5 months.…”

Impaired Serum Lipids and Lipoproteins in Fetal Macrosomia Related to Maternal Obesity

“…The most useful marker ratios of atherogenic risk (apo B100/apo A-I, LDL cholesterol/HDL cholesterol, HDL 3 cholesterol/ HDL 2 cholesterol) were all significantly higher in macrosomic compared to other newborns. The apo B100/apo A-I ratio, the most sensitive atherogenic index, is found to track closely during the 1st year of life [29]. Thus, persisting lipoprotein abnormalities in these macrosomic infants could be one of the processes that link macrosomia with adult metabolic diseases [10].…”