Lipoprotein profile and cholesteryl ester transfer protein in neonates

Inverse Correlation of Cholesterol Efflux Capacity with Peripheral Plaque Volume Measured by 3D Ultrasound

INTRODUCTION

Cardiovascular disease (CVD) is a systemic multifocal illness called atherosclerosis that causes artery constriction and blockage. By causing cholesterol to build up in the artery wall, hypercholesterolemia is a major factor in the pathophysiology of atherosclerotic plaque development. Reverse cholesterol transport is the process of transporting cholesterol from the periphery back to the liver through cholesterol efflux mediated by high-density lipoprotein (HDL). It was suggested that the cholesterol efflux capacity (CEC), which is inversely linked with cardiovascular risk, can serve as a stand-in measure for reverse cholesterol transport. In this work, we sought to investigate a potential link between the peripheral plaque volume (PV) and CEC.

METHODS

Since lipid-lowering therapy interferes with CEC, we performed a cross-sectional study of 176 patients (48.9% females) with one cardiovascular risk factor or known CVD that did not currently take lipid-lowering medication. CEC was determined using cAMP-treated ³H-cholesterol-labeled J774 cells. Cholesterol ester transfer protein (CETP)-mediated cholesterol ester transfer was measured by quantifying the transfer of cholesterol ester from radiolabeled exogenous HDL cholesterol to Apolipoprotein B-containing lipoproteins. PV in the carotid and the femoral artery, defined as the total PV, was measured using a 3D ultrasound system equipped with semi-automatic software.

RESULTS

In our patients, we discovered an inverse relationship between high total PV and CEC (p = 0.027). However, there was no connection between total PV and low-density lipoprotein cholesterol, lipoprotein (a), or CETP-mediated cholesterol ester transfer.

CONCLUSION

In patients not receiving lipid-lowering treatment, CEC inversely correlates with peripheral atherosclerosis, supporting its role in the pathophysiology of atherosclerosis.

Cord blood fatty acid binding protein 4 and lipids in infants born small- or large-for-gestational-age

Aim

Adverse (poor or excessive) fetal growth "programs" an elevated risk of type 2 diabetes. Fatty acid binding protein 4 (FABP4) has been implicated in regulating insulin sensitivity and lipid metabolism relevant to fetal growth. We sought to determine whether FABP4 is associated with poor or excessive fetal growth and fetal lipids.

Methods

In a nested case-control study in the Shanghai Birth Cohort including 60 trios of small-for-gestational-age (SGA, an indicator of poor fetal growth), large-for-gestational-age (LGA, an indicator of excessive fetal growth) and optimal-for-gestational-age (OGA, control) infants, we measured cord blood concentrations of FABP4 and lipids [high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterols, triglycerides (TG)].

Results

Adjusting for maternal and neonatal characteristics, higher cord blood FABP4 concentrations were associated with a lower odds of SGA [OR = 0.29 (0.11-0.77) per log unit increment in FABP4, P = 0.01], but were not associated with LGA (P = 0.46). Cord blood FABP4 was positively correlated with both LDL (r = 0.29, P = 0.025) and HDL (r = 0.33, P = 0.01) in LGA infants only.

Conclusion

FABP4 was inversely associated with the risk of SGA. The study is the first to demonstrate LGA-specific positive correlations of cord blood FABP4 with HDL and LDL cholesterols, suggesting a role of FABP4 in fetal lipid metabolism in subjects with excessive fetal growth.

Hyperemesis gravidarum severity, enteral tube feeding and cardiometabolic markers in offspring cord blood

This study aimed to investigate the association between hyperemesis gravidarum (HG) severity and early enteral tube feeding on cardiometabolic markers in offspring cord blood. We included women admitted for HG, who participated in the MOTHER randomised controlled trial (RCT) and observational cohort. The MOTHER RCT showed that early enteral tube feeding in addition to standard care did not affect symptoms/birth outcomes. Among RCT and cohort participants, we assessed how HG severity affected lipid, c-peptide, glucose and free thyroxine cord blood levels. HG severity measures were severity of vomiting at inclusion and 3 weeks after inclusion, pregnancy weight gain and 24-h energy intake at inclusion, readmissions and duration of hospital admissions. Cord blood measures were also compared between RCT participants allocated to enteral tube feeding and those receiving standard care. Between 2013-2016, 215 women were included: 115 RCT and 100 cohort participants. Eighty-one cord blood samples were available. Univariable not multivariable regression analysis showed that lower maternal weight gain was associated with higher cord blood glucose levels (β: -0·08, 95% CI -0·16, -0·00). Lower maternal weight gain was associated with higher Apo-B cord blood levels in multivariable regression analysis (β: -0·01, 95% CI -0·02, -0·01). No associations were found between other HG severity measures or allocation to enteral tube feeding and cord blood cardiometabolic markers. In conclusion, while lower maternal weight gain was associated with higher Apo-B cord blood levels, no other HG severity measures were linked with cord blood cardiometabolic markers, nor were these markers affected by enteral tube feeding.

Birth Weight and Early Postnatal Outcomes: Association with the Cord Blood Lipidome

Being born small or large for gestational age (SGA and LGA, respectively), combined with suboptimal early postnatal outcomes, can entail future metabolic alterations. The exact mechanisms underlying such risks are not fully understood. Lipids are a highly diverse class of molecules that perform multiple structural and metabolic functions. Dysregulation of lipid metabolism underlies the onset and progression of many disorders leading to pathological states. The aim of this pilot study was to investigate the relationships between birth weight, early postnatal outcomes, and cord blood serum lipidomes. We performed a non-targeted lipidomics-based approach to ascertain differences in cord blood lipid species among SGA, LGA, and appropriate-for-GA (AGA) newborns. Moreover, we longitudinally assessed (at birth and at ages of 4 and 12 months) weight and length, body composition (DXA), and clinical parameters. We disclosed distinct cord blood lipidome patterns in SGA, LGA, and AGA newborns; target lipid species distinctly modulated in each SGA, AGA, and LGA individual were associated with parameters related to growth and glucose homeostasis. The distinct lipidome patterns observed in SGA, AGA, and LGA newborns may play a role in adipose tissue remodeling and future metabolic risks. Maternal dietary interventions may potentially provide long-term benefits for the metabolic health of the offspring.

Relation between Maternal and Neonatal Serum Lipid Profile and Their Impact on Birth Weight

OBJECTIVE

Maternal malnutrition with disturbed lipid metabolism during pregnancy may affect the fetal lipid profile. We aimed to detect the relation between maternal and neonatal serum lipid profile, as well as to detect the serum lipid profile difference between small for gestational age (SGA) infants and appropriate for gestational age (AGA) infants to disclose the impact of maternal malnutrition on birth weight.

STUDY DESIGN

A cross-sectional study was conducted on 150 pregnant women coming to the labor room. Before delivery, maternal serum levels of high-density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides (TGs), and total cholesterol were assessed, then after delivery, cord blood samples were taken for assessment of the neonatal lipid profile. Birth weights were measured, then the neonates were divided into SGA and AGA groups.

RESULTS

Serum levels of LDL, TGs, and total cholesterol in the SGA infants were lower than that in the AGA infants. A positive correlation between maternal and neonatal serum TGs levels was found. Besides, there was a positive correlation between birth weight and maternal serum levels of LDL, TGs, and total cholesterol.

CONCLUSION

Maternal serum lipid profile could be an indicator of the neonatal serum lipid profile and birth weight.

KEY POINTS

· SGA neonates have lower levels of serum lipids compared to AGA neonates.. · There is a positive correlation between maternal and neonatal triglycerides.. · There is a positive correlation between birth weight and maternal serum lipids..

Matcha Green Tea Powder does not Prevent Diet-Induced Arteriosclerosis in New Zealand White Rabbits Due to Impaired Reverse Cholesterol Transport

INTRODUCTION

Green tea is associated with decreased risk for cardiovascular disease and stroke. Matcha is a special kind of powdered green tea known for its use in the Japanese tea ceremony. Due to its influence on lipoprotein parameters, it has been postulated to exert antiatherogenic effects. This study investigates whether it modulates the high-density lipoprotein (HDL) function and thereby influences the atherogenic process in an animal model with a strong influence on humans' situation.

METHODS AND RESULTS

After a pretreatment phase based on a standard diet, 10 female New Zealand White (NZW) rabbits are fed a high-fat diet for 20 weeks. The treatment group is additionally administered 1% matcha during the whole experiment. Long-term matcha treatment leads to lowered HDL cholesterol, impaired cholesterol transport manifested by reduced in vitro cholesterol efflux capacity, reduced cholesteryl ester transfer protein (CETP)-mediated cholesterol ester (CE) transfer between HDL and triglyceride-rich particles, and reduced macrophage-specific in vivo transfer, where ian increased absorption of cholesterol in the liver but a decreased secretion into bile is observed. Pulse wave velocity, assessed by nuclear magnetic resonance, is increased in matcha-treated animals, and a similar trend is observed for atherosclerotic lesion formation.

CONCLUSION

Long-term matcha green tea treatment of hypercholesterolemic rabbits cause impaired reverse cholesterol transport and increased vascular stiffness, and susceptibility for atherosclerotic lesion development.

Low CETP activity and unique composition of large VLDL and small HDL in women giving birth to small-for-gestational age infants

Cholesteryl ester transfer protein (CETP) regulates high density lipoproteins (HDL)-cholesterol (C) and HDL-C is essential for fetal development. We hypothesized that women giving birth to large-for-gestational-age (LGA) and small-for-gestational age (SGA) infants differed in longitudinal changes in lipoproteins, CETP activity and HDL-C and that placentas from women with higher or lower circulating HDL-C displayed differential expression of mRNAs involved in cholesterol/nutrient transport, insulin signaling, inflammation/ extracellular matrix (ECM) remodeling. Circulating lipids and CETP activity was measured during pregnancy, NMR lipidomics in late pregnancy, and associations with LGA and SGA infants investigated. RNA sequencing was performed in 28 placentas according to higher and lower maternal HDL-C levels. Lipidomics revealed high triglycerides in large VLDL and lipids/cholesterol/cholesteryl esters in small HDL in women giving birth to SGA infants. Placentas from women with higher HDL-C had decreased levels of CETP expression which was associated with mRNAs involved in cholesterol/nutrient transport, insulin signaling and inflammation/ECM remodeling. Both placental and circulating CETP levels were associated with growth of the fetus. Low circulating CETP activity at 36–38 weeks was associated with giving birth to SGA infants. Our findings suggest a link between increased maternal HDL-C levels, low CETP levels both in circulation and placenta, and SGA infants.

Increased risk for early hypertriglyceridemia in small for gestational age preterm infants

Small for gestational age preterm are at increased risk for future metabolic syndrome. Early indication for the disrupted metabolism may be found in the perinatal period. We aimed to evaluate whether small for gestational age preterm infants are at increased risk for hypertriglyceridemia when treated with lipid emulsions, and to investigate the association between triglyceride levels and morbidity. Small for gestational age infants ≤ 34 weeks' gestation age born during 2013-2016 were matched and compared with appropriate for gestational age counterparts. Triglyceride concentration > 250 mg/dL during treatment with parenteral nutrition was considered high. The study included 71 pairs of preterm infants. Hypertriglyceridemia was documented among 22.5% of the small for gestational age infants vs. 5.6% of the appropriate for gestational age infants (p = 0.007). Mean triglyceride levels were 194.4 ± 192.3 mg/dL and 99.9 ± 82.8 mg/dL, respectively (p < 0.001). Small for gestational age was predictive of hypertriglyceridemia (OR = 6.41; 95% CI 1.8-22.9). No significant association was found between triglyceride levels and morbidities in multivariate analysis.Conclusion: Small for gestational age preterm infants receiving lipid emulsions might be at a higher risk for hypertriglyceridemia. Routine monitoring of triglyceride levels will enable identification of the necessity for a slower increase in lipid emulsion therapy. What is Known: • Moderate and very preterm infants are routinely treated with lipid emulsions. • Small for gestational age (SGA) infants may have different metabolism, as they demonstrate higher risk for metabolic syndrome. What is New: • • SGA infants had a higher mean triglyceride level and more commonly had early hypertriglyceridemia (triglycerides > 250 mg/dL) compared with appropriate for gestational age infants treated with the same intravenous lipid dose. Small for gestational age was predictive of hypertriglyceridemia. • No significant association was found between triglyceride levels and morbidities in multivariate analysis.

Associations between maternal serum HDL-c concentrations during pregnancy and neonatal birth weight: a population-based cohort study

Background

To evaluate the associations between maternal serum concentrations of high-density lipoprotein cholesterol (HDL-c) throughout pregnancy and neonatal birth weight (BW) and small for gestational age (SGA) births.

Methods

A prospective cohort of 2241 pregnant women was followed from recruitment to delivery in three hospitals in Beijing, China between January 2014 and December 2017. Maternal fasting serum lipids concentrations were measured at gestational week 6–12, 16, 24 and 36. Major outcome was neonatal BW. The associations between maternal HDL-c and BW were estimated by linear regression and linear mixed-effects models. Odds ratios (ORs) and 95% confidence intervals of SGA births in relation to HDL-c were evaluated via logistic regression analysis.

Results

There was a tendency that mothers with higher HDL-c concentrations throughout gestation gave birth to infants with lower BW. A negative association was found between maternal HDL-c concentrations and BW at 24th and 36th gestational weeks (B = − 34.044, P = 0.034; B = − 53.528, P = 0.000). The HDL-c trend of change was inversely associated with BW (B = − 442.736, P = 0.000). Mothers with SGA neonates had higher serum HDL-c concentration at the 36th gestational week (P < 0.01). The incidences of SGA in the three groups (HDL-c: 1.84–2.23 mmol/L, 2.24–2.59 mmol/L and ≥ 2.60 mmol/L) were higher than the group with the lowest concentration of HDL-c (< 1.83 mmol/L) (P < 0.01, P < 0.01, P < 0.001) at 36th week. Higher maternal HDL-c concentrations at 36th week (HDL-c: 1.84–2.23 mmol/L, 2.24–2.59 mmol/L and ≥ 2.60 mmol/L) were positively associated with the incidence of SGA (OR = 1.900, P = 0.008; OR = 1.893, P = 0.008; OR = 1.975, P = 0.004). The HDL-c trend of change was positively associated with SGA births (OR = 9.772, P = 0.000).

Conclusions

Maternal serum HDL-c concentrations were inversely associated with BW at 24th and 36th gestational weeks. The high concentrations of HDL-c at the 36th gestational week increased the risk of SGA. The maternal HDL-c trend of change across pregnancy was associated with smaller neonatal size.

Maternal-fetal cholesterol transfer in human term pregnancies

OBJECTIVES

The extent to which the human term fetus utilizes cholesterol released from the placenta has remained elusive. Our aims were to estimate the net mass of cholesterol taken up by the uteroplacental unit, released by the placenta and taken up by the fetus. Thereby we aimed to explore the maternal-fetal cholesterol transfer and hypothesized that maternal levels and uteroplacental uptake were correlated to the fetal uptake of cholesterol.

METHODS

A cross-sectional in vivo study of 179 fasting, healthy women with uncomplicated singleton pregnancies. Blood flow in the uterine artery (n = 70) and umbilical vein (n = 125) was measured by Doppler ultrasound. Blood samples from the maternal radial artery, antecubital vein and uterine vein, and the umbilical artery and vein were obtained during cesarean section. Cholesterol was determined enzymatically.

RESULTS

We found a significant uteroplacental uptake (median [Q1,Q3]) of total (3.50 [-36.8,61.1]) and HDL cholesterol (6.69 [-3.78,17.9]) μmol/min, and a fetal uptake of HDL (8.07 [4.48,12.59]), LDL (5.97 [2.77,8.92]) and total cholesterol (13.2 [8.06,21.58]) μmol/min. Maternal cholesterol levels were not correlated to fetal uptake of cholesterol. There was a correlation between uteroplacental uptake of total (rho 0.35, p 0.003) and LDL cholesterol (rho 0.25, p 0.03) and the fetal uptake of LDL cholesterol from the umbilical circulation. The fetal uptake of cholesterol from HDL was higher than from LDL (p < 0.001).

CONCLUSION

Fetal cholesterol uptake is independent of maternal cholesterol levels, but related to the uteroplacental uptake of cholesterol from LDL. This suggests that the placenta influences maternal-fetal cholesterol transfer at term.

HDL cholesterol efflux capacity and cholesteryl ester transfer are associated with body mass, but are not changed by diet-induced weight loss: A randomized trial in abdominally obese men

BACKGROUND AND AIMS

Obesity is associated with a lower HDL-mediated cholesterol efflux from macrophages and a higher CETP (cholesteryl ester transfer protein) activity, but effects of weight loss are not clear. In addition, associations with visceral and subcutaneous adipose tissue are not known. We therefore investigated effects of diet-induced weight loss on HDL-mediated cholesterol efflux and cholesterol ester (CE) transfer in abdominally obese men. Differences between normal-weight and abdominally obese men were also examined.

METHODS

Twenty-five apparently healthy, normal-weight men (waist circumference: <94 cm) and 52 abdominally obese men (waist circumference: 102-110 cm) were included. Abdominally obese subjects were randomly allocated to a dietary weight-loss intervention group or a no-weight loss control group. Individuals from the intervention group followed a very-low-calorie diet for 6 weeks to obtain a waist circumference below 102 cm, followed by a 2-week weight-stable period. Cholesterol efflux was measured in BODIPY-labeled murine J774 macrophages. CE transfer was measured by quantifying the transfer of CE from radiolabeled exogenous HDL to apoB-containing lipoproteins.

RESULTS

Cholesterol efflux capacity was 9 percentage point (pp) lower in abdominally obese than in normal-weight men (p≤0.001), while CE transfer was 5 pp higher (p≤0.01). Diet-induced weight-loss of 10.3 kg did not change cholesterol efflux and CE transfer. In addition, stepwise regression analysis did not suggest that the different fat depots are differently related to efflux capacity and CE transfer.

CONCLUSIONS

After a 2-week weight-stable period, dietary weight loss of 10 kg did not improve ABCA1-mediated cholesterol efflux and CE transfer in abdominally obese men.

Cord and maternal sera from small neonates share dysfunctional lipoproteins with proatherogenic properties: Evidence for Barker's hypothesis

BACKGROUND

Fetal growth restriction (GR) is associated with perinatal mortality and subsequent metabolic disorders in adulthood. Until now, there is little information regarding changes in the properties of lipoproteins from growth-restricted fetuses and their maternal sera.

OBJECTIVE

To identify unique lipoprotein biomarkers for fetal GR in maternal and cord sera from small neonates, we analyzed lipoprotein compositions and functions.

METHODS

Lipoprotein compositions and functions were compared between cord blood and maternal blood among small for gestational age neonates (SGA; n = 15, 2589 ± 50 g) and appropriate for gestational age neonates (AGA; n = 15) in Korea.

RESULTS

Cord blood from the SGA group showed 2-fold higher triglyceride (TG) and TG/high-density lipoprotein cholesterol levels than the AGA group as well as significantly lower (up to 20%) paraoxonase activity and apolipoprotein (apo) A-I content. The SGA group showed the highest cholesteryl ester transfer protein activities in both cord and maternal sera. SGA neonates showed elevated apo-B content in very low-density lipoprotein, 52% reduction of apo A-I content in high-density lipoprotein, and 30% increased glycation (P < .001) compared with AGA neonates. Especially, low-density lipoprotein from the SGA group showed 1.9-fold higher sensitivity to oxidation as well as 3-fold greater uptake into macrophages, suggesting stronger proatherosclerotic properties. Lipoproteins from maternal serum of SGA neonates showed greater oxidation along with TG enrichment and loss of antioxidant ability. On microinjection of cord serum (50 nL) into zebrafish embryos, the SGA group showed the most severe embryonic damage.

CONCLUSIONS

Lipoproteins from cord and maternal sera of SGA neonates resulted in severe impairment of functional and structural correlations accompanied by greater pro-oxidant and proatherosclerotic properties.

Lipids and Adipokines in Cord Blood and at 72 h in Discordant Dichorionic Twins

BACKGROUND

Intrauterine growth restriction (IUGR) is a risk factor for developing metabolic syndrome later in life. We explored whether adipokine concentrations in cord blood (CB) and on day 3 (D3) were related to impaired fetal growth and lipids in IUGR twins.

PATIENTS AND METHODS

Thirty-six discordant (birth weight [BW] discordance ≥20% calculated in relation to the heavier co-twins) and 42 concordant (BW discordance ≤ 10%) twin pairs were included.

RESULTS

In IUGR twins, both adiponectin/BW and triglyceride (TG) levels were significantly higher, while total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol were lower in CB. On D3, both leptin and HDL-C levels were significantly lower and TG levels were significantly higher in IUGR twins. In the discordant group, the alterations in lipids were not related to any adipokine.

CONCLUSIONS

IUGR is related to lower leptin level and proatherogenic lipid profile (higher TG and lower HDL-C), which are not influenced by adipokine at birth.

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.

Circulating PCSK9 levels correlate with the serum LDL cholesterol level in newborn infants

BACKGROUND AND AIMS

Protein convertase subtilisin/Kexin type-9 (PCSK9) is a substantial player in lipoprotein metabolism. This study was designed to elucidate the role of PCSK9 in the regulation of lipoprotein during the fetal period.

STUDY DESIGN AND SUBJECTS

This study was a cross-sectional study. Eighty-one neonates (45 males, 36 females) who were admitted to the neonatal intensive care unit were enrolled in the study. The median age in gestational weeks and weight at birth were 37.1 weeks and 2493 g, respectively. There were no gender differences, but the proportion of infants who were small-for-gestational age (SGA) was significantly higher among females than males. The prefed serum PCSK9 level was assayed with ELISA kits.

RESULTS

The median PCSK9 concentration in male newborns was significantly lower than that in females (148.2 ng/ml vs. 171.4 ng/ml, respectively, p<0.001). Circulating serum PCSK9 levels were positively correlated with total cholesterol (r=0.281, p<0.05) and low-density lipoprotein cholesterol (LDL-C; r=0.272, p<0.05). However, there were no correlations between PCSK9 levels and birth weight, gestational age or SGA. Multivariate forward stepwise linear regression analysis revealed that gestational age and circulating PCSK9 levels were independent predictors of the serum LDL-C levels in newborn infants.

CONCLUSION

Our first quantitative analysis of neonatal serum PCSK9 levels at birth showed that circulating PCSK9 levels show gender-based differences and are significantly correlated with LDL-C. These results suggest that PCSK9 could play an important role in regulating LDL-C levels during the fetal period.

Insulin-like growth factor-1 and lipoprotein profile in cord blood of preterm small for gestational age infants

Low birth weight was associated with cardiometabolic diseases in adult age. Insulin-like growth factor-1 (IGF-1) has a crucial role in fetal growth and also associates with cardiometabolic risks in adults. Therefore, we elucidated the association between IGF-1 level and serum lipids in cord blood of preterm infants. The subjects were 41 consecutive, healthy preterm neonates (27 male, 14 female) born at <37-week gestational age, including 10 small for gestational age (SGA) infants (<10th percentile). IGF-1 levels and serum lipids were measured in cord blood, and high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC) and very low-density lipoprotein triglyceride (VLDLTG) levels were determined by HPLC method. SGA infants had lower IGF-1 (13.1 ± 5.3 ng/ml), total cholesterol (TC) (55.0 ± 14.8), LDLC (21.6 ± 8.3) and HDLC (26.3 ± 11.3) levels, and higher VLDLTG levels (19.0 ± 12.7 mg/dl) than in appropriate for gestational age (AGA) infants (53.6 ± 25.6, 83.4 ± 18.9, 36.6 ± 11.1, 38.5 ± 11.6, 8.1 ± 7.0, respectively). In simple regression analyses, log IGF-1 correlated positively with birth weight (r = 0.721, P < 0.001), TC (r = 0.636, P < 0.001), LDLC (r = 0.453, P = 0.006), and HDLC levels (r = 0.648, P < 0.001), and negatively with log TG (r = -0.484, P = 0.002) and log VLDL-TG (r = -0.393, P = 0.018). Multiple regression analyses demonstrated that IGF-1 was an independent predictor of TC, HDLC and TG levels after the gestational age and birth weight were taken into account. In preterm SGA infants, cord blood lipids profile altered with the concomitant decrease in IGF-1 level.

Metabolomic profile of umbilical cord blood plasma from early and late intrauterine growth restricted (IUGR) neonates with and without signs of brain vasodilation

Objectives

To characterize via NMR spectroscopy the full spectrum of metabolic changes in umbilical vein blood plasma of newborns diagnosed with different clinical forms of intrauterine growth restriction (IUGR).

Methods

23 early IUGR cases and matched 23 adequate-for-gestational-age (AGA) controls and 56 late IUGR cases with 56 matched AGAs were included in this study. Early IUGR was defined as a birth weight <10^th centile, abnormal umbilical artery (UA) Doppler and delivery <35 weeks. Late IUGR was defined as a birth weight <10^th centile with normal UA Doppler and delivery >35 weeks. This group was subdivided in 18 vasodilated (VD) and 38 non-VD late IUGR fetuses. All AGA patients had a birth weight >10^th centile. ¹H nuclear magnetic resonance (NMR) metabolomics of the blood samples collected from the umbilical vein at delivery was obtained. Multivariate statistical analysis identified several metabolites that allowed the discrimination between the different IUGR subgroups, and their comparative levels were quantified from the NMR data.

Results

The NMR-based analysis showed increased unsaturated lipids and VLDL levels in both early and late IUGR samples, decreased glucose and increased acetone levels in early IUGR. Non-significant trends for decreased glucose and increased acetone levels were present in late IUGR, which followed a severity gradient when the VD and non-VD subgroups were considered. Regarding amino acids and derivatives, early IUGR showed significantly increased glutamine and creatine levels, whereas the amounts of phenylalanine and tyrosine were decreased in early and late-VD IUGR samples. Valine and leucine were decreased in late IUGR samples. Choline levels were decreased in all clinical subforms of IUGR.

Conclusions

IUGR is not associated with a unique metabolic profile, but important changes are present in different clinical subsets used in research and clinical practice. These results may help in characterizing comprehensively specific alterations underlying different IUGR subsets.

Cord blood triglycerides are associated with IGF-I levels and contribute to the identification of growth-restricted neonates

OBJECTIVE

The aim of this study was to investigate whether readily available laboratory tests may aid in the identification of growth-restricted neonates.

DESIGN

Cord serum levels of 15 chemical analytes, including insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 3 (IGFBP-3) were measured in newborns ≥36 weeks gestational age (GA). Based on the number of anthropometric indices (out of four) with values ≤25th centile for GA, the babies were allocated into three groups, i.e., Group(25)0, Group(25)1 and Group(25)2 corresponding to neonates with 0, 1 and 2 or more indices, respectively, that were ≤25th centile for GA. Furthermore, two composite variables were developed: A25 (Group(25)0 and Group(25)1) and B25 (Group(25)0 and Group(25)2). The data were evaluated by the Mann-Whitney test and multiple regression analyses.

RESULTS

Cord serum triglycerides and total cholesterol levels were significantly higher in Group(25)2 compared to Group(25)0 (p values 0.004 and 0.0009, respectively). The triglycerides almost doubled the power of the variable B25 for predicting IGF-I levels and were found to have a highly significant, negative association with the IGF-I levels (p<0.0001). The IGF-I along with the IGFBP-3 levels explained almost one third of the variation of triglycerides.

CONCLUSION

Cord serum triglycerides can assist in the identification of growth-restricted neonates. The novel finding of the association of triglycerides with IGF-I calls for further research as this can illuminate unknown aspects of the fetal lipid metabolism.

Placental transport in pregnancy pathologies

The placenta is positioned between the maternal and fetal circulation and hence plays a key role in transporting maternal nutrients to the developing fetus. Fetal growth changes in the 2 most frequent pregnancy pathologies, gestational diabetes mellitus and fetal growth restriction, are predominantly characterized by an exaggerated and restricted fat accretion, respectively. Glucose, by its regulating effect on fetal insulin concentrations, and lipids have been strongly implicated in fetal fat deposition. Transplacental glucose flux is highly efficient and limited only by nutrient availability (flow-limited)--ie, driven by the maternal-fetal glucose concentration gradient and blood flow, with little, if any, effect of placental morphology, glucose consumption, and transporter expression. This explains why, despite changes in these determinants in both pathologies, transplacental glucose flux is unaltered.

Changes in the metabolic footprint of placental explant-conditioned medium cultured in different oxygen tensions from placentas of small for gestational age and normal pregnancies

Being born small for gestational age (SGA) confers significantly increased risks of perinatal morbidity and mortality. Accumulating evidence suggests that an SGA fetus results from a poorly perfused and abnormally developed placenta. Some of the placental features seen in SGA, such as abnormal cell turnover and impaired nutrient transport, can be reproduced by culture of placental explants in hypoxic conditions. Metabolic footprinting offers a hypothesis-generating strategy to investigate factors absorbed by and released from this tissue in vitro. Previously, metabolic footprinting of the conditioned culture media has identified differences in placental explants cultured under normoxic and hypoxic conditions and between normal pregnancies and those complicated by pre-eclampsia. In this study we aimed to examine the differences in the metabolic footprint of placental villous explants cultured at different oxygen (O(2)) tensions between women who deliver an SGA baby (n = 9) and those from normal controls (n = 8). Placental villous explants from cases and controls were cultured for 96 h in 1% (hypoxic), 6% (normoxic) and 20% (hyperoxic) O(2). Metabolic footprints were analysed by Ultra Performance Liquid Chromatography coupled to an electrospray hybrid LTQ-Orbitrap Mass Spectrometry (UPLC-MS). 574 metabolite features showed significant difference between SGA and normal at one or more of the oxygen tensions. SGA explant media cultured under hypoxic conditions was observed, on a univariate level, to exhibit the same metabolic signature as controls cultured under normoxic conditions in 49% of the metabolites of interest, suggesting that SGA tissue is acclimatised to hypoxic conditions in vivo. No such behaviour was observed under hyperoxic culture conditions. Glycerophospholipid and tryptophan metabolism were highlighted as areas of particular interest.

Association between serum adipocytokine and cholesterol levels in cord blood

BACKGROUND

Serum leptin and adiponectin levels are strongly associated with lipid metabolism in adults. These adipocytokines play a role in intrauterine and postnatal growth but the association between cord blood levels of these adipocytokines and cholesterol at birth remains unclear.

METHODS

The study involved 52 appropriate-for-gestational-age (AGA) infants (25 male, 27 female, 37-41 weeks of gestational age) born at Keiai Hospital without any maternal complications. Cord blood concentrations of leptin, total adiponectin, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), other neonatal characteristics, and maternal factors were assessed to investigate the association between cord blood leptin or adiponectin levels and cholesterol levels.

RESULTS

Cord blood leptin levels were significantly higher in girls. Simple regression analysis indicated that cord blood leptin levels were significantly associated with birthweight, gestational age, birthweight SD score, body mass index (BMI), ponderal index, LDL-C, and TC; but total adiponectin levels were not significantly associated with any neonatal characteristics or maternal factors. A multiple regression analysis indicated that cord leptin levels were significantly associated with BMI (beta= 0.407, P= 0.001), LDL-C (beta=-0.345, P= 0.004), and infant's gender (beta=-0.332, P= 0.006); adiponectin levels were significantly associated with only gestational age (beta= 0.279, P= 0.047).

CONCLUSION

Cord leptin level is significantly associated with cord cholesterol level at birth, anthropometry, and infant gender. The present study suggests that cord blood leptin may be a key hormone for controlling fetal lipid metabolism.

Cord blood lipid profile and associated factors: baseline data of a birth cohort study

The cord blood lipid profile may be associated with lifelong changes in the metabolic functions of the individual. The aim of the present study was for the first time in Iran to assess the cord blood lipid profile of neonates, as well as some of its environmental influencing factors. The subjects were 442 (218 boys and 224 girls) normal vaginal delivery newborns. Overall, 14.4% of neonates were preterm and the rest were full-term. In total, 9.2% (n = 35) of the full-term newborns were small-for-gestational-age (SGA), of which 16 had a ponderal index (PI) below the 10th percentile (SGA I) and 19 had a PI above the 10th percentile (SGA II), 5.5% (n = 21) were large-for-gestational-age (LGA), and the remainder were appropriate-for-gestational-age (AGA).Before becoming pregnant, 6.9% of mothers were underweight, 49.3% had normal body mass index (BMI), 39.4% were overweight and 4.4% were obese. Total and high-density lipoprotein cholesterol (HDL-C) in girls were significantly higher than in boys (80.3 +/- 33.3 and 31.1 +/- 9.9 vs. 73.3 +/- 23.1 and 28.8 +/- 8.7 mg/dL, respectively, P < 0.05). The mean apolipoprotein A (apoA) of neonates with underweight mothers was significantly lower, and the mean apoB level of those with overweight mothers was significantly higher than other neonates. The mean low-density lipoprotein cholesterol (LDL-C), HDL-C and apoA of the LGA newborns were significantly lower, and their apoB was significantly higher compared with AGA and SGA neonates. The SGA I neonates had significantly lower total cholesterol, LDL-C, HDL-C and apoA, as well as higher triglycerides, lipoprotein a and apoB than the SGA II group. The mean cord blood triglycerides of full-term neonates was significantly higher than preterm neonates (69.4 +/- 11.9 vs. 61.4 +/- 12.7 mg/dL, respectively, P = 0.04). A preconception maternal BMI of > or =25 kg/m(2) correlated significantly with the cord triglycerides (OR = 1.3, [95% CI 1.07, 1.5]) and with apoB (OR = 1.4, [95% CI 1.1, 1.5]). The BMI <18 of mothers before pregnancy correlated with low HDL-C (OR = 1.3, [95% CI 1.04, 1.7]). Birthweight correlated with high cord triglyceride level (SGA: OR = 1.4, [95% CI 1.1, 1.7]; LGA: OR = 1.6, [95% CI 1.3, 1.7] compared with AGA). These associations remained significant even after adjusting for the preconception BMI of mothers. Our findings reflect the possible interaction of environmental factors and fetal growth and the in utero lipid metabolism. Long-term longitudinal studies in different ethnicities would help to elucidate the relationship.

Serum carnitine, triglyceride and cholesterol profiles in Korean neonates

This study evaluated carnitine and lipid status of fifty Korean newborns. Each subject was assigned to two groups: one according to body weight at birth and the other according to gestational age. Serum total, HDL- and LDL-cholesterol were significantly lower and triacylglycerols were significantly higher, by 14 %, in the low birth weight infant (LBWI, 1310–2490 g) group compared with the normal birth weight infant (NBWI, 2570–4420 g) group. Neither birth weight nor gestational age affected serum total carnitine concentrations. However, serum ASAC (acid-soluble acylcarnitine) concentrations were 43 % higher (P < 0·001) in the LBWI group compared with the NBWI group, and approximately twice as high (P < 0·05) in the 28–32 gestational age group compared with the other gestational age groups. NEC (non-esterified acyl carnitine) fractions were significantly higher in the NBWI and 28–32 week groups (P < 0·001 andP < 0·05); consequently serum acyl/NEC carnitine ratios were four times higher in the LBWI group compared with the NBWI group and 2–3 times higher in the 25–32 week age group compared with the more advanced gestational age groups. Urinary carnitine excretion, including the NEC fraction and total carnitine, was significantly higher (P < 0·001) for LBWI than for NBWI. By gestational age, NEC excretion of the 28–32 week group was significantly (P < 0·05) higher than that of the other two groups, but total carnitine excretion was not different among the groups. This study demonstrated that Korean immature and preterm newborns have higher serum triacylglycerol concentrations but lower carnitine status than NBWI. Therefore, the lower carnitine status and moderately higher triacylglycerols may suggest that LBWI in Korea might be at risk for poor carnitine status and decreased capacity to utilise fatty acids for energy.

Aspirin regulates expression and function of scavenger receptor‐BI in macrophages: studies in primary human macrophages and in mice

Scavenger receptor class B type I (SR-BI) has been shown to be expressed in human atherosclerotic plaque macrophages, where it is believed to reduce atherosclerosis by promoting cholesterol efflux. In this study we investigated the influence of aspirin and other NSAIDs on SR-BI expression and function in cultured human macrophages as well as in different mouse strains. Incubation of human macrophages with 0.5 mmol/l aspirin resulted in increased SR-BI protein expression and increased uptake of HDL-associated [3H]cholesteryl oleate without changes of SR-BI mRNA levels. In contrast, using 5 mmol/l of aspirin, SR-BI expression and function were significantly decreased. Sodium salicylate exerted similar effects on SR-BI expression, whereas no effects were observed using known COX1/2 inhibitors ibuprofen and naproxen, respectively. In in vivo studies low-dose aspirin treatment (6 mg/kg.day) induced SR-BI expression in wild-type and PPAR-alpha knockout mice, respectively, whereas the opposite effect was observed upon high-dose aspirin treatment (60 mg/kg.day) in these animals. We could show that COX-independent effects of aspirin were able to enhance expression of SR-BI in macrophages in a post-transcriptional, PPAR-alpha independent way, suggesting a novel pharmacologic effect of aspirin.

Increased plasma levels of LDL cholesterol in rabbits after adenoviral overexpression of human scavenger receptor class B type I

Scavenger receptor class B type I (SR-BI), a CD36 family member, plays a key role in high-density lipoprotein (HDL) metabolism, reverse cholesterol transport, and whole body cholesterol homeostasis, and is shown to be involved in the development of atherosclerosis in mice. In this report, we describe the effects of the adenoviral overexpression of human SR-BI (hSR-BI) in New Zealand White (NZW) rabbits, a wild-type animal model that expresses cholesteryl ester transfer protein (CETP) in plasma, displays a manlike lipoprotein profile, and is susceptible to atherosclerosis. A total of 1x10(12) adenoviral particles containing either hSR-BI or lacZ complementary deoxyribonucleic acid (control) were infused into the ear vein of NZW rabbits. Transgene expression was ascertained by TaqMan Real Time polymerase chain reaction measurements. Rabbits infected with Ad/hSR-BI (adenoviral plasmids containing hSR-BI) showed a faster clearance of administered [3H]HDL cholesterol and significantly decreased apolipoprotein (apo) A-I levels when compared to control rabbits, respectively. Interestingly, we found markedly increased levels of low-density lipoprotein (LDL) cholesterol exclusively in SR-BI-overexpressing rabbits. These changes were not accompanied by alterations in LDL receptor expression but by increased levels of CE transfer in these animals. By lowering HDL cholesterol and increasing plasma apoB-containing lipoprotein levels, the overexpression of SR-BI leads to a lipoprotein pattern, which is believed to enhance the development of atherosclerosis. The role of SR-BI in lipoprotein metabolism and atherogenesis in rabbits--a CETP-expressing animal model displaying a manlike lipoprotein profile--may therefore be different from the one found in rodents.

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.

Fetal cord plasma lipoprotein status in uncomplicated human pregnancies and in pregnancies complicated by pre-eclampsia and intrauterine growth restriction

Maternal lipids have been studied extensively in pre-eclampsia (PE) and intrauterine growth restriction (IUGR) but little is known about fetal lipids. We hypothesised that the maternal lipid perturbations in PE and IUGR pregnancies would result in similar alterations in the fetal lipid profile. We performed a cross-sectional case control study of maternal and fetal (delivery venous cord blood) lipid and lipoprotein concentrations in third trimester uncomplicated pregnancies (n = 81) and in pregnancies complicated by PE (n = 23) or IUGR (n = 17). In uncomplicated pregnancies, fetal log total cholesterol (TC), log triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) levels were significantly affected by mode of delivery. Fetal log TC (r = 0.37, P = 0.02), log TG (r = 0.34, P = 0.04) and TC/HDL-C ratio (r = 0.31, P = 0.05) were positively correlated with placental weight. Maternal TC (r = 0.35, P = 0.03) and LDL levels (r = 0.36, P = 0.02) were associated with fetal HDL-C levels. Maternal TC was significantly elevated in PE [mean 6.75 (standard deviation 1.14) mmol/L] compared to BMI-matched controls [5.94 (0.89) mmol/L P = 0.04]. In PE, fetal log TC [mean 0.36 (0.23) versus 0.11 (0.15) log mmol/L, P = 0.03], fetal log TG [-0.21 (0.32) versus -0.49 (0.26) log mmol/L, P = 0.02] and fetal TC/HDL-C ratio [3.64 (1.62) versus 1.80 (0.86), P = 0.001] were higher than in controls, after adjustment for mode of delivery. In IUGR, fetal log TG [-0.17 (0.35) versus -0.57 (0.10) log mmol/L, P = 0.01] was higher than controls, after adjustment for mode of delivery. There were no correlations between maternal and fetal lipid levels, or between fetal birth weight and either maternal or fetal lipids in the PE or IUGR groups. We conclude that although fetal lipids do not show a direct correlation with maternal lipids in PE or IUGR, these complications of pregnancy significantly impact upon fetal lipid levels possibly due to increased fetal stress or compromised placental lipid transport. Our findings are potentially pertinent to understanding the future cardiovascular health of the offspring.

Molecular characterization of rabbit scavenger receptor class B types I and II: portal to central vein gradient of expression in the liver

To further elucidate the role of scavenger receptor class B type I (SR-BI) in reverse cholesterol transport and in atherogenesis, we performed studies in the rabbit, an animal model displaying a lipoprotein profile similar to that of human, expressing cholesteryl ester transfer protein in plasma and having been demonstrated to be susceptible to atherosclerosis. In this report, we describe for the first time the isolation and characterization of rabbit cDNA fragments encoding SR-BI and scavenger receptor class B type II (SR-BII). Development of an isoform-specific Taqman Real Time PCR system and generation of isoform-specific polyclonal antibodies allowed us to measure SR-BI and SR-BII expression in various rabbit organs on mRNA and protein levels, respectively. We found the highest expression of SR-BI in adrenal gland, liver, and proximal intestine; lesser expression was found in appendix and spleen. Immunohistochemical staining of frozen sections showed SR-BI expression in the cortex but not in the medulla of adrenal gland. An increasing portal to central vein gradient of expression was found within the hepatic lobule. As shown in this report, identification and characterization of SR-BI expression in the rabbit affords a powerful tool to elucidate the role of SR-BI in cholesterol homeostasis and atherogenesis in human.

Phospholipid and cholesteryl ester transfer are increased in lipoprotein lipase deficiency

OBJECTIVES

Phospholipid transfer protein (PLTP) and cholesteryl ester transfer protein (CETP) are key enzymes in lipoprotein metabolism by mediating the transfer and exchange of phospholipids (PL) and neutral lipids between lipoproteins. Lipoprotein lipase (LPL) deficiency is associated with low HDL-cholesterol (HDL-C) levels in both, the homozygous and heterozygous state. In the present study we set out to investigate the role of lipid transfer proteins, which are known to strongly determine HDL-C levels, in LPL deficiency.

DESIGN/SUBJECTS

Phospholipid acceptor and donor properties of lipoproteins, PLTP activity, CETP mass, activity and cholesteryl ester (CE) transfer were determined in two homozygous and six heterozygous LPL-deficient subjects and in 10 healthy, normolipidaemic controls, respectively.

RESULTS

The HDL isolated from LPL-deficient subjects showed strongly increased PL-acceptance when compared with controls (homozygotes versus heterozygotes versus control: 26.46 +/- 15.26 vs. 3.41 +/- 1.61 vs. 1.89 +/- 0.33 micromol mL-1 h-1/micromol mL-1 PL; all P < 0.05). Phospholipid transfer from apolipoprotein B containing lipoproteins was increased in heterozygotes when compared with controls (46.66 +/- 23.3 vs. 28.91 +/- 18.05 micromol mL-1 h-1/micromol mL-1 PL, P = 0.05). PLTP activity, however, was similar in LPL-deficient subjects and controls. CETP mass was highest in homozygotes, whilst enzyme activity was similar in LPL-deficient subjects and controls. CE transfer was highest in homozygotes (72.5 +/- 8.8%) and lowest in controls (28.7 +/- 5.2%, P < 0.01).

CONCLUSIONS

In conclusion, PL and CE transfer are increased in LPL deficiency and thus, partly explain low HDL-levels in LPL-deficient subjects. Enhanced transfer seems rather to be the result of altered lipoprotein composition and concentration than altered enzyme activity. Our findings on mechanisms leading to low HDL-C levels might show another aspect in atherogenesis in LPL deficiency.

Relationship between cholesteryl ester transfer protein and atherogenic lipoprotein profile in morbidly obese women

OBJECTIVE

Obesity is associated with increased morbidity and mortality from atherosclerotic disease. Lipid abnormalities contribute to the increased relative risk in obese subjects. Cholesteryl ester transfer protein (CETP) mass is increased in these patients and might mediate the atherogenic lipoprotein pattern observed in obesity.

METHODS AND RESULTS

Twenty-one morbidly obese, middle-aged, female subjects participated in this prospective study. Subjects were examined before and 1 year after surgical treatment. Fat mass was determined by body impedance analysis; CETP mass, by ELISA; CETP activity, by exogenous substrate assay; and LDL particle diameter, by gradient gel electrophoresis. Mean weight loss after 1 year was 28.7 kg; mean fat mass loss was 22.6 kg. Mean CETP mass decreased from 1.81 to 1.32 microg/mL (P=0.008); mean CETP activity decreased from 244 to 184 nmol x mL(-1) x h(-1) (P=0.004); and in parallel, the mean diameter of LDL particles increased (256.8 to 258.4 A, P=0.04).

CONCLUSIONS

We conclude that weight loss is associated with a pronounced decrease in CETP mass and activity and a consistent increase in LDL particle diameter. After 1 year of this prospective study in morbidly obese subjects undergoing weight loss by surgical treatment, it has been determined that some features of the atherogenic lipoprotein profile can be reversed.