Impact of insulin resistance on insulin-like growth factor-1/insulin like growth factor-binding protein-3 axis and on early weight gain in small for gestational age infants

International Consensus Guideline on Small for Gestational Age (SGA): Etiology and Management from Infancy to Early Adulthood

This International Consensus Guideline was developed by experts in the field of SGA of 10 pediatric endocrine societies worldwide. A consensus meeting was held and 1300 articles formed the basis for discussions. All experts voted about the strengths of the recommendations. The guideline gives new and clinically relevant insights into the etiology of short stature after SGA birth, including novel knowledge about (epi)genetic causes. Besides, it presents long-term consequences of SGA birth and new treatment options, including treatment with gonadotropin-releasing hormone agonist (GnRHa) in addition to growth hormone (GH) treatment, and the metabolic and cardiovascular health of young adults born SGA after cessation of childhood-GH-treatment in comparison with appropriate control groups. To diagnose SGA, accurate anthropometry and use of national growth charts are recommended. Follow-up in early life is warranted and neurodevelopment evaluation in those at risk. Excessive postnatal weight gain should be avoided, as this is associated with an unfavorable cardio-metabolic health profile in adulthood. Children born SGA with persistent short stature < -2.5 SDS at age 2 years or < -2 SDS at age of 3-4 years, should be referred for diagnostic work-up. In case of dysmorphic features, major malformations, microcephaly, developmental delay, intellectual disability and/or signs of skeletal dysplasia, genetic testing should be considered. Treatment with 0.033-0.067 mg GH/kg/day is recommended in case of persistent short stature at age of 3-4 years. Adding GnRHa treatment could be considered when short adult height is expected at pubertal onset. All young adults born SGA require counseling to adopt a healthy lifestyle.

Percentile-Based Reference Values of Umbilical Cord Blood Insulin-like Growth Factor 1 in Japanese Newborns

We aimed to create percentile-based reference values of the umbilical cord blood insulin-like growth factor-1 (IGF-1) levels in Japanese newborns, as these values have not yet been established. A total of 259 newborns were classified into four gestational-age-at-birth (GA) groups: extremely preterm (<28 weeks); early preterm (28−33 weeks); late preterm (34−36 weeks); and term (≥37 weeks). They were further subclassified as small-for-gestational-age (SGA) or non-SGA. The 10th, 25th, 50th, 75th, and 90th percentiles of the umbilical cord blood IGF-1 levels were calculated and compared between the groups by using reference values of 9, 18, 33, 52, and 71 ng/mL, respectively. In the extremely preterm group, the IGF-1 levels were significantly lower than those in the early preterm, late preterm, and term groups (13.5, 24.0, 44.5, and 47.5 ng/mL, respectively; p < 0.001). The umbilical cord blood IGF-1 levels in the SGA newborns were significantly lower than those in the non-SGA newborns in all subgroups. In multivariate analyses, the GA and birth weight standard deviation scores were independent determinant factors for the umbilical cord blood IGF-1 levels. Thus, we established percentile-based reference values of umbilical cord blood IGF-1 in Japanese newborns; these reference values can be applied on the basis of the extent of prematurity and the SGA status.

First year metabolic and hormonal behaviour define two different populations of SGA newborn for weight or height

Context

Small for gestational age (SGA) children have a particular metabolic and hormonal pattern at birth that change rapidly.

Objective

To evaluate the linear and weight growth in the first year of life in SGA children.

Design

Prospective, monocentric cohort study.

Setting

Real-world data collected from April 2012 to January 2016.

Patients

SGA newborns uniformly defined by either growth or length lower than -2 standard deviation for gestational age.

Interventions

All children were evaluated for one year after birth, at three days of life, then three, six and 12 months after birth.

Main outcome measures

Anthropometric parameters and biochemical variables, such as blood glucose, insulin, leptin, insulin-like growth factor (IGF)-1, IGF binding protein (IGFBP)3, and HOMA index.

Results

One hundred and thirty-three SGA children were enrolled. Length significantly improved one month after birth, whereas weight significantly increased only three months after birth. Biochemical variables increased during the first year of life, showing a prediction by IGFBP-3 and HOMA-index. Then, the casuistry was divided considering either weight, length or both, showing a different incidence. The biochemical variables changes recorded in the first step were maintained considering SGA children for weight or length, whereas they disappeared when weight and length were considered together.

Conclusions

Our study shows a specific catch-up growth for weight and length in SGA children. Moreover, we highlight that weight and length should be considered as independent parameters in SGA children, defining two different metabolic-hormonal populations with different conceivable predictive role in early catch-up growth and in later growth and metabolic status.

Insulin resistance biomarkers in small-for-gestational-age infants born to mothers with gestational diabetes mellitus

OBJECTIVE

Early alterations in glucose homeostasis increase the risk of developing insulin resistance (IR) and obesity later in life. The study aimed to ascertain the peripheral blood levels of hormones that controlling glucose homeostasis and inflammatory factors that are correlated with IR and fetal outcomes in small-for-gestational-age (SGA) infants born to mothers with gestational diabetes mellitus (GDM).

METHODS

This cohort study included a total of 90 SGA infants born to mothers with GDM (n = 37) and without GDM (n = 53). At birth, blood levels of glucose, insulin, C-peptide, growth hormone (GH), IGFBP3, lipid profiles, fibrinogen, and hypersensitive C-reactive protein (Hs-CRP) were measured; homeostatic model assessment-IR (HOMA-IR) and ponderal index were calculated. All newborns were followed up to the first year of life.

RESULTS

Compared with SGA infants born to mothers without GDM, the levels of low-density lipoprotein-cholesterol (LDL-C), GH, and fibrinogen were significantly higher in the SGA infants born to mothers with GDM (p = .048, .045, and .04, respectively). However, total cholesterol, HDL-C, and apolipoprotein(a) levels were significantly lower in the SGA infants born to mothers with GDM when compared with those in with SGA infants born to mothers without GDM (all p < .05). Weight gain in the first year was higher in the SGA infants born to mothers with GDM group than SGA infants born to mothers without GDM [6644 g (5991-7572) vs. 6032 g (5529-6932)].

CONCLUSIONS

Altered biomarkers of IR were observed among SGA infants born to mothers with GDM, suggesting that these infants were more prone to develop IR after birth.

Low-birth-weight, but not catch-up growth, correlates with insulin resistance and resistin level in SGA infants at 12 months

OBJECTIVE

To investigate the insulin resistance status in SGA infants at 12 months and its relationship with auxological and metabolic parameters.

METHODS

One group of 45 SGA and one of 50 appropriate for gestational age infants were followed from birth to the end of the first year of life. At 12 months, skinfold thickness, waist circumference, and blood levels of glucose, insulin, adiponectin, leptin, resistin, visfatin, retinol-binding protein 4, IGFs, lipids profile were determined, and the HOMA-IR index was calculated.

RESULTS

The SGAs had increased insulin (5.2 ± 2.7 versus 2.9 ± 2.4 μIU/ml, p = 0.012) and HOMA-IR (1.09 ± 0.9 versus 0.59 ± 0.55, p = 0.016). In multiple regression, insulin resistance indices were independently correlated with low-birth-weight (β = -2.92, p = 0.015 for insulin, β = -2.98, p = 0.011 for HOMA-IR) but not with catch-up growth in either height or weight or any other metabolic parameter. Resistin was higher in the SGAs (5.1 ± 2.1 versus 3.9 ± 2.1 ng/ml, p = 0.03) and independently correlated with low-birth-weight but not insulin resistance. Resistin was negatively correlated with total cholesterol (R = -0.33, p = 0.007) and positively with lipoprotein(a) (R = 0.49, p = 0.001).

CONCLUSION

Low-birth-weight, but not catch-up growth or adiposity tissue hormones, was correlated with insulin resistance at 12 months in non-obese SGA infants. The higher resistin in SGA infants and its correlation with total cholesterol and lipoprotein(a) need further clarification.

Ghrelin, insulin-like growth factor I and adipocytokines concentrations in born small for gestational age prepubertal children after the catch-up growth

BACKGROUND

In children born small for gestational age (SGA) with catch-up growth, a higher risk of insulin resistance (IR) and cardiovascular diseases is noted. Ghrelin stimulates a growth hormone (GH) secretion and regulates lipid and carbohydrate metabolism. We assessed gherlin's influence on achieving normal height and the occurrence of metabolic complications in SGA children.

METHODS

Ghrelin, insulin-like growth factor type I (IGF-I), leptin, adiponectin, resistin, glucose, insulin and lipid concentrations were analysed in 134 prepubertal children in four groups: normal-height SGA, short SGA, normal-height born appropriate for gestational age (AGA) and short AGA.

RESULTS

Ghrelin and IGF-I concentrations were significantly higher while adiponectin - lower in normal-height SGA comparing to others.

CONCLUSIONS

The increased production of ghrelin and IGF-I seems to be an adaptive mechanism to achieve normal growth in SGA children. The significance of high ghrelin and low adiponectin concentrations, observed in normal-height prepubertal SGA children, requires elucidation, with reference to the development of metabolic complications.

Maternal nutritional history modulates the hepatic IGF-IGFBP axis in adult male rat offspring

Alterations in early life nutrition lead to an increased risk of obesity and metabolic syndrome in offspring. We have shown that both relative maternal undernutrition (UN) and maternal obesity result in metabolic derangements in offspring, independent of the postnatal dietary environment. Since insulin-like growth factor binding protein 2 (IGFBP2) has been shown to be independently associated with obesity and diabetes risk, we examined the IGF-IGFBP axis in male rat offspring following either maternal UN or maternal obesity to explain possible common pathways in the development of metabolic disorders. Wistar rats were time-mated and fed either a control diet (CONT), 50 % of CONT (UN) or a high-fat (HF) diet throughout pregnancy. Male offspring were weaned onto a standard chow diet and blood and tissues were collected at postnatal day 160. Plasma and hepatic tissue samples were analysed for key players in the IGF-IGFBP system. Both maternal UN and HF resulted in increased fat mass, hyperinsulinemia, hyperleptinemia and altered blood lipid profiles in offspring compared to CONT. Circulating IGF-1 and IGFBP3 levels and hepatic mRNA expression of IGFBP1 and IGFBP2 were significantly decreased in UN and HF offspring compared to CONT. DNA methylation of the IGFBP2 promotor region was similar between maternal dietary groups. Although chaperone gene heat-shock protein 90 and hepatic IGFBP1 were significantly correlated in CONT offspring this effect was absent in both UN and HF offspring. In conclusion, this study is one of the first to directly compare two experimental models of developmental programming representing both ends of the maternal dietary spectrum. Our data suggest that two disparate nutritional models that elicit similar adverse metabolic phenotypes in offspring are characterised by common alterations in the IGF-IGFBP pathway.