Aortic intima-media thickness, serum IGF-I, IGFBP-3, and leptin levels in intrauterine growth-restricted newborns of healthy mothers

Adipokines in pregnancy

Reproductive success consists of a sequential events chronology, starting with the ovum fertilization, implantation of the embryo, placentation, and cellular processes like proliferation, apoptosis, angiogenesis, endocrinology, or metabolic changes, which taken together finally conduct the birth of healthy offspring. Currently, many factors are known that affect the regulation and proper maintenance of pregnancy in humans, domestic animals, or rodents. Among the determinants of reproductive success should be distinguished: the maternal microenvironment, genes, and proteins as well as numerous pregnancy hormones that regulate the most important processes and ensure organism homeostasis. It is well known that white adipose tissue, as the largest endocrine gland in our body, participates in the synthesis and secretion of numerous hormones belonging to the adipokine family, which also may regulate the course of pregnancy. Unfortunately, overweight and obesity lead to the expansion of adipose tissue in the body, and its excess in both women and animals contributes to changes in the synthesis and release of adipokines, which in turn translates into dramatic changes during pregnancy, including those taking place in the organ that is crucial for the proper progress of pregnancy, i.e. the placenta. In this chapter, we are summarizing the current knowledge about levels of adipokines and their role in the placenta, taking into account the physiological and pathological conditions of pregnancy, e.g. gestational diabetes mellitus, preeclampsia, or intrauterine growth restriction in humans, domestic animals, and rodents.

Impact of perinatal factors on biomarkers of cardiovascular disease risk in preadolescent children

BACKGROUND

This review aims to summarize associations of the perinatal environment with arterial biophysical properties in childhood, to elucidate possible perinatal origins of adult cardiovascular disease (CVD).

METHODS

A systematic search of PubMed database was performed (December 2020). Studies exploring associations of perinatal factors with arterial biophysical properties in children 12 years old or less were included. Properties studied included: pulse wave velocity; arterial stiffness or distensibility; augmentation index; intima-media thickness of aorta (aIMT) or carotids; endothelial function (laser flow Doppler, flow-mediated dilatation). Two reviewers independently performed study selection and data extraction.

RESULTS

Fifty-two of 1084 identified records were included. Eleven studies explored associations with prematurity, 14 explored maternal factors during pregnancy, and 27 explored effects of low birth weight, small-for-gestational age and foetal growth restriction (LBW/SGA/FGR). aIMT was consistently higher in offspring affected by LBW/SGA/FGR in all six studies examining this variable. The cause of inconclusive or conflicting associations found with other arterial biophysical properties and perinatal factors may be multifactorial: in particular, measurements and analyses of related properties differed in technique, equipment, anatomical location, and covariates used.

CONCLUSION

aIMT was consistently higher in LBW/SGA/FGR offspring, which may relate to increased long-term CVD risk. Larger and longer term cohort studies may help to elucidate clinical significance, particularly in relation to established CVD risk factors. Experimental studies may help to understand whether lifestyle or medical interventions can reverse perinatal changes aIMT. The field could be advanced by validation and standardization of techniques assessing arterial structure and function in children.

Early Life Determinants of Vascular Structure in Fetuses, Infants, Children, and Adolescents: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate the association between early life exposures during the first 1000 days (conception to age 24 months) and aortic intima-media thickness (aIMT), an early indicator of cardiovascular disease (CVD) risk, in youths.

STUDY DESIGN

The MEDLINE, Embase, Scopus, CINAHL, and Allied and Complementary Medicine databases were searched from inception to July 2021. Eligibility criteria included observational controlled studies in youths aged <20 years with risk factors/exposures during the first 1000 days and aIMT measurements (unadjusted mean ± SD). Outcome data were pooled using a random-effects meta-analysis. Meta-regression was used to investigate confounders.

RESULTS

A total of 8657 articles were identified, of which 34 were included in our meta-analysis. The age of participants ranged from 22.9 weeks gestation in utero to 10.9 years. In the meta-analysis (n = 1220 cases, n = 1997 controls), the following factors were associated with greater aIMT: small for gestational age (SGA) status (14 studies, mean difference, 0.082 mm; 95% CI, 0.051-0.112; P < .001; I² = 97%), intrauterine growth restriction (6 studies; mean difference, 0.198 mm, 95% CI, 0.088-0.309; P < .001; I² = 97%), preeclampsia (2 studies; mean difference, 0.038 mm; 95% CI, 0.024-0.051; P < .001; I² = 38%), and large for gestational age (LGA) status (3 studies; mean difference, 0.089 mm; 95% CI, 0.043-0.0136; P < .001; I² = 93%). In meta-regression, older age (P < .001), higher prevalence of maternal smoking (P = .04), and SGA (P < .001) were associated with greater difference in aIMT in preterm participants compared with controls. Limitations included the high heterogeneity present in most meta-analyses and the scope of our meta-regression.

CONCLUSIONS

Adverse early life exposures are associated with greater aIMT in youths, consistent with an increased risk for CVD later in life. Further research is needed to determine whether intervention and preventive strategies deliver clinical benefits to improve future cardiovascular health.

Influence of intrauterine growth status on aortic intima-media thickness and aortic diameter in near-term fetuses: a comparative cross-sectional study

Intrauterine undernutrition may lead to fetal vascular programming. We compared abdominal aortic intima-media thickness (aIMT) and aortic diameter (aD) between appropriate for gestational age (AGA) and growth-restricted fetuses (GRF). We recruited 136 singleton fetuses at 34-37 weeks of gestation from Fetal Medicine Unit of Aga Khan University Hospital, Karachi (January-November 2017). Subjects were classified as AGA (n = 102) and GRF (n = 34) using INTER-GROWTH 21st growth reference and standard ultrasound protocol. Their far- and near-wall aIMT and aD were compared after adjustment of maternal age, first-trimester body mass index, fetal gender, hypertension and hyperglycemia in pregnancy. As the severity of growth restriction increased in GRF, aIMT and aD showed an increasing and a decreasing trend, respectively. Both far- and near-wall aIMT in GRF [(adj. β = 0.082, 95% confidence interval [CI] 0.042-0.123) and (adj. β = 0.049, 95% CI 0.010-0.089)] were significantly greater with reference to AGA fetuses. GRF subgroup analysis into small for gestational age (SGA) fetuses and intrauterine growth restricted (IUGR) revealed highly significant difference between AGA and IUGR for far (0.142 mm, P-value < 0.001) and near-wall aIMT (0.115 mm, P-value < 0.001) and marginally significant aD difference (0.51 mm, P-value 0.05). These findings suggest that the extent of fetal aortic remodelling is influenced by the severity of growth restriction. Hence, the targeted interventions for the cardiovascular health promotion of IUGR and SGA born neonates are desirable during early childhood, particularly in set ups with high prevalence of low birth weight babies.

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

An increase in cholesterol levels is perceived during pregnancy and is considered as a normal adaptive response to the development of the fetus. In some pregnancies, excessive increase in total cholesterol with high levels of Low-Density Lipoprotein leads to maladaptation by the fetus to cholesterol demands, resulting in a pathological condition termed as maternal hypercholesterolemia (MH). MH is considered clinically irrelevant and therefore cholesterol levels are not routinely checked during pregnancy, as a consequence of which there is scarce information on its global prevalence in pregnant women. Studies have reported that MH during pregnancy can cause atherogenesis in adults emphasizing the concept of in utero programming of fetus. Moreover, Gestational Diabetes Mellitus, obesity and Polycystic Ovary Syndrome are potential risk factors which strengthen combined pathologies in placenta and fetuses of mothers with MH. However, lack of conclusive evidence on cholesterol transport and underlying programming demand substantial research to develop population-based life style strategies for women in their childbearing years. The current review focuses on the mechanisms and outcomes of MH from existing epidemiological as well as experimental data and presents a detailed insight on this novel risk factor of cardiovascular diseases.

The relationship between serum vitamin D levels and intima-media thickness in term infants

Increasing epidemiologic evidence indicates that vitamin D deficiency is linked to a series of diseases, including cardiovascular disease. This prospective study was designed to determine the relationship between 25 hydroxyvitamin D (25(OH)D) level and aortic intima-media thickness (aIMT) and carotid intima-media thickness (cIMT) in term healthy neonates. A total of 135 term, healthy infants were included in the study. Ultrasonographic measurements were performed at 24-48 h after birth. Blood samples were obtained from the umbilical cord at birth. The neonates were divided into four groups according to serum 25(OH)D vitamin levels. For the entire cohort, the mean 25 hydroxyvitamin D level was found to be 15.17 ± 9.66 ng/mL. The mean values of cIMT and aIMT measurements were 0.386 ± 0.052 and 0.412 ± 0.076 mm, respectively. In group 4, mean and maximum aIMT measurements were significantly lower than the other groups (p = <0.001 and 0.001, respectively). We did not observe any significant difference between groups regarding cIMT measurements. Correlation was found between aIMT and 25 hydroxyvitamin D levels (r = 0.295 p = < 0.001).Conclusion: We conclude that vitamin D deficiency may be associated with early relative intima-media thickening of the aorta already in the first week of life. What is Known: • Vitamin D deficiency is linked to a series of diseases, including cardiovascular disease. • Studies in adults and high-risk children have shown that the measurement of the intima-media thickness represents an excellent marker of subclinical atherosclerosis. What is New: • This is the first study evaluating the relationship between 25(OH)D vitamin level and intima-media thickness in term healthy neonates. • Vitamin D deficiency in neonates may induce atherosclerosis early in life and the aortic intima-media thickness measurements may be used as an early marker for detection.

Feasibility and reliability of carotid intima-media thickness measurements in nonsedated infants

INTRODUCTION

Carotid intima-media thickness (CIMT) is a surrogate marker for atherosclerosis. It is increased in adolescents and young adults at risk for future cardiovascular disease. However, it remains unclear if it can be considered as a surrogate marker for atherosclerosis in infancy as very few studies have been performed in infants.

OBJECTIVES

Our objective was to assess the feasibility and interobserver reproducibility of CIMT measurement in nonsedated infants.

METHODS

We measured CIMT in 81 infants less than 1 year of age. Repeated measurements were obtained by a second observer in 24 children. The analysis was performed with semiautomated edge detection software. Measurements with over 95% edge detection over a length of 1 cm were considered as valid. We further compared the measurements using the semiautomated method with measurements using the manual electronic caliper method in a subgroup of 10 infants.

RESULTS

Carotid ultrasound recordings and intima-media thickness measurements were obtained in 79% of infants (n = 64). Mean CIMT of the 64 infants measured by the first observer was 0.44 mm (SD: 0.04). In the 24 participants with measurements by two observers, the mean interobserver difference was 0.001 mm (SD: 0.026). The interobserver coefficient of variation was 5.9%. CIMT measurements obtained with the manual method (mean: 0.35; range: 0.29-0.39) were slightly lower than measurements obtained with the semiautomated method (mean: 0.38; range: 0.32-0.44). Measurements with both methods were highly correlated (r: 0.87).

CONCLUSION

Measurement of CIMT in nonsedated infants less than 1 year of age is feasible in the majority of infants with good interobserver variability.

Neonatal Arterial Morphology Is Related to Body Size in Abnormal Human Fetal Growth

BACKGROUND

Restriction in fetal growth is associated with cardiovascular disease in adulthood. It is unclear whether abnormal intrauterine growth influences arterial morphology during the fetal or neonatal stage. The objective was to study the regional arterial morphology with respect to gestational age and abnormal fetal body size.

METHODS AND RESULTS

We studied body anthropometrics and arterial morphology and physiology in 174 neonates born between 31 and 42 weeks of gestation, including neonates with birth weights appropriate, small, and large for age, with very high resolution vascular ultrasound (35-55 MHz). In simple linear regressions, parameters of body size (body weight, body surface area, and organ circumference) and gestational age were statistically significantly associated with common carotid, brachial, femoral arterial parameters (lumen diameter [LD], wall layer thickness [intima-media thickness and intima-media-adventitia thickness], and carotid artery wall stress [CAWS]). Male sex was statistically significantly associated with LD and CAWS. In multiple linear regression models, body size, gestational age, and sex explained a large proportion of the arterial variance (R( 2) range, 0.37-0.47 for LD; 0.09-0.35 for intima-media thickness; 0.21-0.41 for intima-media-adventitia thickness; and 0.23 for CAWS; all models P<0.001). Arterial wall layer thickness, LDs, and CAWS were independently and strongly predicted by body size, and no effect of maternal disease was observed when added to the models. Gestational age and male sex were also independently but more weakly associated with arterial LDs and CAWS (P<0.01), but not with arterial wall layers.

CONCLUSIONS

These results indicate that the intrauterine growth of fetal arterial LD and wall layer thickness are primarily attributed to body growth overall. LD and CAWS show weaker association with gestational age and sex.

Uteroplacental insufficiency reduces rat plasma leptin concentrations and alters placental leptin transporters: ameliorated with enhanced milk intake and nutrition

KEY POINTS

Uteroplacental insufficiency compromises maternal mammary development, milk production and pup organ development; this is ameliorated by cross-fostering, which improves pup growth and organ development and prevents adult diseases in growth-restricted (Restricted) offspring by enhancing postnatal nutrition. Leptin is transported to the fetus from the mother by the placenta; we report reduced plasma leptin concentrations in Restricted fetuses associated with sex-specific alterations in placental leptin transporter expression. Pup plasma leptin concentrations were also reduced during suckling, which may suggest reduced milk leptin transport or leptin reabsorption. Mothers suckled by Restricted pups had impaired mammary development and changes in milk fatty acid composition with no alterations in milk leptin; cross-fostering restored pup plasma leptin concentrations, which may be correlated to improved milk composition and intake. Increased plasma leptin and altered milk fatty acid composition in Restricted pups suckling mothers with normal lactation may improve postnatal growth and prevent adult diseases.

ABSTRACT

Uteroplacental insufficiency reduces birth weight and adversely affects fetal organ development, increasing adult disease risk. Cross-fostering improves postnatal nutrition and restores these deficits. Mothers with growth-restricted pups have compromised milk production and composition; however, the impact cross-fostering has on milk production and composition is unknown. Plasma leptin concentrations peak during the completion of organogenesis, which occurs postnatally in rats. Leptin is transferred to the fetus via the placenta and to the pup via the lactating mammary gland. This study investigated the effect of uteroplacental insufficiency on pup plasma leptin concentrations and placental leptin transporters. We additionally examined whether cross-fostering improves mammary development, milk composition and pup plasma leptin concentrations. Fetal growth restriction was induced by bilateral uterine vessel ligation surgery on gestation day 18 in Wistar Kyoto rats (termed uteroplacental insufficiency surgery mothers). Growth-restricted (Restricted) fetuses had reduced plasma leptin concentrations, persisting throughout lactation, and sex-specific alterations in placental leptin transporters. Mothers suckled by Restricted pups had impaired mammary development, altered milk fatty acid composition and increased plasma leptin concentrations, despite no changes in milk leptin. Milk intake was reduced in Restricted pups suckling uteroplacental insufficiency surgery mothers compared to Restricted pups suckling sham-operated mothers. Cross-fostering Restricted pups onto a sham-operated mother improved postnatal growth and restored plasma leptin concentrations compared to Restricted pups suckling uteroplacental insufficiency surgery mothers. Uteroplacental insufficiency alters leptin homeostasis. This is ameliorated with cross-fostering and enhanced milk fatty acid composition and consumption, which may protect the pups from developing adverse health conditions in adulthood.

Fetal Growth Restriction Induces Heterogeneous Effects on Vascular Biomechanical and Functional Properties in Guinea Pigs (Cavia porcellus)

Aim: Fetal growth restriction (FGR) is associated with a variety of cardiometabolic diseases in adulthood which could involve remodeling processes of the vascular walls that could start in the fetal period. However, there is no consensus whether this remodeling affects in a similar way the whole vascular system. We aimed to determine the effects of FGR on the vasoactive and biomechanical properties of umbilical and systemic vessels in fetal guinea pigs.

Methods: FGR was induced by implanting ameroid occluders at mid-gestation in uterine arteries of pregnant guinea pigs, whilst the control group was exposed to simulated surgery. At the term of gestation, systemic arteries (aorta, carotid and femoral) and umbilical vessels were isolated to determine ex vivo contractile and biomechanical responses (stretch-stress until rupture) on a wire myograph, as well as opening angle and residual stresses. Histological characteristics in tissue samples were measured by van Gieson staining.

Results: Aorta and femoral arteries from FGR showed an increased in biomechanical markers of stiffness (p < 0.01), contractile capacity (p < 0.05) and relative media thickness (p < 0.01), but a reduced internal diameter (p < 0.001), compared with controls. There were no differences in the biomechanical properties of carotid and umbilical from control and FGR fetuses, but FGR umbilical arteries had a decreased contractile response to KCl (p < 0.05) along with a reduced relative media thickness (p < 0.05).

Conclusion: Altogether, these changes in functional, mechanical and morphological properties suggest that FGR is associated with a heterogeneous pro-constrictive vascular remodeling affecting mainly the lower body fetal arteries. These effects would be set during a pathologic pregnancy in order to sustain the fetal blood redistribution in the FGR and may persist up to adulthood increasing the risk of a cardiovascular disease.

Impact of Decreased Serum Insulin-Like Growth Factor-1 Levels on Central Aortic Compliance in Small-for-Gestational-Age Infants

BACKGROUND

Intrauterine growth restriction is associated with arterial hypertension in adulthood; however, the underlying mechanism is unclear.

OBJECTIVES

We hypothesized that serum insulin-like growth factor-1 (IGF-1) levels affect central aortic elastic properties and structure in small-for-gestational-age (SGA) infants.

METHODS

Eighteen SGA infants and 22 appropriate-for-gestational-age (AGA) infants were enrolled in this study. The serum IGF-1 level within 1 h of birth and abdominal aortic echo parameters at 1 week of age were retrospectively compared.

RESULTS

In the SGA infants, IGF-1 levels (27.6 ± 17.7 vs. 42.6 ± 15 ng/ml, p = 0.006), aortic strain (10.2 ± 3.1 vs. 12.8 ± 3.1%, p = 0.01), and aortic distensibility (0.73 ± 0.19 vs. 0.92 ± 0.34 cm2/dyn × 10-4, p = 0.05) were significantly lower compared with AGA infants. By contrast, blood pressure, aortic intima-media thickness (aIMT) in relation to body weight (383 ± 163 vs. 256 ± 43 μm/kg, p < 0.001), aortic stiffness index in relation to body weight (2.0 ± 1.7 vs. 1.1 ± 0.4, p = 0.005), and arterial pressure-strain elastic modulus (293 ± 72 vs. 242 ± 78 mm Hg, p = 0.04) were higher compared with AGA infants. In the SGA infants, IGF-1 levels were significantly correlated with aortic strain (r = 0.49, p = 0.04), aIMT in relation to body weight (r = -0.61, p = 0.007), and aortic stiffness index in relation to body weight (r = -0.63, p = 0.005).

CONCLUSIONS

Decreased serum IGF-1 levels in SGA infants may affect the vascular compliance and structure of the central aorta.

Human fetal growth restriction: a cardiovascular journey through to adolescence

Intrauterine growth restriction has been noted to adversely impact morbidity and mortality in the neonatal period as well as cardiovascular well-being in adolescence and adulthood. Recent data based on a wide range of ultrasound parameters during fetal and neonatal life has noted early and persistent involvement of the cardiovascular system. Some of these measures are predictive of long-term morbidities. Assessment of vascular mechanics is a new and novel concept in this population, and opens up avenues for diagnosis, monitoring and evaluation of the likely effectiveness of interventions. Prevention of these adverse vascular and cardiac outcomes secondary to fetal growth restriction may be feasible and of clinical relevance. This review focuses on growth restriction in humans with respect to cardiovascular remodeling and dysfunction during fetal life, persistence of functional cardiac impairment during early childhood and adolescence, and possible preventive strategies.

Systemic arterial stiffness in infants with bronchopulmonary dysplasia: potential cause of systemic hypertension

OBJECTIVE

Systemic hypertension is common among preterm infants with severe bronchopulmonary dysplasia (BPD); the exact cause is unknown. The objective of this preliminary hypothesis generating study was to examine systemic arterial structure and vasomotor function in a cohort of preterm infants with severe BPD, using a cohort of preterm infants without BPD and a cohort of term infants for comparison.

STUDY DESIGN

After obtaining informed consent, we measured aortic wall thickness and vasomotor function by ultrasonography in 20 infants with severe BPD, 7 infants with no BPD, and compared them with 20 healthy term infants.

RESULTS

Maximum aortic thickness was significantly higher in infants with BPD (827±163 μm) compared to those with no BPD (674±22 μm) and term infants (657±67 μm) (unadjusted P<0.0001). The input impedance was similarly elevated in the infants with BPD (574±127 dynes s( )cm(-5)) compared to those with no BPD (325±24 dynes s cm(-)(5)) or term infants (328±113 dynes s cm(-)(5)) (unadjusted P<0.0001). Stiffness index was significantly higher in the infants with BPD (3.4±0.6) compared to those with no BPD (2.6±0.3) or term infants (2.3±0.4) (unadjusted P<0.0001). Systemic vascular resistance was also significantly elevated in the infants with BPD. The results remained significant even after adjusting for gestational age and birth weight. Measures of vasomotor function significantly correlated with blood pressure.

CONCLUSION

The aortic wall thickness and vasomotor function are significantly altered in preterm infants with severe BPD. These findings may explain the higher incidence of systemic hypertension in this population.

Intrauterine growth restriction: impact on cardiovascular development and function throughout infancy

Intrauterine growth restriction (IUGR) refers to the situation where a fetus does not grow according to its genetic growth potential. One of the main causes of IUGR is uteroplacental vascular insufficiency. Under these circumstances of chronic oxygen and nutrient deprivation, the growth-restricted fetus often displays typical circulatory changes, which in part represent adaptations to the suboptimal intrauterine environment. These fetal adaptations aim to preserve oxygen and nutrient supply to vital organs such as the brain, the heart, and the adrenals. These prenatal circulatory adaptations are thought to lead to an altered development of the cardiovascular system and "program" the fetus for life long cardiovascular morbidities. In this review, we discuss the alterations to cardiovascular structure, function, and control that have been observed in growth-restricted fetuses, neonates, and infants following uteroplacental vascular insufficiency. We also discuss the current knowledge on early life surveillance and interventions to prevent progression into chronic disease.

Immediate Postnatal Overfeeding in Rats Programs Aortic Wall Structure Alterations and Metalloproteinases Dysregulation in Adulthood

BACKGROUND

Alterations in the nutritional perinatal environment, such as intrauterine growth retardation with subsequent postnatal catch-up growth, program cardiovascular disease in adulthood, possibly through alterations in matrix metalloproteinase (MMP)-2 and -9. However, experimental evidences demonstrating that changes in the nutritional perinatal environment can program MMP-2 and -9 with subsequent alterations of vessel wall are lacking.

AIM

The current study evaluated whether immediate postnatal overfeeding is able to alter vascular morphological indexes and circulating and/or vascular MMP2-2 and -9 status.

METHODS

Aortic morphology (wall thickness and percentage of incomplete elastin lamellae) and circulating and aortic MMP-2 and -9 activity (measured by gelatin zymography) and aortic MMP-2 and -9 mRNA (measured by reverse transcription polymerase chain reaction (RT-PCR)) were studied in adult male rats overfed (OF) or normofed (NF) during the immediate postnatal period.

RESULTS

Postnatal overfeeding induced early onset obesity. Adult OF rats presented with increased blood pressure and circulating MMP-2 and -9 activity. In the thoracic aorta, postnatal overfeeding increased wall thickness and decreased elastin integrity (as demonstrated by an increased percentage of incomplete elastin lamellae). OF rats showed enhanced aortic MMP-2 activity and MMP-9 mRNA levels. Circulating and aortic MMP-2 activity correlated positively with the percentage of incomplete elastin lamellae and aortic wall thickness, respectively.

CONCLUSION

Our data demonstrate for the first time that immediate postnatal nutritional programming induces increases in circulating and aortic MMP-2 activity with parallel aortic wall alterations, such as decreased elastin integrity and enhanced thickening, showing that this experimental model is suitable for the study of perinatal nutritional programming of vascular functions.

Leptin in pregnancy and development: a contributor to adulthood disease?

Emerging research has highlighted the importance of leptin in fetal growth and development independent of its essential role in the maintenance of hunger and satiety through the modulation of neuropeptide Y and proopiomelanocortin neurons. Alterations in maternal-placental-fetal leptin exchange may modify the development of the fetus and contribute to the increased risk of developing disease in adulthood. In addition, leptin also plays an important role in reproductive functions, with plasma leptin concentrations rising in pregnant women, peaking during the third trimester. Elevated plasma leptin concentrations occur at the completion of organogenesis, and research in animal models has demonstrated that leptin is involved in the development and maturation of a number of organs, including the heart, brain, kidneys, and pancreas. Elevated maternal plasma leptin is associated with maternal obesity, and reduced fetal plasma leptin is correlated with intrauterine growth restriction. Alterations in plasma leptin during development may be associated with an increased risk of developing a number of adulthood diseases, including cardiovascular, metabolic, and renal diseases via altered fetal development and organogenesis. Importantly, research has shown that leptin antagonism after birth significantly reduces maturation of numerous organs. Conversely, restoration of the leptin deficiency after birth in growth-restricted animals restores the offspring's body weight and improves organogenesis. Therefore, leptin appears to play a major role in organogenesis, which may adversely affect the risk of developing a number of diseases in adulthood. Therefore, greater understanding of the role of leptin during development may assist in the prevention and treatment of a number of disease states that occur in adulthood.

Feasibility and precision of transcutaneous very-high resolution ultrasound for quantification of arterial structures in human neonates - comparison with conventional high resolution vascular ultrasound imaging

BACKGROUND

Non-invasive transcutaneous very-high resolution ultrasound (VHRU, 25-55 MHz) has recently been developed to quantify superficial vascular structures in humans. The performance of the method has yet not been evaluated in vivo in neonates. The aim of the study was to compare VHRU with conventional high-resolution ultrasound (HRU, 7-12 MHz), and to assess the feasibility and precision of VHRU in this population.

METHODS

150 images from central elastic (common carotid, CCA) and peripheral muscular (brachial, BA; femoral, FA) arteries were obtained in 25 neonates of different gestational ages (range 33 + 0 to 41 + 5 gestational weeks) and weights (range 1570-4950 g) with VHRU, and the use of HRU for comparison assessed in five.

RESULTS

Images were captured from CCAs with 35 MHz, FAs using 35 and 55 MHz, and BAs using 55 MHz. 12 MHz was unable to assess FAs and BAs, and the CCA IMT was grossly overestimated compared with 35-55 MHz. IMTs of the smallest BAs and FAs were beyond the axial resolution of VHRU (<0.05 mm), thus immeasurable. For VHRU, the intra-, inter- and test-retest coefficients of variation (CV) were for LDs (range 1.44-2.62 mm, CVs between 1.6 and 4.8%), IMATs (range 0.141-0.161 mm, CVs between 8.8 and 19.9%), and IMTs (range 0.062-0.165 mm, CVs between 12.8 and 24.8%) for the different arteries.

CONCLUSION

VHRU is feasible, accurate and precise in the assessment of superficial proximal conduit arteries but unable to assess the abdominal aorta in human neonates HRU-derived neonatal conduit arterial wall layer thicknesses are below the ultrasound axial resolution.

Brain-Sparing in Intrauterine Growth Restriction: Considerations for the Neonatologist

Intrauterine growth restriction (IUGR) is most commonly caused by placental insufficiency, in response to which the fetus adapts its circulation to preserve oxygen and nutrient supply to the brain ('brain-sparing'). Currently, little is known about the postnatal course and consequences of this antenatal adaptation of the cerebral circulation. The altered cerebral haemodynamics may persist after birth, which would imply a different approach with regard to cerebral monitoring and clinical management of IUGR preterm neonates than their appropriately grown peers. Few studies are available with regard to this topic, and the small body of evidence shows controversy. This review discusses the cerebral circulatory adaptations of IUGR fetuses and appraises the available literature on their postnatal cerebral circulation with potential clinical consequences.

Impact of intrauterine growth restriction on long-term health

PURPOSE OF REVIEW

Intrauterine growth restriction (IUGR) is responsible for the higher rates of fetal, perinatal, and neonatal morbidity and mortality. This review details the IUGR risk factors, its short and long-term sequel, the mechanism underlying the long-term consequences, and the strategies to tackle IUGR burden.

RECENT FINDINGS

Short-term consequences of IUGR involve metabolic, thermal, and hematological disturbances leading to morbidities. Long term consequences due to changes in the fetal nutritional environment is associated with increased risk of developing metabolic syndrome and cardiovascular disease, systolic hypertension, obesity, insulin resistance, and diabetes type II in adulthood. There are no effective therapies to reverse IUGR, and antenatal management is aimed at determining the ideal time and mode of delivery. In order to prevent complications associated with IUGR, it is important to first detect the condition and institute appropriate surveillance to assess fetal well-being coupled with suitable intervention in case of fetal distress.

SUMMARY

Reliable prediction of IUGR may be achieved by combining clinical risk factors with Doppler abnormalities, fetal growth, and biomarkers. If this can be achieved, there is potential to reduce future perinatal morbidity, mortality and long-term consequences, but steps geared toward the prevention of IUGR are of unparalleled importance.

Abdominal aortic intima-media thickness in preschool children born preterm

Recently aortic intima-media thickness (IMT) has been used as an earlier marker of preclinical atherosclerosis in high-risk children, such as those with type 1 diabetes mellitus and hypercholesterolemia. Children who were born preterm have an early elevation in insulin resistance, which may be a risk factor for metabolic syndrome in adulthood. However, there is no optimal marker of subsequent cardiovascular disease for children born preterm. In this study, we aimed to evaluate the effect of preterm birth on aortic IMT during the preschool period. Mean aortic IMT was measured by ultrasound in 26 subjects born preterm (gestational age <37 weeks [preterm group]) and 11 control subjects born at term (term group). The mean aortic IMT of the preterm group was significantly thicker than that of the term group (preterm group: median 577 μm, interquartile range (524-599) versus term group: 517 μm (442-544); p = 0.003). Mean aortic IMT may be one of the earlier markers of subclinical vasculopathy in preschool children who were born preterm.

Cardiac function and arterial biophysical properties in small for gestational age infants: postnatal manifestations of fetal programming

OBJECTIVE

To investigate the differences in cardiac function and arterial biophysical properties between term-born appropriate for gestational age (AGA) infants and small for gestational age (SGA) infants. Our hypothesis was that adaptation to intrauterine growth restriction induces changes in cardiac and arterial indices.

STUDY DESIGN

This was a prospective observational echocardiographic evaluation of cardiac and arterial indices in SGA infants and AGA infants. Demographic and echocardiographic data were compared between 20 inborn term SGA infants with birth weight <3rd percentile for gestational age and 20 AGA infants.

RESULTS

The Ponderal index was significantly lower and blood pressure was significantly higher in the SGA infants compared with the AGA infants. Left ventricular output was lower in the SGA infants (170 ± 31 mL/kg/min vs 197 ± 39 mL/kg/min). Diastolic dysfunction was greater in the SGA infants (ie, reduced E and A wave velocities, higher E/A ratio [1.08 ± 0.16 vs 0.85 ± 0.07], and prolonged isovolumic relaxation time [73 ± 6.2 ms vs 62.6 ± 3.6 ms]). Aortic intima-media thickness was significantly greater in the SGA infants (822 ± 105 μm vs 694 ± 52 μm), as were arterial wall stiffness index and input impedance.

CONCLUSION

Cardiac function and arterial biophysical properties were altered in the SGA infants. The findings complement the information on the association between in utero growth and cardiovascular morbidity in later life.

Genotype-specific alterations in vascular smooth muscle cell function in cystic fibrosis piglets

BACKGROUND

The most common CF-causing mutations interfere with CFTR trafficking from the endoplasmic reticulum (CFTR-F508del) or prematurely terminate transcription (CFTR-null). We suspected that genotype-specific patterns of CFTR expression would have differential effects on smooth muscle cell calcium signaling and hence vascular tone. We hypothesized that compared to wild-type or CFTR-null aorta, aorta from CFTR-F508del (dF) piglets will have reduced endoplasmic reticulum calcium mobilization and decreased vasoconstriction.

METHODS

Aortic reactivity was assessed by myography, and ratiometric calcium imaging was performed in isolated vascular smooth muscle cells.

RESULTS

Aorta from dF piglets had reduced myogenic tone (P<0.001) and decreased constriction to KCl (P<0.05). Combined inhibition of ryanodine and IP3 receptors decreased wild-type and CFTR-null responses to levels seen in dF aorta. Compared to wild-type cells, dF-expressing smooth muscle cells had reduced calcium transients, while CFTR-null cells had decreased baseline intracellular calcium concentrations.

CONCLUSIONS

Expression of CFTR-F508del interferes with smooth muscle cell calcium handling and decreases aortic responsiveness.

Relative intima-media thickening after preterm birth

AIM

Preterm infants are at increased risk of early arterial growth arrest and cardiovascular mortality. We assessed intima-media thickness (IMT) - an early marker of accelerated vascular ageing - in very preterm infants.

METHODS

Longitudinal cohort study of 21 very preterm and 29 term infants, all with appropriate birthweights. Intima-media thickness was assessed by M-Mode ultrasound of the aorta and carotid arteries at three occasions during a 6-month period corresponding to the third trimester of pregnancy and ending 3 months after term equivalent age.

RESULTS

No differences in absolute aortic or carotid IMT were found. However, in relation to vessel lumen diameter, the IMT switched from being narrower in preterm infants, compared with foetuses at 28 weeks of gestation, to being significantly thicker in both the aorta and carotid artery in older infants born preterm, compared with term controls of equivalent postmenstrual age. Although the aortic and carotid artery diameters increased significantly with postnatal age, IMT did not.

CONCLUSION

In relation to vessel diameter, subjects born preterm show thicker intima-media in the great arteries than infants born at term. It remains to be established whether this relative intima-media thickening persists and may be a risk marker for future cardiovascular disease.

Cardiovascular function in adulthood following intrauterine growth restriction with abnormal fetal blood flow

OBJECTIVES

To examine whether intrauterine growth restriction (IUGR) is associated with increased cardiovascular risk later in life.

METHODS

We examined 19 young adults (aged 22-25 years) who were born at term after IUGR, along with 18 controls. All had been examined previously with fetal Doppler, and in the present follow-up with echocardiography, carotid echo-tracking ultrasound, applanation tonometry, blood pressure and laser Doppler, in order to characterize their cardiac and vascular geometry and/or function.

RESULTS

The diameter of the ascending aorta and the left ventricular diameter were smaller in the IUGR group, but only ascending aortic diameter remained significantly smaller after adjustment for body surface area (P < 0.05). The aortic pressure augmentation index was higher in the IUGR group (P < 0.05). The common carotid artery diameter, intima-media thickness and distensibility as well as left ventricular mass and function were similar in the two groups. IUGR status was found to be an independent predictor of ascending aortic diameter.

CONCLUSIONS

IUGR due to placental dysfunction seems to contribute to the higher systolic blood pressure augmentation and the smaller aortic dimensions that are observed in adults more than 20 years later, with possible negative consequences for future left ventricular performance due to increased aortic impedance.

Developmental origins of adult diseases

There is considerable evidence for the fact that early life environment in human beings are associated with future development of various metabolic diseases. Fetal programming and perinatal events appear to exert effects on later life that are independent of environmental risk factors in adults. Our understanding of the underlying mechanisms are limited and remains unclear. However several animal models and epidemiological studies have shown this association, and it is assumed secondary to the penalties of developmental plasticity. In this review, we amalgamate facts from several disciplines to support this hypothesis.

Aortic intima-media thickness in nicotine-exposed rat pups during gestation and lactation period

There have been several studies confirming an association between maternal smoking during pregnancy and low birth weight. The detrimental effect of nicotine exposure beginning in fetal life continues during lactation, in infancy and in the early childhood period. In our previous studies, we found increased aortic intima-media thickness (aIMT) as a preatherosclerotic lesion in neonates with intrauterine growth restriction and in infants of smoking mothers. We aimed to evaluate histopathologically the effect of nicotine exposure during pregnancy and lactation period on fetal growth and aIMT at postnatal 45 days of age (end of the mid-adolescent period) in rat pups living in the same conditions. Gravid rats were assigned into three groups. In nicotine A, pregnant rats received 6 mg/kg/day nicotine intraperitoneally during pregnancy from 1 to 21 days of gestation and lactation (until postnatal day 21). Nicotine B received 3 mg/kg/day nicotine for the same period. Control pregnant rats received only saline intraperitoneally. Abdominal aIMT was studied histopathologically at postnatal 45 days of age. Nicotine exposure resulted in decreased birth weight and pregnancy weight gain. The mean aIMT values of the rat pups exposed to nicotine in both nicotine A and B groups were higher than those of the control group (103.78 ± 21.33 μm, 99.11 ± 30.12 μm, and 62.56 ± 7.18 μm, respectively). In conclusion, the detrimental effect on birth weight of nicotine exposure that began in fetal life is dose dependent. Nicotine exposure during intrauterine life and the lactation period causes increased aIMT in rat pups.

The relationship between abdominal aortic intima-media thickness and lipid profile in neonates born to mothers with preeclampsia

Neonates born to mothers with preeclampsia are known to be associated with lipid alterations that might increase the risk for cardiovascular disease in adult life. The aim of this study was to investigate the effect of preeclampsia on lipid metabolism, aortic intimamedia thickness (aIMT) and subsequent atherogenic risk in newborn infants. Aortic intima-media thickness was measured in 60 neonates of mothers with preeclampsia (group I; 30 neonates of mothers with preeclampsia and group II; 30 neonates of mothers with severe preeclampsia) and 30 healthy neonates (group III). Maternal and cord serum lipid profiles were determined in all groups. Mean abdominal aIMT measurements were higher in the neonates born to mothers with preeclampsia (group I; 0.36 +/- 0.03 mm and group II; 0.36 +/- 0.04 mm) compared with the control group (group III; 0.33 +/- 0.03 mm, p = 0.006). Serum triglyceride levels were significantly higher in the neonates born to mothers with preeclampsia (group I; 39.2 +/- 42.0 mg/dl and group II; 39.5 +/- 56.5 mg/dl) compared with the control group (group III; 14.9 +/- 18.8 mg/dl, p = 0,039). Serum HDL cholesterol levels were significantly lower in the neonates born to mothers with preeclampsia (group I; 17.3 +/- 12.3 mg/dl and group II; 17.1 +/- 12.8 mg/dl) compared with the control group (group III; 27.6 +/- 13.0 mg/dl, p = 0.002). In conclusion; neonates of mothers with preeclampsia have significantly higher aIMT with lipid alterations. This may play a role in the pathogenesis of atherosclerosis in adult life.

Relationship between Aortic Intima-media Thickening, Serum IGF-I and Low-density Lipoprotein Particle Diameter in Newborns with Intrauterine Growth Restriction

Much epidemiological evidence has linked low birth weight with late cardiovascular risk. In order to investigate the effect of intrauterine growth restriction (IUGR) on early atherosclerosis in the fetus, we measured aortic wall thickness (abdominal aortic intima-media thickness: aIMT) by ultrasonography in 15 neonates with IUGR and in 31 neonates considered to be appropriate for gestational age (AGA). Furthermore, we evaluated the relationship between aIMT, serum insulin-like growth factor-I (IGF-I) and low-density lipoprotein (LDL) particle size to investigate the possible effect of these atherosclerosis-related factors on the early atherosclerosis process. The results showed that the mean aIMT was significantly greater in the IUGR neonates than in the AGA neonates (least squares mean ± SE, 537 ± 24.8 vs. 471 ± 17.0 µm, p=0.037). The serum IGF-I levels were lower in the IUGR neonates than in the AGA neonates (27.9 ± 4.3 vs. 42.7 ± 2.9 ng/ml, p=0.009). A significant negative correlation was observed between aIMT and IGF-I in the IUGR neonates (r=–0.646, p=0.009); however, a positive correlation was observed between aIMT and IGF-I (r=0.416, p=0.020) in the AGA neonates. There appeared to be no relationship between aIMT and LDL particle diameter. Atherogenic small, dense LDL was not detected in the IUGR infants. In conclusion, neonates with IUGR have significant aortic thickening with decreased IGF-I, suggesting that prenatal events might predispose them to later cardiovascular risk.

Intrauterine growth restriction and adult disease: the role of adipocytokines

Intrauterine growth restriction (IUGR) is the failure of the fetus to achieve his/her intrinsic growth potential, due to anatomical and/or functional disorders and diseases in the feto-placental-maternal unit. IUGR results in significant perinatal and long-term complications, including the development of insulin resistance/metabolic syndrome in adulthood. The thrifty phenotype hypothesis holds that intrauterine malnutrition leads to an adaptive response that alters the fetal metabolic and hormonal milieu designed for intrauterine survival. This fetal programming predisposes to an increased susceptibility for chronic diseases. Although the mechanisms controlling intrauterine growth are poorly understood, adipose tissue may play an important role in linking poor fetal growth to the subsequent development of adult diseases. Adipose tissue secretes a number of hormones, called adipocytokines, important in modulating metabolism and recently involved in intrauterine growth. This review aims to summarize reported findings concerning the role of adipocytokines (leptin, adiponectin, ghrelin, tumor necrosis factor (TNF), interleukin-6 (IL6), visfatin, resistin, apelin) in early life, while attempting to speculate mechanisms through which differential regulation of adipocytokines in IUGR may influence the risk for development of chronic diseases in later life.