Physical Growth and Retinopathy in Preterm Infants: Involvement of IGF-I and GH

Hikino, Shunji; Ihara, Kenji; Yamamoto, Jun; Takahata, Yukio; Nakayama, Hideki; Kinukawa, Naoko; Narazaki, Yoko; Hara, Toshiro

doi:10.1203/00006450-200112000-00017

Cited by 55 publications

(24 citation statements)

References 41 publications

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“…Intrauterine IGF-I concentrations increase gradually during pregnancy, but in a more linear pattern (25). Similar findings with low postnatal IGF-I concentrations after preterm birth have been described (11,15,26). Of note, the time point for the postnatal surge in IGF-I concentrations parallelled the beginning of CU in SDS for all growth parameters suggesting an association between these events.…”

Section: Discussionsupporting

confidence: 79%

Influence of Insulin-Like Growth Factor I and Nutrition During Phases of Postnatal Growth in Very Preterm Infants

et al. 2011

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Pronounced growth restriction (GR) occurs after very preterm birth. The interaction between IGF-I, nutritional intake, and growth was evaluated prospectively in 64 infants with a mean (SD) GA of 25.7 (1.9) wk. Blood sampling of IGF-I and measurements of weight, length, and head circumference were performed weekly until discharge. Daily calculation of nutritional intake was performed. Standard deviation scores (SDSs) for growth parameters defined two growth phases: GR phase (birth until lowest SDS) and catch-up (CU) phase (lowest SDS until 35 gestational weeks). IGF-I concentrations during the first postnatal weeks were low and increased at 30 wk GA, irrespective of GA at birth, coinciding with initiation of CU growth. Concentrations of IGF-I were positively associated with change in weight SDS during the GR phase, p ϭ 0.001 and CU phase, p ϭ 0.004 -0.027. Protein and energy intake were not associated with change in SDS weight during the GR phase as opposed to the CU phase (p Ͻ 0.001, respectively). Nutritional intake did not correlate to concentrations of IGF-I before 30 wk GA. IGF-I is associated with growth at an earlier postnatal age than nutrient intake and the effect of nutrition on levels of IGF-I may be restricted to the period of established CU growth. T he maximum growth rate of the fetus is reached in the middle of pregnancy, where it is approximately three times higher than at term (1). Fetal growth rate is to a large extent determined by placental capacity of delivering nutrients to the fetus, whereas genetic influence seems to play a less important role. Placental function depends on the maternal nutritional state and the intrauterine endocrine environment. At preterm birth, the fetal-placental interaction is interrupted, which has an impact on continued extrauterine growth capacity. Postnatal growth retardation occurs almost inevitably after preterm birth and has been associated with decreased brain volumes and impaired neurodevelopmental outcome (2,3). Although attempts are made to optimize postnatal nutritional intakes in preterm infants, these are still commonly suboptimal according to intrauterine requirements (4). Increased postnatal nutritional intake has been shown to improve growth rate in very LBW infants (5), although a recent study could not demonstrate any apparent effect of hyperalimentation on subsequent postnatal growth in very preterm infants (6).IGF-I is an important fetal growth factor, which is essential for the developing brain (7). Concentrations of fetal IGF-I are closely related to placental transfer of glucose where fetal glucose increases insulin secretion, which in turn stimulates fetal IGF-I production (8). Fetal levels of IGF-I may also be regulated by an interaction at the feto-maternal placental interface (9). The disruption of placental nutrient supply after birth is followed by a rapid decrease in postnatal levels of IGF-I, suggesting a low endogenous production (10). While term infants restore their IGF-I levels within the first postnatal weeks, very prete...

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Section: Discussionsupporting

confidence: 79%

Influence of Insulin-Like Growth Factor I and Nutrition During Phases of Postnatal Growth in Very Preterm Infants

et al. 2011

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“…This in contrast to adults, in whom a low dose of GH increases left ventricular mass and an excess of GH is associated with cardiac hypertrophy (39,40). In our GH-treated patients, we did not find an increase in severe ROP, although recent studies suggest an association between the persistence of high GH levels in preterm infants and the development of severe retinopathy (41). Although treatment with GH did not result in a positive effect on growth in the short term, we are planning a long-term follow-up to investigate whether there is any effect on growth, neurodevelopment, and lung function.…”

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confidence: 92%

A Randomized, Placebo-Controlled GH Trial in Very Preterm Infants Who Were at Risk for Bronchopulmonary Dysplasia and Were Treated with Dexamethasone

et al. 2005

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Very preterm infants who develop bronchopulmonary dysplasia are often treated with dexamethasone (DEXA) to wean them from the ventilator. As DEXA has growth-suppressive and catabolic effects, which might have long-term consequences on growth and organ development, we investigated whether high-dose GH treatment could overcome these effects. In a randomized, double-blind, placebo-controlled trial, 30 ventilated very low birth weight infants were assigned to receive either GH or placebo treatment after start of DEXA. DEXA was given for 24 d (starting dose 0.5 mg · kg, tapering off every third day). Simultaneously, high-dose GH (0.3 mg · kg Ϫ1 · d Ϫ1) or placebo was administered during 6 wk. During high-dose DEXA treatment (dose 0.5-0.3 mg · kg Ϫ1 · d Ϫ1), no gain in head circumference, weight, crown-heel length, and knee-heel length occurred in the GH and placebo groups. Growth during the 6-wk study period was not different between the GH and the placebo groups. Two patients in the placebo group died, but the number and the severity of adverse effects was not statistically different between the GH and placebo groups. In conclusion, highdose GH treatment did not improve growth in DEXA-treated very preterm infants and thus cannot be recommended to prevent growth failure in these infants. During high-dose DEXA, a complete growth arrest occurred, including stunting of head growth. Growth in head circumference and weight with lower dose DEXA was comparable to growth after discontinuation of DEXA. In very preterm infants, the development of bronchopulmonary dysplasia (BPD) is a major problem. According to the latest classification, BPD is evaluated at 36 wk postmenstrual age or at discharge from the neonatal intensive care unit (NICU), whichever comes first, and is defined as a persistent need for supplemental oxygen for at least 28 d with a persistence of respiratory features, such as retractions, tachypnea, and rales as a result of respiratory disease (1). The incidence of BPD increases from 12% in infants with a gestational age of 30 wk to 30 -40% in those who are born after a gestational age of 25-26 wk (2,3).In NICUs, systemic corticosteroids are often given to wean very preterm infants with severe and prolonged respiratory problems from the ventilator (4 -6). Many infants who are at risk for development of BPD are treated with dexamethasone (DEXA). DEXA treatment in preterm infants is known to have an inhibiting effect on weight gain as well as linear growth and head circumference (7-11). Follow-up studies suggest impairment in brain growth and persisting growth retardation into childhood (12-16).

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“…It has been suggested that GH may be of importance for angiogenesis (23,24). This is thought to be due to the effect of GH on IGF-1 with decreased GH levels leading to decreased IGF-1 synthesis (23).…”

Section: Discussionmentioning

confidence: 99%

Effects of Brief, Clustered Versus Dispersed Hypoxic Episodes on Systemic and Ocular Growth Factors in a Rat Model of Oxygen-Induced Retinopathy

et al. 2008

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Physical Growth and Retinopathy in Preterm Infants: Involvement of IGF-I and GH

Cited by 55 publications

References 41 publications

Influence of Insulin-Like Growth Factor I and Nutrition During Phases of Postnatal Growth in Very Preterm Infants

Influence of Insulin-Like Growth Factor I and Nutrition During Phases of Postnatal Growth in Very Preterm Infants

A Randomized, Placebo-Controlled GH Trial in Very Preterm Infants Who Were at Risk for Bronchopulmonary Dysplasia and Were Treated with Dexamethasone

Effects of Brief, Clustered Versus Dispersed Hypoxic Episodes on Systemic and Ocular Growth Factors in a Rat Model of Oxygen-Induced Retinopathy

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