Low density lipoprotein in neonates with high cord serum cholesterol levels

Enhanced delivery of lipophilic nutrients to the infant brain via high density lipoprotein

Lipoproteins are the primary carriers of lipophilic cognitive nutrients such as docosahexaenoic acid, lutein, and α-tocopherol within circulation. The critical roles these nutrients play in growth and development are well established, and as such, their efficient delivery to the infant brain is crucial. Given the selectivity of the blood brain barrier, the lipoprotein fraction primarily responsible for brain delivery of these nutrients must be determined so that efforts aimed at increasing brain nutrient uptake, via lipoprotein profile manipulation, can be appropriately focused. Based on the preclinical and clinical data reviewed here, we hypothesize that high density lipoprotein is the fraction chiefly responsible for delivery of docosahexaenoic acid, lutein, and α-tocopherol to the infant brain. As high density lipoprotein levels tend to be lower in preterm, formula-fed infants as compared to their full-term, breast-fed counterparts, efforts aimed at increasing circulating high density lipoprotein levels, and subsequent delivery of cognitive lipophilic nutrients to the brain via manipulation of formula composition, may be most effective if targeted to this group. These efforts include (1) limiting the polyunsaturated: saturated fatty acid ratio; (2) increasing the casein: whey ratio; (3) altering the proportion of saturated fatty acids found in the sn-2 position of the parent triglyceride; (4) cholesterol supplementation; and (5) nucleotide supplementation.

Effects of APOA5 S19W polymorphism on growth, insulin sensitivity and lipoproteins in normoweight neonates

Apolipoprotein (Apo) A5 is a protein involved in the activation of lipoprotein lipase (LPL) and the metabolism of triglyceride (TG)-rich lipoproteins. LPL plays a major role in the metabolism of TG-rich lipoproteins, and placental LPL activity is known to correlate positively with foetal fat deposition and size. We examine the association between the common APOA5 S19W polymorphism and neonatal anthropometrical measurements, lipoprotein and hormone concentrations, and insulin sensitivity in 58 normal weight Caucasian newborns from the Mérida cohort. Neonates with the W allele displayed lower BMI (P < 0.001), ponderal index (P < 0.001), birth weight (P < 0.01), insulin levels (P < 0.05), the insulin/cortisol ratio (P < 0.05), HOMA-R (P < 0.05) and Apo B values (P < 0.01), but higher oxidised LDL (LDLox) values and a higher LDLox/low-density lipoprotein (LDL) ratio (both P < 0.05) than S-homozygous newborns. The APOA5 S19W polymorphism was associated with foetal growth as well as with glucose and lipoprotein metabolism in the neonates. Concurrence of the S19W polymorphism in neonates and their mothers did not affect neonatal lipid and lipoprotein concentrations but was associated with impaired foetal growth. Specifically, W allele carriers displayed a higher degree of LDL oxidation and lower body weight, plasma insulin values, insulin/cortisol ratio and Apo B concentrations than homozygotes for the common S allele. In conclusion, these findings suggest that the W allele carriers received a less optimal nutrition during gestation and that their lipoprotein antioxidant status was inferior to that of their homozygous S allele counterparts.

Cord Blood Lipids in Infants Born to HIV-1-Infected Women Treated with Combination Antiretroviral Therapy

Background

To investigate the effect of exposure to protease inhibitor (PI) therapy in utero on cord blood lipids in infants born to mothers enrolled in AIDS Clinical Trials Group protocol 5084, a prospective, multi-centre, observational study of antiretroviral therapy (ART) during pregnancy.

Methods

Clinical outcome was determined in 80 infants born to women treated with PIs and 73 infants born to women treated with other antiretrovirals during pregnancy. Cord blood serum from 117 of these infants was assayed for total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, triglyceride, apolipoprotein A1 (apoA1), apolipoprotein B100 (apoB) and lipoprotein (a). Covariates considered in the analysis included race/ethnicity, gestational age, infant gender, infant birth weight, mode of delivery, maternal tobacco and alcohol use, post-partum body mass index, and ART duration.

Results

Cord blood total and HDL cholesterol, triglyceride, apoA1, apoB, lipoprotein (a) and apoB/apoA1 ratio were not different between the two groups. Cord blood lipid levels in these HIV-exposed infants were similar to those reported in other neonatal cohorts. Controlling for race/ethnicity, infants born to women treated with PIs had higher LDL cholesterol than those born to women not treated with PIs (29 mg/dl versus 27 mg/dl, P=0.006).

Conclusion

Only LDL cholesterol was significantly higher in the cord blood of PI-exposed infants versus those not exposed to PIs in utero. As the difference between the two groups was small, the clinical relevance of the effect of maternal PI treatment on infant LDL cholesterol levels at birth is not clear.

The Effect of Nutritional Habits on Maternal-Neonatal Lipid and Lipoprotein Serum Levels in Three Different Ethnic Groups

AIM

To investigate the effect of nutritional habits on lipid profiles in mothers of three different ethnic groups and in their newborns.

SUBJECTS AND METHODS

Lipids and lipoproteins were determined in 7-day dietetic diaries of 9,134 mothers (Greeks n = 3,118, Albanians n = 3,050, Muslim Asians n = 2,966), in their sera and in the cord blood of their newborns with routine methods.

RESULTS

Monounsaturated fat intake (35 +/- 12 g/day) was similar among the groups. Total fat, saturated fat and cholesterol intakes were significantly lower in Asians than those in Albanians and Greeks. Significantly lower lipid and lipoprotein concentrations (cholesterol 5.09 +/- 0.85 mmol/l, triglyceride, TG, 2.38 +/- 0.58 mmol/l, low-density lipoprotein cholesterol, LDL-C, 2.90 +/- 0.78 mmol/l, very-low-density lipoprotein cholesterol, VLDL-C, 0.32 +/- 0.11 mmol/l) were measured in the Muslim Asian mothers and in their newborns (cholesterol 1.06 +/- 0.26 mmol/l, TG 0.52 +/- 0.16 mmol/l, LDL-C 0.49 +/- 0.10 mmol/l and VLDL-C 0.10 +/- 0.02 mmol/l; p < 0.001). Higher levels of the mentioned biochemical parameters were found in Greek mothers versus their newborns (cholesterol 5.20 +/- 0.98 mmol/l, TG 2.37 +/- 0.62 mmol/l, LDL-C 3.40 +/- 0.85 mmol/l and VLDL-C 0.48 +/- 0.13 mmol/l vs. cholesterol 1.55 +/- 0.31 mmol/l, TG 0.56 +/- 0.20 mmol/l, LDL-C 0.65 +/- 0.15 mmol/l and VLDL-C 0.12 +/- 0.01 mmol/l; p < 0.001) and Albanian mothers versus their newborns (cholesterol 7.1 +/- 0.78 mmol/l, TG 2.55 +/- 0.60 mmol/l, LDL-C 4.1 +/- 0.88 mmol/l and VLDL-C 0.52 +/- 0.13 mmol/l vs. cholesterol 1.6 +/- 0.40 mmol/l, TG 0.59 +/- 0.15 mmol/l, LDL-C 0.70 +/- 0.21 mmol/l and VLDL-C 0.12 +/- 0.01 mmol/l; p < 0.001). The highest HDL-C levels were observed in the Asian mothers (1.60 +/- 0.31 mmol/l vs. 1.4 +/- 0.39 mmol/l in Greeks and 1.31 +/- 0.39 mmol/l in Albanians; p < 0.001).

CONCLUSION

The normal lipid profile in Greeks, the high one in Albanians and the low profile in Muslim Asians may be due to their nutritional habits and their socioeconomic status affecting those of their newborns.

Cord blood lipoproteins and prenatal influences

PURPOSE OF REVIEW

Blood lipoprotein profiles in early life are known to be related to and predictive of those in adulthood, but little is known about their determinants. Genetic and environmental influences affect cord blood lipoproteins, but how this occurs and the relative contribution of these influences to the overall profile in healthy newborns remains uncertain.

RECENT FINDINGS

This review discusses findings from a range of earlier and more recent studies, and summarizes the key influences on cord blood lipoproteins. In particular, we review the potential contribution of maternal blood total cholesterol levels during pregnancy and the increased maternal transmission in newborns of mothers with diabetes.

SUMMARY

In cord blood, cholesterol levels are lower than in adults and the relative proportion present in HDL as opposed to LDL is much higher. The currently available evidence suggests that several factors influence the composition of cord blood lipoproteins. Although inheritance of major monogenic disorders can affect cord lipids in general, the genetic contribution appears to be minimal, although effects of the proprotein convertase subtilisin/kexine type 9 gene (PCSK9) need fuller exploration in this regard in certain ethnic groups. Evidence is summarized that maternal lipoprotein levels, particularly those due to diet or induced by pregnancy, influence cord lipid levels. Placental insufficiency and other conditions affecting fetal growth and the mode of delivery may also influence cord lipoprotein concentrations. How maternal glucose tolerance during pregnancy affects cord blood lipoproteins remains unclear. In view of increasing evidence that cardiovascular risk may have prenatal antecedents, this would seem to be an important area for further investigation.

Lipoprotein (a) and lipid profile in neonates from mothers with three different types of diabetes mellitus

OBJECTIVES

The metabolic components in neonates may be affected by maternal diabetes mellitus.

DESIGN AND METHODS

To investigate the alterations in lipid metabolism and the possible atherogenic risk, the lipoprotein a (Lp a), apoproteins, lipid profile, glucose concentrations were measured (ELISA, immunodiffusion and enzymatic) in 77 cord blood samples from diabetic and healthy pregnant mothers.

RESULTS

The body weight, cord glucose and both apoproteins were increased in neonates of gestational and noninsulin dependent diabetic (GDM, NIDDM) than in neonates of nondiabetic mothers (NNDM). The Lp (a) was not correlated with the blood glucose and didn't significantly increase in the three neonates groups of diabetic mothers. The apo B/apo A1 and the LDL/HDL ratios were insignificantly increased in relation to the body weight. In neonates of diabetic mothers (NDM), only the blood glucose and Lp (a) differ between both sexes.

CONCLUSION

NDM may have disturbed lipid metabolism, which require special care to them and to their mothers during the prenatal period.