The contributions of plasma IGF-I, IGFBP-3 and leptin to growth in extremely premature infants during the first two years

Insulin-like growth factor-1 and insulin-like growth factor binding protein-3 as early predictors of growth, body composition, and neurodevelopment in preterm infants

OBJECTIVE

To investigate the relationship between insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3) and long-term growth, body composition, and neurodevelopment in preterm infants.

STUDY DESIGN

Prospective data were collected from ≤32 weeks gestational age infant cohort (N = 50). IGF-1 and IGFBP-3 concentrations were measured at 1 week (early) and 35 weeks (late) post-menstrual age (PMA). Growth, body composition, and neurodevelopment outcomes were measured at 4 and 12 months PMA. Relationships were measured by linear regression analysis.

RESULTS

Early IGFBP-3 concentration was positively associated with neurodevelopment at 12 months PMA. Early IGF-1 concentration was positively associated with weight at 4 months PMA, head circumference at 12 months PMA, and body mass index at 12 months PMA. Late IGFBP-3 concentration was positively associated with weight at 4 months PMA.

CONCLUSION

Further investigation of these associations may lead to novel biomarkers and/or treatments to optimize health outcomes in preterm infants.

An exploratory study of clinical factors associated with IGF-1 and IGFBP-3 in preterm infants

BACKGROUND

Despite advances in parenteral nutrition, postnatal growth failure in very low birthweight (VLBW) preterm infants is common and associated with chronic health problems. Insulin-like growth factor 1 (IGF-1) is positively associated with improved infant growth, but factors which promote IGF-1 levels in this population have not been clearly identified. The objective of this study was to explore early factors that influence IGF-1 in VLBW preterm infants.

METHODS

VLBW infants were enrolled into a prospective, randomized controlled nutrition trial (N = 87). Outcome measures included IGF-1 and IGFBP-3 levels measured at 35 weeks PMA. Linear regression analyses tested the relationships between candidate clinical predictors and levels of IGF-1 and IGFBP-3.

RESULTS

Higher protein intake, longer duration of parenteral nutrition, and lower IGFBP-3 levels at 1 week of life were associated with lower IGF-1 levels at 35 weeks PMA. Neither early markers of insulin resistance nor degree of illness were associated with IGF-1 levels at 35 weeks PMA.

CONCLUSION

Optimization of early nutrient intake, and attention to route of delivery, may have a lasting influence on IGF-1/IGFBP-3, and in turn, long-term health outcomes.

IMPACT

In very low birthweight preterm infants, early protein intake, duration of parenteral nutrition, and insulin-like growth factor binding protein 3 (IGFBP-3) levels at 1 week of life are positively associated with insulin-like growth factor 1 (IGF-1) levels at 35 weeks postmenstrual age. Data from this study highlight the influence of early nutrition on components of the endocrine axis in preterm infants. Strategies aimed at early initiation of enteral nutrition, as well as optimizing composition of parenteral nutrition, may bolster hormones involved in promoting preterm infant growth.

Short- and Long-Term Outcomes of Preeclampsia in Offspring: Review of the Literature

Preeclampsia is a multisystemic clinical syndrome characterized by the appearance of new-onset hypertension and proteinuria or hypertension and end organ dysfunction even without proteinuria after 20 weeks of pregnancy or postpartum. Residing at the severe end of the spectrum of the hypertensive disorders of pregnancy, preeclampsia occurs in 3 to 8% of pregnancies worldwide and is a major cause of maternal and perinatal morbidity and mortality, accounting for 8-10% of all preterm births. The mechanism whereby preeclampsia increases the risk of the neurodevelopmental, cardiovascular, and metabolic morbidity of the mother's offspring is not well known, but it is possible that the preeclamptic environment induces epigenetic changes that adversely affect developmental plasticity. These developmental changes are crucial for optimal fetal growth and survival but may lead to an increased risk of chronic morbidity in childhood and even later in life. The aim of this review is to summarize both the short- and long-term effects of preeclampsia on offspring based on the current literature.

Prenatal exposure to preeclampsia as a risk factor for long-term endocrine morbidity of the offspring

Objective: To analyze preeclampsia as a risk factor for pediatric endocrine disease. Study Design: A population-based cohort analysis comparing the risk of endocrine morbidity of children born between 1991-2014 to mothers with and without preeclampsia. Results: The study included 253,808 deliveries. Exposed offspring had significantly more endocrine hospitalizations (0.7% vs 0.4%; p < 0.001), specifically obesity (0.4% vs 0.2%, p < 0.001). While controlling for confounders, the exposed offspring had significantly more endocrine morbidity (OR 1.433 95% CI 1.115-1.841 p = 0.005). Conclusion: Preeclampsia is an independent risk factor for long-term endocrine disease of the offspring, specifically obesity.

Adipokines played a limited role in predicting temporary growth differences between very low birthweight infants with and without bronchopulmonary dysplasia

AIMS

This study explored whether growth was poorer among very low birthweight (VLBW) infants with bronchopulmonary dysplasia (BPD) and assessed adipokine levels as predictors of early growth.

METHODS

We studied 53 VLBW infants born in Tampere University Hospital up to 12 months of corrected age (CA). The median gestational age of the 21 infants with BPD and 32 infants without BPD was 29 weeks, and the median birthweights were 930 (635-1470) and 1185 (650-1470) grams. Growth parameters, macronutrients intake and plasma levels of adipokines were measured.

RESULTS

Bronchopulmonary dysplasia infants were lighter than controls until 36 weeks of CA, with catch-up growth achieved by three months of CA. Adipsin levels were lower in BPD infants at 28 days of postnatal age. High leptin levels seemed protective for low weight for height at nine months of CA. The duration of ventilator therapy predicted low weight for height, length for age and body mass index and BPD predicted low length for age at 12 months of CA.

CONCLUSIONS

Catch-up growth in VLBW infants with BPD was achieved by three months of CA, but adipokines played a limited role in predicting growth. Shortening ventilator therapy could help growth in VLBW infants.

IGF-I and relation to growth in infancy and early childhood in very-low-birth-weight infants and term born infants

Background

In very-low-birth-weight infants IGF-I plays an important role in postnatal growth restriction and is probably also involved in growth restriction in childhood. We compared IGF-I and its relation to growth in early childhood in very-low-birth-weight infants and term appropriate for gestational age born infants.

Methods

We included 41 very-low-birth-weight and 64 term infants. Anthropometry was performed at all visits to the outpatient clinic. IGF-I and insulin were measured in blood samples taken at 6 months and 2 years corrected age (very-low-birth-weight children) and at 3 months, 1 and 2 years (term children).

Results

Over the first 2 years of life growth parameters are lower in very-low-birth-weight children compared to term children, but the difference in length decreases significantly. During the first 2 years of life IGF-I is higher in very-low-birth-weight children compared to term children. In both groups there is a significant relationship between IGF-I and (change in) length and weight over the first 2 years of life and between insulin and change in total body fat.

Conclusions

Considering the relation of IGF-I to growth and the decrease in difference in length, higher IGF-I levels in very-low-birth-weight infants in early childhood probably have an important role in catch-up growth in length.

Relationship between fat mass measured by dual-energy X-ray absorptiometry and leptin in preterm infants between term age and 6 months' corrected age

BACKGROUND/AIMS

In term subjects, fat mass (FM) is positively associated with leptin, whereas studies in preterm infants show conflicting results. However, none of these studies measured FM by dual-energy X-ray absorptiometry (DEXA). This study aims to relate FM measured by DEXA in relation to leptin and growth in preterm infants.

METHODS

In 139 preterm infants, weight (kg) and length (cm) were measured at birth, term age, and 6 months' corrected age (CA). FM (kg), measured by whole-body DEXA, and leptin (µg/l) were measured at term age and 6 months' CA.

RESULTS

At term age and 6 months' CA, FM was associated with leptin (β = 1.94, 95% CI: 1.51-2.36, and β = 0.37, 95% CI: 0.26-0.48, respectively; p < 0.001). Gain in weight standard deviation score (SDS) between term age and 6 months' CA was associated with FM and leptin at 6 months' CA (β = 0.24, 95% CI: 0.18-0.30, and β = 0.25, 95% CI: 0.16-0.33, respectively; p < 0.001).

CONCLUSION

In preterm infants, FM measured by DEXA is associated with leptin, which indicates that leptin is a marker of body FM during the first 6 months after term age. Gain in weight SDS between term age and 6 months' CA results in higher FM and higher leptin at 6 months' CA.

Growth in preterm infants until six months postterm: the role of insulin and IGF-I

BACKGROUND/AIMS

Since insulin-like growth factor type I (IGF-I) and insulin regulate growth in term infants, they were studied in relation to nutrient intake and growth until 6 months corrected age (CA) in preterm infants.

METHODS

In 138 preterm infants (51% male, gestational age (expressed as median (IQR)) 30.6 (1.9) weeks, birth weight 1,368 (389) g) weight SDS, length SDS, IGF-I, and insulin were measured at term age, 3 and 6 months CA.

RESULTS

IGF-I and insulin at term age were associated with weight SDS and length SDS at term age and 3 months CA. IGF-I and insulin at 3 months CA were associated with weight SDS and length SDS at 3 and 6 months CA. IGF-I and insulin at term age were negatively associated with gain in weight SDS and gain in length SDS between term age and 6 months CA (IGF-I: β = -1.03, 95% CI -1.65;-0.41, p = 0.001 and β = -0.78, 95% CI -1.32;-0.23, p = 0.005; insulin: β = -0.19, 95% CI -0.37;-0.01, p = 0.044 and β = -0.18, 95% CI -0.35;-0.01, p = 0.035). Nutrient intake was not associated with IGF-I or insulin.

CONCLUSIONS

The present study suggests that IGF-I and insulin are important growth regulators in preterm infants until 6 months CA, independent of nutrient intake.

Adiposity in adolescent offspring born prematurely to mothers with preeclampsia

OBJECTIVE

To evaluate the relationship between maternal preeclampsia resulting in premature delivery and adiposity in the offspring during adolescence.

STUDY DESIGN

The 172 study participants were 14 years old and had very low birth weight. We compared height, weight, body mass index (BMI), percent fat, waist circumference, and triceps and subscapular skin fold thicknesses between those born prematurely secondary to preeclampsia (n = 51; 22 male) and those born prematurely after normotensive pregnancies (n = 121; 55 male). Multiple linear regression analysis was used to adjust for potential confounders (maternal BMI, antenatal steroid exposure, and race) and to evaluate potential explanatory variables (fetal, infancy, and childhood weight gain, and caloric intake, level of fitness, and physical activity at 14 years).

RESULTS

When adjusted for potential prenatal confounders (antenatal steroid exposure and race), adolescent male offspring of preeclamptic pregnancies had higher BMI (4.0 kg/m(2) [1.5, 6.6]) (mean difference [95% CI]), waist circumference (11.8 cm [3.8, 19.7]), triceps (4.6 mm [0.6, 8.6]) and subscapular skinfold thicknesses (6.2 mm [1.5, 10.9]), and percent body fat (4.1% [-0.1, 8.3]). Adjusting for infancy and childhood weight gain attenuated these group differences. There were no group differences among females.

CONCLUSION

Male adolescent offspring born prematurely of women with preeclampsia have higher measures of adiposity than those born prematurely of normotensive pregnancies.

Insulin-like growth factor I: could it be a marker of prematurity in the foal?

Insulin-like growth factor (IGF)-I represents one of the most important growth regulators, playing a central role in fetal and neonatal growth. Plasma IGF-I levels increase rapidly after birth, and they are influenced by numerous factors, including sex, age, nutritional state, and premature birth. The aims of this study were: (1) to evaluate the IGF-I plasma profile in healthy newborn foals during the first 2 weeks of life; (2) to assess the possible influence of sex and birth weight on this hormone; (3) to analyze the percentage increment of IGF-I values in healthy foals; (4) to evaluate the influence of prematurity on IGF-I profile; (5) to verify the role of IGF-I as a diagnostic marker of prematurity; and (6) to analyze the percentage increment of IGF-I in premature foals. Thirty-four healthy term foals were enrolled as the control group and from each foal plasma was collected within 6 hours from birth, at 12 hours, daily from Day 1 to Day 7, and at Days 10 and 14 after birth. Eleven foals aged younger than 1 week and diagnosed as premature and hospitalized at a Equine Perinatology Unit were also enrolled; from each foal plasma was collected daily from the day of admission to discharge or death. Insulin-like growth factor I was analyzed by RIA. In the control group, an increasing trend of IGF-I concentrations was found, with higher values from Day 4 to 10 compared with data obtained at less than 6 hours of life, and from Day 5 to 10 compared with 12 and 24 hours and 3 days. No differences were found in healthy foals analyzed in relation to birth weight and sex. In premature foals an increasing trend was observed but no statistical differences were found among sampling times, and no differences were found between healthy and premature foals. The IGF value in premature foals at admission was always higher compared with the lowest recorded level in healthy age-matched foals, thus this parameter does not seem to have a diagnostic role for prematurity in foals. Finally, the evaluation of the percentage increment of IGF-I concentrations showed a significant increase in full-term foals on Day 5, 6, 7, and 10 compared with 12 and 24 hours, and no differences were observed in premature foals. In conclusion, prematurity in newborn foals seems to affect only partially IGF-I plasma concentrations and it does not seem to be a reliable marker for this pathological condition.

Growth factors, adiponectin, leptin and body mass index in pre-pubertal children born large for gestational age

OBJECTIVE

To examine whether the IGF axis in pre-pubertal children born large for gestational age (LGA) differs from that of those born appropriate for gestational age (AGA).

RESEARCH DESIGN AND METHODS

The study population consisted of 98 non-obese children aged 5.5-8 yr, of whom 37 were LGA, with birth weight (BW) > 90th percentile, and 61 AGA. The LGA children were subdivided into two subgroups, with BW 90th-97th percentile (no.=24) and BW > 97th percentile (no.=13), respectively. Total and free IGF-I, their binding proteins 1 and 3 (IGFBP-1 and IGFBP-3), leptin, adiponectin, fasting glucose (GF) and insulin (IF) were measured, and the homeostasis model assessment for insulin resistance (HOMA-IR index) was determined.

RESULTS

IGF-I, free IGF-I and IGFBP-1 were similar in both groups. Both LGA subgroups had lower IGFBP-3 levels than the AGA group (2.34 ± 0.61 and 2.70 ± 0.90, respectively, vs 3.92 ± 1.1 μg/ml, p < 0.01). Adiponectin was higher in the 90th-97th percentile LGA subgroup than the AGA group (p<0.01). GF and IF were higher in the LGA group (86.5 ± 5.6 mg/dl, p < 0.01, and 5.84 ± 2.13 μU/ml, respectively, p < 0.05) than in the AGA group (82.6 ± 7.7 mg/dl and 4.62 ± 1.9 μU/ml, respectively), as was the HOMA-IR index (1.27 ± 0.60 vs 0.94 ± 0.43, p < 0.01). These three parameters were also found higher in the >97th percentile LGA subgroup.

CONCLUSION

The IGF axis was not different in pre-pubertal children born LGA or AGA, with the exception of IGFBP-3, which was lower in the LGA children. In LGA pre-pubertal children the severity of intrauterine overgrowth was associated with the insulin resistance indices.