Intrauterine Growth Restriction (IUGR) Induces Signs of Subclinical Atherosclerosis in 6-Year-Old Infants Despite Absence Of Excessive Growth.

Background Postnatal catch-up growth and rapid weight gain after intrauterine growth restriction (IUGR) seem to increase the risk for later disease. This study aimed to compare features of the metabolic syndrome early in life between IUGR and appropriate for gestational age (AGA) infants. Patients Data for 9 infants with IUGR defined by a birth weight<10th percentile and ultrasound-proven placental insufficiency and 11 AGA children were available. Method Postnatal growth, auxological, cardiovascular, and metabolic parameters up to a chronological age of 6 years were assessed: Fasting serum concentrations of LDL-cholesterol, insulin, leptin, IGF-I, DHEAS, skinfold thicknesses, blood pressure, and mean carotid intima-media thickness (cIMT). Results All IUGR infants showed catch-up growth, although mean BMI SDS and total subcutaneous fat mass at the age of 6 years were still slightly lower compared to the AGA cohort. Reduced serum leptin concentrations were observed in IUGR infants (p=0.02), whereas no significant difference was found for IGF-I, insulin, LDL-cholesterol and DHEAS concentrations. Mean cIMT was significantly higher in IUGR infants (p<0.05). Mean arterial pressure did no differ. Discussion and Conclusion In 6-year-old IUGR infants with catch-up growth, who still had a slightly reduced BMI SDS compared to the AGA group, signs of subclinical atherosclerosis were detectable suggesting that cardiovascular risk in IUGR may be present even in the absence of excessive growth.

Differential effects of low birthweight and intrauterine growth restriction on umbilical cord blood insulin-like growth factor concentrations.

OBJECTIVE: Alterations in the growth hormone-insulin-like growth factor (IGF) axis have been considered as a causal factor for intrauterine growth restriction (IUGR) and for the increased risk of metabolic disease in later life. We compared members of the IGF axis in umbilical cord blood between IUGR neonates, small for gestational age without foetal restriction (SGA) and appropriate for gestational age (AGA) neonates. DESIGN: Prospective controlled multicenter study. PATIENTS: Sixteen ultrasound-proven IUGR, 8 SGA and 40 AGA neonates. MEASUREMENTS: Concentrations of total IGF-I and total IGF-II by immunoassays, bioactive IGF by cell-based bioassay and IGFBP-I in mixed venous and arterial umbilical cord blood samples at birth. Auxological parameters at birth. RESULTS: IGF-I concentrations in IUGR [17·7 µg/l (CI 13·8;21·6)] were clearly below those in AGA [48·3 µg/l (CI 43·7;52·9)] and SGA neonates [36·0 µg/l (CI 26·6;45·4)]. IGF-II levels were significantly reduced in IUGR [201·4 µg/l (CI 190·2;212·6)] compared to AGA neonates [231·2 µg/l (CI 220·6;241·9)]. A trend for lower IGF-II concentrations was observed in IUGR when compared to SGA neonates [232·0 µg/l (CI 207·2;256·8)]. These differences could not be explained by confounding. For IGFBP-1, a trend towards higher values in IUGR was observed. CONCLUSIONS: Low IGF-I cord blood concentrations in hypotrophic neonates after IUGR might not only result from low birthweight per se, but also reflect prenatal placental environment. Alterations of the IGF axis could be in the causal pathway of IUGR and thus constitute a potential surrogate marker for IUGR in the assessment of foetal programming.

DNA methylation of the p66Shc promoter is decreased in placental tissue from women delivering intrauterine growth restricted neonates.

OBJECTIVE: The adaptor protein p66Shc generates mitochondrial reactive oxygen species and translates oxidative signals into apoptosis. We aimed to analyze potential alterations in total methylation and in p66Shc activation in placental tissues from women delivering intrauterine growth restricted neonates (IUGR) versus appropriate for gestational age (AGA) and small for gestational age (SGA) neonates. METHOD: DNA methylation of the p66Shc promoter and of long interspersed nuclear elements (LINE-1), as a marker for total methylation, was quantified by automatic pyrosequencing in 15 IUGR, 25 AGA and 15 SGA placentas. Placental gene expression of p66Shc was determined by TaqMan real-time polymerase chain reaction. RESULTS: No significant difference was found for LINE-1 methylation between IUGR, AGA and SGA newborns. DNA methylation of the p66Shc promoter was significantly decreased in the IUGR compared with the AGA group (p < 0.0001) and the SGA group (p < 0.0001). However, analysis of placental p66Shc gene expression did not show a significant difference between the three groups. CONCLUSION: It remains speculative if the decreased p66Shc promoter methylation might play a role in the pathophysiology of endothelial dysfunction and cardiovascular disease after IUGR.

Intrauterine growth restriction (IUGR) is associated with increased leptin synthesis and binding capability in neonates.

OBJECTIVE: Animal studies suggest pathological foetal programming of hypothalamic circuits regulating food intake in the setting of leptin deficiency and intrauterine growth restriction (IUGR). We aimed to compare placental leptin synthesis and leptin-binding capability in venous cord blood between IUGR newborns and neonates born appropriate for gestational age (AGA). DESIGN: Prospective controlled multicentre study. PATIENTS: Twenty-one ultrasound-proven IUGR and 33 AGA neonates. MEASUREMENTS: The concentration of leptin and soluble leptin receptor (sOB-R) in venous cord blood at birth was determined. Moreover, placental gene and protein expression of leptin and placental mRNA expression of functional and total leptin receptor isoforms were measured. RESULTS: Whereas log-leptin concentration in venous cord blood did not differ between IUGR and AGA newborns, the concentration of log-sOB-R was elevated in IUGR neonates (p(confounder adjusted)=0·009). Placental leptin protein synthesis as well as leptin mRNA was significantly higher in IUGR than in AGA infants (log-transformed, relative gene expression, p(confounder adjusted)=0·004). Analysis of gene expression of functional and total leptin receptor isoforms did not show any difference between both groups. CONCLUSIONS: Leptin-binding capability in venous cord blood is increased in IUGR newborns. Thus, via foetal programming, reduced biologically active leptin levels might contribute to a perturbed regulation of appetite.

Placental 11beta-HSD2 gene expression at birth is inversely correlated with growth velocity in the first year of life after intrauterine growth restriction.

Intrauterine growth restriction (IUGR) is associated with an increased risk for short stature and diseases in adulthood thought to be inflicted by fetal programming. We hypothesized that placental endocrine systems involved in perinatal growth might also play a role in postnatal growth after IUGR. In a prospective controlled multicenter study, placental gene expression of IGF-binding protein-1 (IGFBP-1), leptin and 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) were measured in 14 IUGR infants and 15 children born appropriate for gestational age (AGA) proven by serial ultrasound examinations. Postnatally, IUGR infants experienced a significantly higher growth velocity than AGA neonates (at 1 y: p = 0.001). Gene expression of 11beta-HSD2 at birth correlated positively with birth length (r = 0.55, p = 0.04) and inversely with growth velocity in the first year of life (r = -0.69, p = 0.01) in the IUGR, but not in the AGA group. There was no correlation between gene expression of placental IGFBP-1, leptin and birth weight, length and growth velocity during the first year of life. AGA infants showed significantly higher concentrations of cortisone in venous cord blood after birth (p = 0.02) as a surrogate of a higher 11beta-HSD2 activity in the fetoplacental unit. In conclusion, placental 11beta-HSD2 gene expression might predict postnatal growth in IUGR.

Simultaneously reduced gene expression of cortisol-activating and cortisol-inactivating enzymes in placentas of small-for-gestational-age neonates.

OBJECTIVE: The enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) converts cortisol into cortisone. Reduced placental activity of 11beta-HSD2 in small-for-gestational-age (SGA) neonates results in fetal cortisol excess. In the present study, we examined the yet unknown gene expression of 11beta-HSD1, which primarily synthesizes cortisol in SGA placenta. STUDY DESIGN: In placentas taken from 24 women with normal-weight newborns and 16 women with SGA neonates, expression of 11beta-HSD1 and 11beta-HSD2 messenger ribonucleic acid (mRNA) was determined using reverse transcription-polymerase chain reaction. RESULTS: Placental mRNA expression of 11beta-HSD1 and 11beta-HSD2 was significantly reduced in the SGA group (P = .006 and P < .0001). Both enzymes showed a significant correlation to birthweight SD score and placental weight. Also, levels of both enzymes were significantly correlated. CONCLUSION: In placental tissue of SGA neonates 11beta-HSD2 and 11beta-HSD1 gene expression is reduced. Adapted levels of 11beta-HSD1 might result in a counterregulatory mechanism limiting transplacental passage of elevated cortisol levels.

Dexamethasone stimulates the expression of leptin and 11ß-HSD2 in primary human placental trophoblastic cells.

OBJECTIVES: Fetal glucocorticoid excess is thought to play an important role in early-life programming, promoting growth restriction and contributing to adult metabolic, cardiovascular and neuroendocrine disease. We hypothesized that dexamethasone incubation of primary trophoblastic cells from human healthy placentas at term might induce altered gene and protein expression of several endocrine placental regulators. STUDY DESIGN: Primary villous trophoblastic cells were incubated with 10 µM dexamethasone for 6, 12, 24, 48 and 72 h. Non-incubated trophoblastic cells served as vehicle control. Gene expression of leptin, 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) and insulin-like growth factor-binding protein-1 (IGFBP-1) was measured. Moreover, leptin, ß-human chorionic gonadotropine (ß-hCG) and lactate dehydrogenase (LDH) release into the culture medium was determined. RESULTS: Leptin gene expression was significantly increased in dexamethasone-incubated trophoblastic cells after 24, 48 and 72 h. There was a significant increase in leptin concentration in the medium of the cell culture after 48 h. Gene expression of 11ß-HSD2 was significantly higher in dexamethasone-stimulated trophoblastic cells compared to vehicle controls after 72 h. The expression rate of IGFBP-1 mRNA was basal throughout the incubation period. The concentration of ß-HCG in the supernatant increased significantly after 72 h of dexamethasone incubation, while LDH concentrations remained stable. CONCLUSION: Our findings suggest that dexamethasone incubation stimulates leptin and 11ß-HSD2 gene expression in primary villous trophoblastic cells of healthy human placentas, while enhancing cytotrophoblast differentiation.

Gene expression of placental hormones regulating energy balance in small for gestational age neonates.

OBJECTIVE: Fetal growth restriction is associated with an increased risk for metabolic and cardiovascular disease in later life. To further elucidate mechanisms that might be involved in the process of prenatal programming, we measured the adipokines leptin, resistin, and adiponectin and the GH-releasing hormone ghrelin in the placenta of small for gestational age (SGA) neonates. STUDY DESIGN: The control group included 24 placentas of appropriate for gestational age (AGA) newborns, in the study group were 16 placentas of SGA neonates. Gene expression of leptin, resistin, adiponectin, and ghrelin was examined. For hormones showing alterations in gene regulation placental protein expression was measured by Western blot. RESULTS: Placental mRNA expression of leptin was significantly increased in SGA placentas (p=0.0035, related to beta-actin). Protein concentration was increased, as well. There were no differences in placental resistin, adiponectin, or ghrelin gene expressions between SGA neonates and controls. Leptin was the only hormone to demonstrate a significant inverse correlation with birth weight (r=-0.44, p=0.01). Adiponectin correlated significantly with leptin (r=0.53, p=0.0023) and ghrelin (r=0.50, p=0.0045). CONCLUSIONS: Placental leptin gene expression and protein concentration showed the expected increase in the SGA group. Leptin was inversely correlated with birth weight. Positive correlation of adiponectin with leptin and ghrelin expression suggests an interaction between these hormones in the placenta. However, the unchanged expression of resistin, adiponectin, and ghrelin in SGA placentas and the absence of correlation with birth weight cast doubt whether these hormones produced in the placenta play a key role in fetal programming.