Inositol for respiratory distress syndrome in preterm infants

Inositol and vitamin D may naturally protect human reproduction and women undergoing assisted reproduction from Covid-19 risk

In late 2019, the new Coronavirus has been identified in the city of Wuhan then COVID-19 spreads like wildfire in the rest of the world. Pregnant women represent a risk category for increased abortion rates and vertical transmission with adverse events on the newborns has been recently confirmed. The scientific world is struggling for finding an effective cure for counteracting symptomatology. Today, there are many therapeutic proposes but none of them can effectively counteract the infection. Moreover, many of these compounds show important side effects not justifying their use. Scientific literature reports an immune system over-reaction through interleukins-6 activation. In this regard, the possibility to control the immune system represents a possible strategy for counteracting the onset of COVID-19 symptomatology. Vitamin D deficiency shows increased susceptibility to acute viral respiratory infections. Moreover, Vitamin D seems involved in host protection from different virus species by modulating activation and release of cytokines. Myo-inositol down-regulates the expression of IL-6 by phosphatidyl-inositol-3-kinase (PI3K) pathway. Furthermore, myo-inositol is the precursor of phospholipids in the surfactant and it is applied for inducing surfactant synthesis in infants for treating respiratory distress syndrome (RDS). This review aims to summarize the evidence about COVID-19 infection in pregnant women and to encourage the scientific community to investigate the use of Vitamin D and Myo-inositol which could represent a possible preventive treatment for pregnant women or women undergoing assisted reproductive technologies (ART).

Current evidence and outcomes for retinopathy of prematurity prevention: insight into novel maternal and placental contributions

Retinopathy of prematurity (ROP) is a blinding morbidity of preterm infants, which represents a significant clinical problem, accounting for up to 40% of all childhood blindness. ROP displays a range of severity, though even mild disease may result in life-long visual impairment. This is complicated by the fact that our current treatments have significant ocular and potentially systemic effects. Therefore, disease prevention is desperately needed to mitigate the life-long deleterious effects of ROP for preterm infants. Although ROP demonstrates a delayed onset of retinal disease following preterm birth, representing a potential window for prevention, we have been unable to sufficiently alter the natural disease course and meaningfully prevent ROP. Prevention therapeutics requires knowledge of early ROP molecular changes and risk, occurring prior to clinical retinal disease. While we still have an incomplete understanding of these disease mechanisms, emerging data integrating contributions of maternal/placental pathobiology with ROP are poised to inform novel approaches to prevention. Herein, we review the molecular basis for current prevention strategies and the clinical outcomes of these interventions. We also discuss how insights into early ROP pathophysiology may be gained by a better understanding of maternal and placental factors playing a role in preterm birth.

Inositol in preterm infants at risk for or having respiratory distress syndrome

BACKGROUND

Inositol is an essential nutrient required by human cells in culture for growth and survival. Inositol promotes maturation of several components of surfactant and may play a critical role in fetal and early neonatal life. A drop in inositol levels in infants with respiratory distress syndrome (RDS) can be a sign that their illness will be severe.

OBJECTIVES

To assess the effectiveness and safety of supplementary inositol in preterm infants with or without respiratory distress syndrome (RDS) in reducing adverse neonatal outcomes including: death (neonatal and infant deaths), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), necrotizing enterocolitis (NEC) and sepsis.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 11), MEDLINE via PubMed (1966 to 5 November 2018), Embase (1980 to 5 November 2018), and CINAHL (1982 to 5 November 2018). We searched clinical trial databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials (RCT) and quasi-randomised trials.

SELECTION CRITERIA

We included all randomised controlled trials of inositol supplementation of preterm infants compared with a control group that received a placebo or no intervention. Outcomes included neonatal death, infant death, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC) and sepsis.

DATA COLLECTION AND ANALYSIS

The three review authors independently abstracted data on neonatal outcomes and resolved any disagreements through discussion and consensus. Outcomes were reported as typical risk ratio (RR), risk difference (RD) and number needed to treat for an additional beneficial outcome (NNTB) or number needed to treat for an additional harmful outcome (NNTH). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

Six published randomised controlled trials were identified, with a total of 1177 infants. Study quality varied for the comparison 'Inositol supplementation to preterm infants (repeat doses in any amount and any duration of treatment) versus control' and interim analyses had occurred in several trials for the outcomes of interest. In this comparison, neonatal death was found to be significantly reduced (typical RR 0.53, 95% CI 0.31 to 0.91; typical RD -0.09, 95% CI -0.16 to -0.01; NNTB 11, 95% CI 6 to 100; 3 trials, 355 neonates). Infant deaths were not reduced (typical RR 0.89, 95% CI 0.71 to 1.13; typical RD -0.02, 95% CI -0.07 to 0.02; 5 trials, 1115 infants) (low-quality evidence). ROP stage 2 or higher or stage 3 or higher was not significantly reduced (typical RR 0.89, 95% CI 0.75 to 1.06; typical RD -0.04, 95% CI -0.10 to 0.02; 3 trials, 810 infants) (moderate-quality evidence). There were no significant findings for ROP (any stage), NEC (suspected or proven), sepsis, IVH grade greater than II (moderate-quality evidence). For the comparison 'Inositol supplementation IV initially followed by enteral administration (repeat doses of 80 mg/kg/day) in preterm infants born at less than 30 weeks' postmenstrual age (PMA) compared to placebo for preterm infants at risk for or having respiratory distress syndrome' the results from two studies of high quality were included (N = 760 neonates). Recruitment to the larger study (N = 638) was terminated because of a higher rate of deaths in the inositol group. We did not downgrade the quality of the study. The meta-analyses of the outcomes of 'Type 1 ROP or death before determination of ROP outcome using the adjudicated ROP outcome', 'Type 1 ROP including adjudicated ROP outcome', 'All-cause mortality (outcome collected through first event: death, hospital discharge, hospital transfer, or 120 days after birth)' and 'Severe IVH (grade 3 or 4)' did not show significant findings (moderate-quality evidence). There were no significant findings for the outcomes 'BPD or death by it prior to 37 weeks' postmenstrual age (outcomes collected through first event: death, hospital discharge, hospital transfer, or 120 days after birth)', 'Late onset sepsis (> 72 hours of age)', and 'Suspected or proven NEC' (high-quality evidence).

AUTHORS' CONCLUSIONS

Based on the evidence from randomised controlled trials to date, inositol supplementation does not result in important reductions in the rates of infant deaths, ROP stage 3 or higher, type 1 ROP, IVH grades 3 or 4, BPD, NEC, or sepsis. These conclusions are based mainly on two recent randomised controlled trials in neonates less than 30 weeks' postmenstrual age (N = 760), the most vulnerable population. Currently inositol supplementation should not be routinely instituted as part of the nutritional management of preterm infants with or without RDS. It is important that infants who have been enrolled in the trials included in this review are followed to assess any effects of inositol supplementation on long-term outcomes in childhood. We do not recommend any additional trials in neonates.

Effects of Myo-inositol on Type 1 Retinopathy of Prematurity Among Preterm Infants <28 Weeks' Gestational Age: A Randomized Clinical Trial

IMPORTANCE

Previous studies of myo-inositol in preterm infants with respiratory distress found reduced severity of retinopathy of prematurity (ROP) and less frequent ROP, death, and intraventricular hemorrhage. However, no large trials have tested its efficacy or safety.

OBJECTIVE

To test the adverse events and efficacy of myo-inositol to reduce type 1 ROP among infants younger than 28 weeks' gestational age.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial included 638 infants younger than 28 weeks' gestational age enrolled from 18 neonatal intensive care centers throughout the United States from April 17, 2014, to September 4, 2015; final date of follow-up was February 12, 2016. The planned enrollment of 1760 participants would permit detection of an absolute reduction in death or type 1 ROP of 7% with 90% power. The trial was terminated early due to a statistically significantly higher mortality rate in the myo-inositol group.

INTERVENTIONS

A 40-mg/kg dose of myo-inositol was given every 12 hours (initially intravenously, then enterally when feeding; n = 317) or placebo (n = 321) for up to 10 weeks.

MAIN OUTCOMES AND MEASURES

Type 1 ROP or death before determination of ROP outcome was designated as unfavorable. The designated favorable outcome was survival without type 1 ROP.

RESULTS

Among 638 infants (mean, 26 weeks' gestational age; 50% male), 632 (99%) received the trial drug or placebo and 589 (92%) had a study outcome. Death or type 1 ROP occurred more often in the myo-inositol group vs the placebo group (29% vs 21%, respectively; adjusted risk difference, 7% [95% CI, 0%-13%]; adjusted relative risk, 1.41 [95% CI, 1.08-1.83], P = .01). All-cause death before 55 weeks' postmenstrual age occurred in 18% of the myo-inositol group and in 11% of the placebo group (adjusted risk difference, 6% [95% CI, 0%-11%]; adjusted relative risk, 1.66 [95% CI, 1.14-2.43], P = .007). The most common serious adverse events up to 7 days of receiving the ending dose were necrotizing enterocolitis (6% for myo-inositol vs 4% for placebo), poor perfusion or hypotension (7% vs 4%, respectively), intraventricular hemorrhage (10% vs 9%), systemic infection (16% vs 11%), and respiratory distress (15% vs 13%).

CONCLUSIONS AND RELEVANCE

Among premature infants younger than 28 weeks' gestational age, treatment with myo-inositol for up to 10 weeks did not reduce the risk of type 1 ROP or death vs placebo. These findings do not support the use of myo-inositol among premature infants; however, the early termination of the trial limits definitive conclusions.

Amniotic Fluid and Maternal Serum Metabolic Signatures in the Second Trimester Associated with Preterm Delivery

Preterm delivery (PTD) represents a major health problem that occurs in 1 in 10 births. The hypothesis of the present study was that the metabolic profile of different biological fluids, obtained from pregnant women during the second trimester of gestation, could allow useful correlations with pregnancy outcome. Holistic and targeted metabolomics approaches were applied for the complementary assessment of the metabolic content of prospectively collected amniotic fluid (AF) and paired maternal blood serum samples from 35 women who delivered preterm (between 29 weeks + 0 days and 36 weeks +5 days gestation) and 35 women delivered at term. The results revealed trends relating the metabolic content of the analyzed samples with preterm delivery. Untargeted and targeted profiling showed differentiations in certain key metabolites in the biological fluids of the two study groups. In AF, intermediate metabolites involved in energy metabolism (pyruvic acid, glutamic acid, and glutamine) were found to contribute to the classification of the two groups. In maternal serum, increased levels of lipids and alterations of key end-point metabolites were observed in cases of preterm delivery. Overall, the metabolic content of second-trimester AF and maternal blood serum shows potential for the identification of biomarkers related to fetal growth and preterm delivery.

Working group reports: evaluation of the evidence to support practice guidelines for nutritional care of preterm infants-the Pre-B Project

The "Evaluation of the Evidence to Support Practice Guidelines for the Nutritional Care of Preterm Infants: The Pre-B Project" is the first phase in a process to present the current state of knowledge and to support the development of evidence-informed guidance for the nutritional care of preterm and high-risk newborn infants. The future systematic reviews that will ultimately provide the underpinning for guideline development will be conducted by the Academy of Nutrition and Dietetics' Evidence Analysis Library (EAL). To accomplish the objectives of this first phase, the Pre-B Project organizers established 4 working groups (WGs) to address the following themes: 1) nutrient specifications for preterm infants, 2) clinical and practical issues in enteral feeding of preterm infants, 3) gastrointestinal and surgical issues, and 4) current standards of infant feeding. Each WG was asked to 1) develop a series of topics relevant to their respective themes, 2) identify questions for which there is sufficient evidence to support a systematic review process conducted by the EAL, and 3) develop a research agenda to address priority gaps in our understanding of the role of nutrition in health and development of preterm/neonatal intensive care unit infants. This article is a summary of the reports from the 4 Pre-B WGs.

Inositol in preterm infants at risk for or having respiratory distress syndrome

BACKGROUND

Inositol is an essential nutrient required by human cells in culture for growth and survival. Inositol promotes maturation of several components of surfactant and may play a critical role in fetal and early neonatal life.

OBJECTIVES

To assess the effectiveness and safety of supplementary inositol in preterm infants with or without respiratory distress syndrome (RDS) in reducing adverse neonatal outcomes.

SEARCH METHODS

The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, CINAHL, Clinicaltrials.gov and Controlled-trials.com were searched in September 2014. The reference lists of identified randomised controlled trials (RCTs), personal files and Web of Science were searched.

SELECTION CRITERIA

All RCTs of inositol supplementation of preterm infants compared with a control group that received a placebo or no intervention were included. Outcomes of interest were neonatal death, infant death, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC) and sepsis.

DATA COLLECTION AND ANALYSIS

Data on neonatal outcomes were abstracted independently by the three review authors and any discrepancy was resolved through consensus. Outcomes were reported as relative risk (RR), risk difference (RD) and number needed to treat to benefit (NNTB) or to harm (NNTH).

MAIN RESULTS

Four published RCTs and one ongoing RCT were identified. Study quality varied and interim analyses had occurred in all trials of repeat doses of inositol that provided data for the outcomes of interest in this review. In these trials neonatal death was found to be significantly reduced (3 trials, 355 neonates; typical RR 0.53, 95% CI 0.31 to 0.91; typical RD -0.09, 95% CI -0.17 to -0.03; NNTB 11, 95% CI 6 to 33). Infant deaths were reduced (3 trials, 355 infants; typical RR 0.55, 95% CI 0.40 to 0.77; typical RD -0.18, 95% CI -0.27 to -0.08; NNTB 6, 95% CI 4 to 13). ROP stage ≥ 3 was significantly reduced (2 trials, 262 infants; typical RR 0.09, 95% CI 0.01 to 0.67; typical RD -0.08, 95% CI -0.13 to -0.03; NNTB 13, 95% CI 8 to 33) and IVH grade > II was significantly decreased (3 trials, 355 infants; typical RR 0.53, 95% CI 0.31 to 0.90; typical RD -0.09, 95% CI -0.16 to -0.02; NNTB 11, 95% CI 6 to 50). Neither sepsis nor NEC differed significantly between groups. One study (74 infants) that administered a single dose of inositol (60 or 120 mg/kg) found no significant differences in adverse outcomes using RR, but an increased RD for BPD at 36 weeks postmenstrual age (RD 0.23, 95% CI 0.03 to 0.43; NNTH 4, 95% CI 2 to 33). This result should be interpreted with caution as only one dose of inositol was given and only the RD, but not the RR, was significant. One ongoing large study of repeat doses of inositol in preterm infants was identified.

AUTHORS' CONCLUSIONS

Inositol supplementation results in statistically significant and clinically important reductions in important short-term adverse neonatal outcomes. A large size multi-centre randomised controlled trial is currently ongoing and the trial will likely confirm or refute the findings from this systematic review.

Bronchopulmonary dysplasia: NHLBI Workshop on the Primary Prevention of Chronic Lung Diseases

Bronchopulmonary dysplasia (BPD) is the most common complication of extreme preterm birth. Infants who develop BPD manifest aberrant or arrested pulmonary development and can experience lifelong alterations in cardiopulmonary function. Despite decades of promising research, primary prevention of BPD has proven elusive. This workshop report identifies current barriers to the conduct of primary prevention studies for BPD and causal pathways implicated in BPD pathogenesis. Throughout, we highlight promising areas for research to improve understanding of normal and aberrant lung development, distinguish BPD endotypes, and ascertain biomarkers for more targeted therapeutic approaches to prevention. We conclude with research recommendations and priorities to accelerate discovery and promote lung health in infants born preterm.

Pharmacokinetics and safety of a single intravenous dose of myo-inositol in preterm infants of 23-29 wk

BACKGROUND

Myo-inositol given to preterm infants with respiratory distress has reduced death, increased survival without bronchopulmonary dysplasia, and reduced severe retinopathy of prematurity in two randomized trials. Pharmacokinetic (PK) studies in extremely preterm infants are needed before efficacy trials.

METHODS

Infants born in 23-29 wk of gestation were randomized to a single intravenous (i.v.) dose of inositol at 60 or 120 mg/kg or placebo. Over 96 h, serum levels (sparse sampling population PK) and urine inositol excretion were determined. Population PK models were fit using a nonlinear mixed-effects approach. Safety outcomes were recorded.

RESULTS

A single-compartment model that included factors for endogenous inositol production, allometric size based on weight, gestational age strata, and creatinine clearance fit the data best. The central volume of distribution was 0.5115 l/kg, the clearance was 0.0679 l/kg/h, endogenous production was 2.67 mg/kg/h, and the half-life was 5.22 h when modeled without the covariates. During the first 12 h, renal inositol excretion quadrupled in the 120 mg/kg group, returning to near-baseline value after 48 h. There was no diuretic side effect. No significant differences in adverse events occurred among the three groups (P > 0.05).

CONCLUSION

A single-compartment model accounting for endogenous production satisfactorily described the PK of i.v. inositol.

Retinopathy of prematurity

The immature retinas of preterm neonates are susceptible to insults that disrupt neurovascular growth, leading to retinopathy of prematurity. Suppression of growth factors due to hyperoxia and loss of the maternal-fetal interaction result in an arrest of retinal vascularisation (phase 1). Subsequently, the increasingly metabolically active, yet poorly vascularised, retina becomes hypoxic, stimulating growth factor-induced vasoproliferation (phase 2), which can cause retinal detachment. In very premature infants, controlled oxygen administration reduces but does not eliminate retinopathy of prematurity. Identification and control of factors that contribute to development of retinopathy of prematurity is essential to prevent progression to severe sight-threatening disease and to limit comorbidities with which the disease shares modifiable risk factors. Strategies to prevent retinopathy of prematurity will depend on optimisation of oxygen saturation, nutrition, and normalisation of concentrations of essential factors such as insulin-like growth factor 1 and ω-3 polyunsaturated fatty acids, as well as curbing of the effects of infection and inflammation to promote normal growth and limit suppression of neurovascular development.

Nutrition, insulin-like growth factor-1 and retinopathy of prematurity

Retinopathy of prematurity is a potentially blinding disease starting with impaired retinal vessel growth in the neonatal period. Weeks to months later, peripheral retinal hypoxia induces pathologic neovascularization that may lead to retinal detachment and blindness. Current treatment strategies target late stage disease and it would be advantageous if retinopathy of prematurity could be prevented. Poor general growth after very preterm birth is a universal problem associated with increased risk of retinopathy. Loss of the maternal-fetal interaction results not only in loss of nutrients but also of other factors provided in utero. The importance of nutrition and factors such as insulin-like growth factor-1 and ω-3 long chain fatty acids for proper retinal vascularization has been defined in animal studies. Increasing evidence of the applicability of these findings to human infants is accumulating. This review focuses on factors essential for neonatal growth and possible strategies to improve growth and prevent retinopathy.

Reporting 'number needed to treat' in meta-analyses: a cross-sectional study

AIM

In translating clinical research into practice, the summarization of data from randomized trials in terms of measures of effect to be readily appreciated by the point-of-care clinicians is important. In this context, the body of literature highlighted the 'number needed to treat' as a useful measure. The objectives of our study were to assess how meta-analyses described number needed to treat and corresponding 95% CI, and to explore issues related to reporting number needed to treat in the selected meta-analyses.

METHOD

For an illustration, we searched for the Cochrane systematic reviews and non-Cochrane systematic reviews. Two-stage selection was done to identify eligible studies. First, we fixed a date and then, we searched meta-analyses in PUBMED available on the date fixed. Secondly, we purposively selected five Cochrane systematic reviews and three non-Cochrane systematic reviews, according to our inclusion criteria. The critical appraisal of meta-analyses identified for the current study was done with the 5-item quality checklist introduced to the current analysis.

RESULTS

A total of 8 systematic reviews, 5 Cochrane systematic reviews and 3 non-Cochrane systematic reviews/meta-analyses, were identified for the present study. Of these 8 meta-analyses, some (50%; 4/8) described number needed to treat in the method session of the study. However, the majority (87.5%; 7/8) reported number needed to treat in the results. For the details, 80% in Cochrane reviews and 66.5% in non-Cochrane reviews reported number needed to treat in the results. Only two studies (25%; 2/8) reported susceptibility to publication bias, provided simplified interpretation or discussed number needed to treat.

CONCLUSION

Although the Cochrane handbook for systematic reviews of interventions suggests the reviewers to include number needed to treat in reporting effect estimations, there still is a need to improve.

Infant formulas for preterm infants: in-hospital and post-discharge

The availability and composition of preterm and post-discharge formulas (PDFs) have undergone considerable changes over the last decade. Human milk, supplemented with multi-component fortifier, is the preferred feed for very preterm infants as it has beneficial effects for both short- and long-term outcomes compared with formula. If supply of mother's milk or donor milk is inadequate, a breast milk substitute specifically designed for premature infants is the next option. Preterm formula is intended to provide nutrient intakes to match intrauterine growth and nutrient accretion rates and is enriched with energy, macronutrients, minerals, vitamins, and trace elements compared with term infant formulas. Post-natal longitudinal growth failure has been reported almost universally in extremely preterm infants. Since 2009, a nutritionally enriched PDF specifically designed for preterm infants post hospital discharge with faltering growth has been available in Australia and New Zealand. This formula is an intermediary between preterm and term formulas and contains more energy (73 kcal/100 mL), protein (1.9 g/100 mL), minerals, vitamins, and trace elements than term formulas. Although the use of a PDF is based on sound nutritional knowledge, the 2012 Cochrane Systematic Review of 10 trials comparing feeding preterm infants with PDF and term formula did not demonstrate any short- or long-term benefits. Health professionals need to make individual decisions on whether and how to use PDF.