Maternal cholesterol levels during gestation: boon or bane for the offspring?

Maternal Dietary Cholesterol and Egg Intake during Pregnancy and Large-for-Gestational-Age Infants: A Prospective Cohort Study

BACKGROUND

Cholesterol plays a vital role in fetal growth and development during pregnancy. There remains controversy over whether pregnant females should limit their cholesterol intake.

OBJECTIVES

The objective of this study was to investigate the association between maternal dietary cholesterol intake during pregnancy and infant birth weight in a Chinese prospective cohort study.

METHODS

A total of 4146 mother-child pairs were included based on the Jiangsu Birth Cohort study. Maternal dietary information was assessed with a semiquantitative food-frequency questionnaire. Birth weight z-scores and large-for-gestational-age (LGA) infants were converted by the INTERGROWTH-21st neonatal weight-for-gestational-age standard. Poisson regression and generalized estimating equations were employed to examine the relationships between LGA and maternal dietary cholesterol across the entire pregnancy and trimester-specific cholesterol intake, respectively.

RESULTS

The median intake of maternal total dietary cholesterol during the entire pregnancy was 671.06 mg/d, with eggs being the main source. Maternal total dietary cholesterol and egg-sourced cholesterol were associated with an increase in birth weight z-score, with per standard deviation increase in maternal total and egg-sourced dietary cholesterol being associated with an increase of 0.16 [95% confidence interval (CI): 0.07, 0.25] and 0.06 (95% CI: 0.03, 0.09) in birth weight z-score, respectively. Egg-derived cholesterol intake in the first and third trimesters was positively linked to LGA, with an adjusted relative risk of 1.11 (95% CI: 1.04, 1.18) and 1.09 (95% CI: 1.00, 1.18). Compared with mothers consuming ≤7 eggs/wk in the third trimester, the adjusted relative risk for having an LGA newborn was 1.37 (95% CI: 1.09, 1.72) for consuming 8-10 eggs/wk and 1.45 (95% CI: 1.12, 1.86) for consuming >10 eggs/wk (P-trend = 0.015).

CONCLUSIONS

Maternal total dietary cholesterol intake, as well as consuming over 7 eggs/wk during pregnancy, displayed significant positive relationships with the incidence of LGA, suggesting that mothers should avoid excessive cholesterol intake during pregnancy to prevent adverse birth outcomes.

Maternal high-calorie diet feeding programs hepatic cholesterol metabolism and Abca1 promoter methylation in the early life of offspring

Maternal high-calorie diet feeding can dramatically increase the susceptibility of metabolic diseases in offspring. However, whether maternal high-calorie diet feeding can program hepatic cholesterol metabolism in the early life of offspring is less understood, and the epigenetic mechanisms underlying this intergenerational effect, especially during the early life of offspring, are unknown. Female C57BL/6J mice were randomly assigned to a high-calorie diet or control diet before and during gestation, and lactation. Lipid metabolism was evaluated in male offspring at weaning. Gene expressions and quantitative methylation levels of key genes associated with hepatic cholesterol metabolism were further evaluated in offspring at weaning age. We found that maternal high-calorie diet feeding resulted in higher body weight, hypercholesterolemia, elevated total cholesterol in liver homogenates, and fat deposits in the liver in offspring at weaning. For key genes that regulate cholesterol metabolism in liver, we showed lower Hmgcr and Ldlr, and higher Abca1 mRNA and protein expressions in offspring from dams fed with high-calorie diet at weaning age. We further found that maternal high-calorie diet feeding significantly decreased Abca1 methylation level in offspring, with lower methylation levels of both CpG 11 and CpG 22 sites. Interestingly, we found that Abca1 methylation level was negatively associated with hepatic Abca1 mRNA expression in offspring from dams fed with high-calorie diet and controls. However, the expressions of key genes associated with hepatic cholesterol metabolism were not significant between fetuses of dams fed with high-calorie diet and control diet. In conclusion, our results indicate that maternal high-calorie diet feeding results in aberrant lipid metabolism, including hypercholesterolemia and fat deposits in the liver of offspring as early as weaning age. Furthermore, maternal high-calorie feeding can program hepatic cholesterol metabolism and Abca1 methylation in the early life of offspring.

Significance of lipids, lipoproteins, and apolipoproteins during the first 14-16 months of life

BACKGROUND AND AIMS

The aims of this study were to investigate lipid parameters during the first 14-16 months of life, to identify influential factors, and to test whether high concentrations at birth predict high concentrations at 2- and 14-16 months.

METHODS

The Copenhagen Baby Heart Study, including 13,354 umbilical cord blood samples and parallel venous blood samples from children and parents at birth (n = 444), 2 months (n = 364), and 14-16 months (n = 168), was used.

RESULTS

Concentrations of lipids, lipoproteins, and apolipoproteins in umbilical cord blood samples correlated highly with venous blood samples from newborns. Concentrations of low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (HDL) cholesterol, apolipoprotein B, and lipoprotein(a) increased stepwise from birth to 2 months to 14-16 months. Linear mixed models showed that concentrations of LDL cholesterol, non-HDL cholesterol, and lipoprotein(a) above the 80th percentile at birth were associated with significantly higher concentrations at 2 and 14-16 months. Finally, lipid concentrations differed according to sex, gestational age, birth weight, breastfeeding, and parental lipid concentrations.

CONCLUSIONS

Lipid parameters changed during the first 14-16 months of life, and sex, gestational age, birth weight, breastfeeding, and high parental concentrations influenced concentrations. Children with high concentrations of atherogenic lipid traits at birth had higher concentrations at 2 and 14-16 months. These findings increase our knowledge of how lipid traits develop over the first 14-16 months of life and may help in deciding the optimal child age for universal familial hypercholesterolaemia screening.

Pregnancy as an Early Cardiovascular Moment: Peripartum Cardiovascular Health

Pregnancy is commonly referred to as a window into future CVH (cardiovascular health). During pregnancy, physiological adaptations occur to promote the optimal growth and development of the fetus. However, in approximately 20% of pregnant individuals, these perturbations result in cardiovascular and metabolic complications, which include hypertensive disorders of pregnancy, gestational diabetes, preterm birth, and small-for-gestational age infant. The biological processes that lead to adverse pregnancy outcomes begin before pregnancy with higher risk of adverse pregnancy outcomes observed among those with poor prepregnancy CVH. Individuals who experience adverse pregnancy outcomes are also at higher risk of subsequent development of cardiovascular disease, which is largely explained by the interim development of traditional risk factors, such as hypertension and diabetes. Therefore, the peripartum period, which includes the period before (prepregnancy), during, and after pregnancy (postpartum), represents an early cardiovascular moment or window of opportunity when CVH should be measured, monitored, and modified (if needed). However, it remains unclear whether adverse pregnancy outcomes reflect latent risk for cardiovascular disease that is unmasked in pregnancy or if adverse pregnancy outcomes are themselves an independent and causal risk factor for future cardiovascular disease. Understanding the pathophysiologic mechanisms and pathways linking prepregnancy CVH, adverse pregnancy outcomes, and cardiovascular disease are necessary to develop strategies tailored for each stage in the peripartum period. Emerging evidence suggests the utility of subclinical cardiovascular disease screening with biomarkers (eg, natriuretic peptides) or imaging (eg, computed tomography for coronary artery calcium or echocardiography for adverse cardiac remodeling) to identify risk-enriched postpartum populations and target for more intensive strategies with health behavior interventions or pharmacological treatments. However, evidence-based guidelines focused on adults with a history of adverse pregnancy outcomes are needed to prioritize the prevention of cardiovascular disease during the reproductive years and beyond.

Effects of Gestational Diabetes Mellitus on Cholesterol Metabolism in Women with High-Risk Pregnancies: Possible Implications for Neonatal Outcome

Metabolic disorders in pregnancy, particularly gestational diabetes mellitus (GDM), are associated with an increased risk for adverse pregnancy outcome and long-term cardiometabolic health of mother and child. This study analyzed changes of serum cholesterol synthesis and absorption markers during the course of high-risk pregnancies, with respect to the development of GDM. Possible associations of maternal lipid biomarkers with neonatal characteristics were also investigated. The study included 63 women with high risk for development of pregnancy complications. Size and proportions of small low-density (LDL) and high-density lipoprotein (HDL) particles were assessed across trimesters (T1−T3), as well as concentrations of cholesterol synthesis (lathosterol, desmosterol) and absorption markers (campesterol, β-sitosterol). During the study, 15 women developed GDM, while 48 had no complications (non-GDM). As compared to the non-GDM group, women with GDM had significantly higher triglycerides in each trimester, while having a lower HDL-C level in T3. In addition, they had significantly lower levels of β-sitosterol in T3 (p < 0.05). Cholesterol synthesis markers increased across trimesters in both groups. A decrease in serum β-sitosterol levels during the course of pregnancies affected by GDM was observed. The prevalence of small-sized HDL decreased in non-GDM, while in the GDM group remained unchanged across trimesters. Newborn’s size in the non-GDM group was significantly higher (p < 0.01) and inversely associated with proportions of both small, dense LDL and HDL particles (p < 0.05) in maternal plasma in T1. In conclusion, high-risk pregnancies affected by GDM are characterized by altered cholesterol absorption and HDL maturation. Advanced lipid testing may indicate disturbed lipid homeostasis in GDM.

Maternal high cholesterol diet negatively programs offspring bone development and downregulates hedgehog signaling in osteoblasts

Cholesterol is one of the essential intrauterine factors required for fetal growth and development. Maternal high cholesterol levels are known to be detrimental for offspring health. However, its long-term effect on offspring skeletal development remains to be elucidated. We performed our studies in two strains of mice (C57BL6/J and Swiss Albino) and human subjects (65 mother–female newborn dyads) to understand the regulation of offspring skeletal growth by maternal high cholesterol. We found that mice offspring from high-cholesterol-fed dams had low birth weight, smaller body length, and delayed skeletal ossification at the E18.5 embryonic stage. Moreover, we observed that the offspring did not recover from the reduced skeletal mass and exhibited a low bone mass phenotype throughout their life. We attributed this effect to reduced osteoblast cell activity with a concomitant increase in the osteoclast cell population. Our investigation of the molecular mechanism revealed that offspring from high-cholesterol-fed dams had a decrease in the expression of ligands and proteins involved in hedgehog signaling. Further, our cross-sectional study of human subjects showed a significant inverse correlation between maternal blood cholesterol levels and cord blood bone formation markers. Moreover, the bone formation markers were significantly lower in the female newborns of hypercholesterolemic mothers compared with mothers with normal cholesterolemic levels. Together, our results suggest that maternal high cholesterol levels deleteriously program offspring bone mass and bone quality and downregulate the hedgehog signaling pathway in their osteoblasts.

Baseline Complete Blood Count and Chemistry Panel Profile from the Japan Environment and Children's Study (JECS)

BACKGROUND

The Japan Environment and Children's Study (JECS) is a nationwide birth cohort study of environmental factors affecting children's health and development. We summarize the complete blood count and chemistry panel statistical data from pregnant women enrolled in JECS.

METHODS

Statistical data of up to 58,056 mother's sample in their first (gestational age ≤ 13 weeks) and second trimester (22-27 weeks) were calculated.

RESULTS

Mean (SD) values in the first trimester were: white blood cell count, 7866 (1906)/μL; red blood cell count, 417 (33) 10⁴/μL; hemoglobin, 12.4 (1.0) g/dL; hematocrit, 37.1 (2.6)%; mean corpuscular volume, 89.2 (4.7) fL; mean corpuscular hemoglobin, 29.8 (1.9) pg; mean corpuscular hemoglobin concentration, 33.3 (0.9)%; platelet count, 24.8 (5.2) 10⁴/μL; HbA1c, 5.26 (0.26)%; total cholesterol, 181 (28) mg/dL; low density lipoprotein cholesterol, 95 (23) mg/dL; high density lipoprotein cholesterol, 73 (13) mg/dL; free cholesterol, 41 (7) mg/dL; triglycerides, 109 (47) mg/dL; total protein, 6.9 (0.4) g/dL; and albumin, 4.1 (0.2) g/dL. Mean values (SD) in the second trimester were: total cholesterol, 246 (38) mg/dL; free cholesterol, 61 (9) mg/dL; triglycerides, 183 (70) mg/dL; total protein, 6.5 (0.4) g/dL; and albumin, 3.6 (0.2) g/dL.

CONCLUSIONS

These data will be useful for future JECS studies.

Fetal High-Density Lipoproteins: Current Knowledge on Particle Metabolism, Composition and Function in Health and Disease

Cholesterol and other lipids carried by lipoproteins play an indispensable role in fetal development. Recent evidence suggests that maternally derived high-density lipoprotein (HDL) differs from fetal HDL with respect to its proteome, size, and function. Compared to the HDL of adults, fetal HDL is the major carrier of cholesterol and has a unique composition that implies other physiological functions. Fetal HDL is enriched in apolipoprotein E, which binds with high affinity to the low-density lipoprotein receptor. Thus, it appears that a primary function of fetal HDL is the transport of cholesterol to tissues as is accomplished by low-density lipoproteins in adults. The fetal HDL-associated bioactive sphingolipid sphingosine-1-phosphate shows strong vasoprotective effects at the fetoplacental vasculature. Moreover, lipoprotein-associated phospholipase A2 carried by fetal-HDL exerts anti-oxidative and athero-protective functions on the fetoplacental endothelium. Notably, the mass and activity of HDL-associated paraoxonase 1 are about 5-fold lower in the fetus, accompanied by an attenuation of anti-oxidative activity of fetal HDL. Cholesteryl ester transfer protein activity is reduced in fetal circulation despite similar amounts of the enzyme in maternal and fetal serum. This review summarizes the current knowledge on fetal HDL as a potential vasoprotective lipoprotein during fetal development. We also provide an overview of whether and how the protective functionalities of HDL are impaired in pregnancy-related syndromes such as pre-eclampsia or gestational diabetes mellitus.