Effect of zinc supplementation on morbidity and growth in hospital-born, low-birth-weight infants

Zinc Supplementation in Very Low Birth Weight Infants: A Randomized Controlled Trial

OBJECTIVE

 Preterm infants have high zinc (Zn) requirements and are generally believed to be in a negative Zn balance in the early period of life. In this study, we aimed to investigate the effect of high-dose Zn supplementation in very low birth weight (VLBW: infants with birth weight < 1.5 kg) infants on feeding intolerance and development of mortality and/or morbidities including necrotizing enterocolitis (NEC) and late-onset sepsis (LOS).

STUDY DESIGN

 This is a prospective randomized trial. VLBW preterm infants with gestational age of <32 weeks were randomly allocated on the seventh day of life to receive extra amount of supplemental Zn along with the enteral feedings (9 + 3 mg), besides regular low-dose supplementation (3 mg), from enrollment until discharge. Outcome measures were feeding intolerance, NEC (stage ≥ 2), LOS, and mortality.

RESULTS

 A total of 195 infants (97 from study group and 98 from control group) were analyzed. A total of 46 (47.4%) infants in the study group and 64 (65.3%) infants in the control group ended up with feeding intolerance (p = 0.012). NEC was observed in 11 infants (11.2%) in the control group and only 1 infant (1%) in the study group (p = 0.003). There was a negative correlation between high-dose Zn supplementation and number of culture-proven LOS episodes (p = 0.041). This significance was also present for clinical sepsis, being higher in the control group (p = 0.029). No relationship between high-dose Zn supplementation and mortality and other morbidities (hemodynamically significant patent ductus arteriosus, bronchopulmonary dysplasia, retinopathy of prematurity, and severe intraventricular hemorrhage) was observed.

CONCLUSION

 Zn supplementation for VLBW infants is found to be effective to decrease feeding intolerance, NEC, and LOS episodes in this vulnerable population. Current data support the supplementation of VLBW infants with higher than regular dose of Zn.

KEY POINTS

· Higher dose of Zn supplementation is shown to be a beneficial intervention in VLBW infants.. · Zn may decrease feeding intolerance, sepsis or NEC.. · Higher than regular dose of Zn seems to be safe..

Enteral Zinc Supplementation in Preterm or Low Birth Weight Infants: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Evidence on the effect of zinc supplementation on health outcomes in preterm or low birth weight (LBW) infants is unclear. We estimated the effect of enteral zinc versus no zinc supplementation in human milk fed preterm or LBW infants on mortality, growth, morbidities, and neurodevelopment.

METHODS

Data sources include PubMed, Cochrane Central and Embase databases through March 24, 2021. Study selection was randomized or quazi-experimental trials. Two reviewers independently screened, extracted data, and assessed quality. We reported pooled relative risks (RR) for categorical outcomes, and mean differences (MD) for continuous outcomes.

RESULTS

Fourteen trials with 9940 preterm or LBW infants were included. Moderate to low certainty evidence showed that enteral zinc supplementation had little or no effect on mortality (risk ratio 0.73, 95% confidence interval [CI] 0.46 to 1.16), but increased weight (MD 378.57, 95% CI 275.26 to 481.88), length (MD 2.92, 95% CI 1.53 to 4.31), head growth (MD 0.56, 95% CI 0.23 to 0.90), and decreased diarrhea (RR 0.81; 95% CI 0.68 to 0.97). There was no effect on acute respiratory infections, bacterial sepsis, and psychomotor development scores. The effect of zinc supplementation on mental development scores is inconclusive. There was no evidence of serious adverse events. Eight trials had some concerns or high risk of bias, small-sized studies, and high heterogeneity between trials led to moderate to very low certainty of evidence.

CONCLUSIONS

Zinc supplementation in preterm or LBW infants have benefits on growth and diarrhea prevention. Further research is needed to generate better quality evidence.

Reconsidering the Tolerable Upper Levels of Zinc Intake among Infants and Young Children: A Systematic Review of the Available Evidence

Safe upper levels (UL) of zinc intake for children were established based on either (1) limited data from just one study among children or (2) extrapolations from studies in adults. Resulting ULs are less than amounts of zinc consumed by children in many studies that reported benefits of zinc interventions, and usual dietary zinc intakes often exceed the UL, with no apparent adverse effects. Therefore, existing ULs may be too low. We conducted a systematic bibliographic review of studies among preadolescent children, in which (1) additional zinc was provided vs. no additional zinc provided, and (2) the effect of zinc on serum or plasma copper, ceruloplasmin, ferritin, transferrin receptor, lipids, or hemoglobin or erythrocyte super-oxide dismutase were assessed. We extracted data from 44 relevant studies with 141 comparisons. Meta-analyses found no significant overall effect of providing additional zinc, except for a significant negative effect on ferritin (p = 0.001), albeit not consistent in relation to the zinc dose. Interpretation is complicated by the significant heterogeneity of results and uncertainties regarding the physiological and clinical significance of outcomes. Current zinc ULs should be reassessed and potentially revised using data now available for preadolescent children and considering challenges regarding interpretation of results.

Effect of zinc supplementation on mortality in under 5-year children: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Several clinical trials evaluated the effect of zinc supplementation on mortality in children, but the results were inconsistent. We aimed to conduct a systematic review and meta-analysis on the impact of zinc supplementation on mortality in under 5-year children.

METHODS

A comprehensive search was conducted using the electronic (PubMed, Scopus, Web of Science) databases, and Google Scholar, up to June 2020. Randomized clinical trials (RCTs) that reported the effect of zinc supplementation on death incidence in under 5-year children were included in the analysis. Screening was performed based on title/abstract and full-text. A random effects model was applied to calculate the summary relative risk (SRR). Risk of Bias 2.0 tool was used to rate the quality of trials. The body of evidence was assessed by the GRADE approach.

RESULTS

Combining 30 RRs from 28 RCTs including 237,068 participants revealed that zinc supplementation has significantly reduced the risk of all-causes mortality by 16% in children (SRR: 0.84, 95% CI: 0.74, 0.96). A follow-up duration of less than 1 year after supplementation resulted in 54% reduced risk of mortality (0.46; 0.33, 0.63) with no heterogeneity between investigations. Subgroup analysis by zinc dosage showed that assigning ≥ 10 mg/d zinc to under five children and duration of less than 11 months of intervention decreased the risk of all-cause mortality by 44% (0.56; 0.42, 0.75) and 48% (0.52; 0.38, 0.72), respectively. In low birth weight (LBW) infants, zinc supplementation was reduced all-cause mortality by 52% (0.48; 0.23, 1.00). Zinc supplementation significantly reduced the risk of death from pneumonia (0.70: 0.64, 0.98) and infection (0.54; 0.39, 0.76), also changed the risk of mortality from diarrhea by 15% (0.85; 0.70, 1.03) and sepsis by 57% (0.43; 0.18, 1.02).

CONCLUSION

This meta-analysis on RCTs revealed that zinc supplementation in under 5-year children has significantly reduced the risk of all-cause mortality. Notable decreases were found in trials with a dose of 10 mg/d or more zinc supplementation, a maximum of 11 months of supplementation, a follow-up less than one year and especially in LBW infants.

Role of zinc in neonatal growth and brain growth: review and scoping review

This manuscript includes (1) a narrative review of Zinc as an essential nutrient for fetal and neonatal growth and brain growth and development and (2) a scoping review of studies assessing the effects of Zinc supplementation on survival, growth, brain growth, and neurodevelopment in neonates. Very preterm infants and small for gestational age infants are at risk for Zinc deficiency. Zinc deficiency can cause several complications including periorificial lesions, delayed wound healing, hair loss, diarrhea, immune deficiency, growth failure with stunting, and brain atrophy and dysfunction. Zinc is considered essential for oligodendrogenesis, neurogenesis, neuronal differentiation, white matter growth, and multiple biological and physiological roles in neurobiology. Data support the possibility that the critical period of Zinc delivery for brain growth in the mouse starts at 18 days of a 20-21-day pregnancy and extends during lactation and in human may start at 26 weeks of gestation and extend until at least 44 weeks of postmenstrual age. Studies are needed to better elucidate Zinc requirement in extremely low gestational age neonates to minimize morbidity, optimize growth, and brain growth, prevent periventricular leukomalacia and optimize neurodevelopment. IMPACT: Zinc is essential for growth and brain growth and development. In the USA, very preterm small for gestational age infants are at risk for Zinc deficiency. Data support the possibility that the critical period of Zinc delivery for brain growth in the mouse starts at 18 days of a 20-21-day pregnancy and extends during lactation and in human may start at 26 weeks' gestation and extend until at least 44 weeks of postmenstrual age. Several randomized trials of Zinc supplementation in neonates have shown improvement in growth when using high enough dose, for long duration in patients likely to or proven to have a Zinc deficiency. Studies are needed to better elucidate Zinc requirement in extremely low gestational age neonates to minimize morbidity, optimize growth and brain growth, prevent periventricular leukomalacia and optimize neurodevelopment.

Zinc supplementation for the promotion of growth and prevention of infections in infants less than six months of age

BACKGROUND

Zinc is a vital micronutrient for humans and is essential for protein synthesis, cell growth, and differentiation. Severe zinc deficiency can lead to slower physical, cognitive and sexual growth, cause skin disorders, decrease immunity, increase incidence of acute illnesses in infants and children and contribute to childhood stunting. By estimation, 17.3% of the world population is at risk of inadequate zinc intake. Such nutritional impairment increases the risk of diarrhoea and pneumonia by 20%, as well as leads to a global loss of more than 16 million disability-adjusted life years in children less than five years of age. Not only does zinc deficiency affect lives, it adds to the considerable financial burden on depleted resources in countries that are most affected. By preventing or curing this deficiency, we can improve childhood mortality, morbidity and growth.

OBJECTIVES

To assess the effectiveness of zinc supplementation for the promotion of growth, reduction in mortality, and the prevention of infections in infants less than six months of age.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 4), MEDLINE via PubMed (1966 to 18 May 2018), Embase (1980 to 18 May 2018), and CINAHL (1982 to 18 May 2018). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. An updated search from 1 January 2018 to 29 January 2020 was run in the following databases: CENTRAL via CRS Web, MEDLINE via Ovid, and CINAHL via EBSCOhost.

SELECTION CRITERIA

All randomised controlled (individual and cluster randomised) and quasi-randomised trials of zinc supplementation in healthy, term infants, less than six months of age comparing infant mortality, incidence of diarrhoea or respiratory illnesses, growth and/or serum zinc levels were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors screened search results (title and abstracts) and relevant full texts. Studies fulfilling prespecified inclusion criteria were included with any disagreements resolved by consensus. Extraction and analysis were then conducted. We used the GRADE approach to assess the quality of evidence as indicated by certainty in effect estimates.

MAIN RESULTS

Eight studies (with 85,629 infants) were included and five studies were meta-analysed, out of which four studies compared zinc with placebo, and one compared zinc plus riboflavin versus riboflavin. Certain growth outcomes after six months of intervention (Weight for Age Z-scores (WAZ) (standardised mean difference) (SMD) 0.16, 95% CI 0.03 to 0.29; three studies, n = 955; fixed-effect; heterogeneity Chi² P = 0.96); I² = 0%); change in WAZ (SMD 0.16, 95% CI 0.07 to 0.25; one study, n = 386; fixed-effect); (Weight-for-Length Z-score (WLZ) (SMD 0.15, 95% CI 0.02 to 0.28; three studies, n = 955; fixed-effect; heterogeneity: Chi² P = 0.81); I² = 0%); (change in WLZ (SMD 0.17, 95% CI 0.06 to 0.28; one study, n = 386; fixed-effect)) were positively affected by zinc supplementation compared to placebo. A single study reported no difference in the incidence of diarrhoea and lower respiratory tract infection with zinc supplementation. Zinc had no effect on mortality in children younger than 12 months. When zinc plus riboflavin was compared to riboflavin only, significant improvement was observed in the incidence of wasting at 24 months (risk ratio (RR) 0.59, 95% CI 0.37 to 0.96; one study, n = 296; fixed-effect), but significant worsening of incidence of stunting was present at 21 months (RR 1.53, 95% CI 1.09 to 2.16; one study, n = 298; fixed-effect).

AUTHORS' CONCLUSIONS

There was a significant positive impact of zinc supplementation on WAZ and WLZ after six months of intervention in infants compared to placebo. When a combined supplement of zinc and riboflavin was compared to riboflavin, there was a significant reduction in wasting at 24 months, but stunting at 21 months was negatively affected. Although included trials were of good-to-moderate quality, evidence that could be meta-analysed was based on a few studies which affected the overall quality of results. Regardless, there is a need for strong trials conducted in infants younger than six months before a strong recommendation can be made supporting zinc supplementation in this age group.

Multiple micronutrient status and predictors of anemia in young children aged 12-23 months living in New Delhi, India

Anemia has been identified as a severe public health concern among young children in India, however, information on the prevalence of anemia attributed to micronutrient deficiencies is lacking. We aimed to assess multiple micronutrient status (iron, zinc, selenium, vitamin A, vitamin D, folate and vitamin B12) in young Indian children and to investigate the role of these seven micronutrients and other non-nutritional factors on hemoglobin concentrations and anemia. One-hundred and twenty children aged 12 to 23 months were included in a cross-sectional nutritional assessment survey, of which 77 children provided a blood sample. Hemoglobin (Hb), serum ferritin, soluble transferrin receptor (sTfR), total body iron, zinc, selenium, retinol binding protein (RBP), folate, vitamin B12 and 25-hydroxyvitamin D (25(OH)D) were measured, and adjusted for inflammation using C-reactive protein (CRP) and α-1-acid glycoprotein (AGP), where appropriate. Predictors for hemoglobin and anemia were identified in multiple regression models. Most of the children were classified as anemic, of which 86 to 93% was associated with iron deficiency depending on the indicator applied. Deficiencies of folate (37%), and notably vitamin D (74%) were also common; fewer children were classified with deficiencies of vitamin B12 (29%), zinc (25%), and vitamin A (17%) and selenium deficiency was nearly absent. Multiple micronutrient deficiencies were common with over half (57%) deficient in three or more micronutrients, and less than 10% of children were classified with adequate status for all the micronutrients measured. Iron status was found to be the only nutritional factor statistically significantly inversely associated with anemia (P = 0.003) in multivariate analysis after controlling for sex. A coordinated multi-micronutrient program is urgently needed to combat the co-existing micronutrient deficiencies in these young children to improve micronutrient status and reduce the high burden of childhood anemia.

Low-birthweight infants born to short-stature mothers are at additional risk of stunting and poor growth velocity: Evidence from secondary data analyses

Low‐birthweight (LBW) infants are at an increased risk of stunting and poor linear growth. The risk might be additionally higher in these infants when born to short mothers. However, this hypothesis has been less explored. The objective of this secondary data analysis was to determine the risk of linear growth faltering and difference in linear growth velocity in LBW infants born to short mothers (<150 cm) compared to those born to mothers with height ≥150 cm during the first year of life. This analysis uses data from a community‐based randomized controlled trial of 2,052 hospital‐born term infants with birthweight ≤2,500g from urban low–middle socioeconomic neighbourhoods in Delhi, India. Data on maternal height and infant birth length were available from 1,858 (90.5%) of the infants. Infant anthropometry outcomes were measured at birth, 3, 6, 9, and 12 months of age. We found that infants born to short mothers had around twofold higher odds of stunting and lower attained length‐for‐age Z scores compared to infants of mothers with height ≥150 cm, at all ages of assessment. Linear growth velocity was significantly lower in infants of short mothers particularly in the first 6 months of life. We conclude that LBW infants born to short mothers are at a higher risk of stunting and have slower postnatal growth velocity resulting in lower attained length‐for‐age Z scores in infancy. Evidence‐based strategies need to be tested to optimize growth velocity in LBW infants especially those born to short mothers.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around 500,000 child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF).

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library 2016, Issue 5), MEDLINE, Embase, LILACS, CINAHL, mRCT, and reference lists up to 30 September 2016. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that compared oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both review authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. The primary outcomes were diarrhoea duration and severity. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using either a fixed-effect or random-effects model) and assessed heterogeneity.We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Thirty-three trials that included 10,841 children met our inclusion criteria. Most included trials were conducted in Asian countries that were at high risk of zinc deficiency. Acute diarrhoeaThere is currently not enough evidence from well-conducted RCTs to be able to say whether zinc supplementation during acute diarrhoea reduces death or number of children hospitalized (very low certainty evidence).In children older than six months of age, zinc supplementation may shorten the average duration of diarrhoea by around half a day (MD -11.46 hours, 95% CI -19.72 to -3.19; 2581 children, 9 trials, low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, 6 trials, moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (MD -26.39 hours, 95% CI -36.54 to -16.23; 419 children, 5 trials, high certainty evidence).Conversely, in children younger than six months of age, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, 2 trials, moderate certainty evidence), or the number of children who still have diarrhoea on day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, 1 trial, moderate certainty evidence).None of the included trials reported serious adverse events. However, zinc supplementation increased the risk of vomiting in both age groups (children greater than six months of age: RR 1.57, 95% CI 1.32 to 1.86; 2605 children, 6 trials, moderate certainty evidence; children less than six months of age: RR 1.54, 95% CI 1.05 to 2.24; 1334 children, 2 trials, moderate certainty evidence). Persistent diarrhoeaIn children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, 5 trials, moderate certainty evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency.

Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 months

BACKGROUND

Pneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily zinc supplements have been reported to prevent acute lower respiratory tract infection (LRTI) and reduce child mortality. This is an update of a review first published in 2010.

OBJECTIVES

To evaluate the effectiveness of zinc supplementation in the prevention of pneumonia in children aged two to 59 months.

SEARCH METHODS

We searched CENTRAL (Issue 21 October 2016), MEDLINE (1966 to October 2016), Embase (1974 to October 2016), LILACS (1982 to October 2016), CINAHL (1981 to October 2016), Web of Science (1985 to October 2016) and IMSEAR (1980 to October 2016).

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating zinc supplementation for the prevention of pneumonia in children aged from 2 months to 59 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We did not identify any new studies for inclusion in this update. We included six studies that involved 5193 participants.Analysis showed that zinc supplementation reduced the incidence of pneumonia by 13% (fixed-effect risk ratio (RR) 0.87; 95% confidence interval (CI) 0.81 to 0.94, six studies, low-quality evidence) and prevalence of pneumonia by 41% (random-effects RR 0.59; 95% CI 0.35 to 0.99, one study, n = 609, low-quality evidence). On subgroup analysis, we found that zinc reduced the incidence of pneumonia defined by specific clinical criteria by 21% (i.e. confirmation by chest examination or chest radiograph) (fixed-effect RR 0.79; 95% CI 0.0.71 to 0.88, four studies, n = 3261), but had no effect on lower specificity pneumonia case definition (i.e. age-specific fast breathing with or without lower chest indrawing) (fixed-effect RR 0.95; 95% CI 0.86 to 1.06, four studies, n = 1932).

AUTHORS' CONCLUSIONS

Zinc supplementation in children is associated with a reduction in the incidence and prevalence of pneumonia.

Zinc Supplementation in Preterm Neonates and Neurological Development, A Randomized Controlled Trial

OBJECTIVE

To assess the effect of zinc supplementation on neuro-development and growth of preterm neonates.

SETTING

Referral neonatal unit of a teaching hospital.

DESIGN

Open-labeled Randomized controlled trial.

PARTICIPANTS

100 preterm neonates.

INTERVENTION

Participants randomized to receive oral zinc (study group) or not (controls).

MAIN OUTCOME MEASURES

Primary: Neuro-development status at 40 weeks post conceptional age and at 3 month corrected age using Amiel-Tison neurologic assessment. Secondary: anthropometry and serum alkaline phosphatase at 3 months corrected age.

RESULTS

At 40 weeks post-conceptional age, greater number of zinc supplemented infants demonstrated alertness and attention pattern normal for their age (P=0.02). Higher number of controls showed signs of hyper-excitability at 40 week post-conceptional age (P=0.001) and 3 months corrected age (P=0.003). At 3 month corrected age, mean serum alkaline phosphatase level was significantly higher in the study group compared to controls.

CONCLUSION

Zinc supplementation till 3 month corrected age in preterm breastfed infants improves alertness and attention pattern; and decreases signs of hyperexcitability, and proportion with abnormal reflexes.

The potential for zinc stable isotope techniques and modelling to determine optimal zinc supplementation

It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

50 years of neonatology in India, progress and future

India has made impressive gains in its child survival indices during the past half a century with infant mortality rates declining from 159.3 in 1960 to 44 in 2011 and neonatal mortality rate declining from 47 (1990) to 32 (2010). Neonatal health is now an integral part of the countrys flagship program; National Rural Health Mission. Facility based newborn care is not only available in large public and private sectors hospitals, but also in about 300 of Indias district hospitals. Complementing these efforts is home based newborn care being delivered by community health volunteers. The last two decades has also witnessed an increase in newborn research and its incorporation into medical and paramedical education as a major course component. Neonatology now is an independent super-specialty in India. The National Neonatology Forum has had a major role in spearheading reforms in neonatal care in India.

Zinc supplementation reduces morbidity and mortality in very-low-birth-weight preterm neonates: a hospital-based randomized, placebo-controlled trial in an industrialized country

BACKGROUND

Zinc plays a pivotal role in the pathogenesis of many diseases and in body growth. Preterm neonates have high zinc requirements.

OBJECTIVE

The objective of the study was to investigate the efficacy of zinc supplementation in reducing morbidity and mortality in preterm neonates and to promote growth.

DESIGN

This was a prospective, double-blind, randomized controlled study of very-low-birth-weight preterm neonates randomly allocated on the seventh day of life to receive (zinc group) or not receive (control group) oral zinc supplementation. Total prescribed zinc intake ranged from 9.7 to 10.7 mg/d in the zinc group and from 1.3 to 1.4 mg/d in the placebo control group. The main endpoint was the rate of neonates with ≥ 1 of the following morbidities: late-onset sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, periventricular leucomalacia, and retinopathy of prematurity. Secondary outcomes were mortality and body growth.

RESULTS

We enrolled 97 neonates in the zinc group and 96 in the control group. Morbidities were significantly lower in the zinc group (26.8% compared with 41.7%; P = 0.030). The occurrence of necrotizing enterocolitis was significantly higher in the control group (6.3% compared with 0%; P = 0.014). Mortality risk was higher in the placebo control group (RR: 2.37; 95% CI: 1.08, 5.18; P = 0.006). Daily weight gain was similar in the zinc (18.2 ± 5.6 g · kg⁻¹ · d⁻¹) and control (17.0 ± 8.7 g · kg⁻¹ · d⁻¹) groups (P = 0.478).

CONCLUSION

Oral zinc supplementation given at high doses reduces morbidities and mortality in preterm neonates. This trial was registered in the Australian New Zealand Clinical Trial Register as ACTRN12612000823875.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around two million child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2011, Issue 11), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.The quality of evidence has been assessed using the GRADE methods

MAIN RESULTS

Twenty-four trials, enrolling 9128 children, met our inclusion criteria. The majority of the data is from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere. Acute diarrhoea. There is currently not enough evidence from well conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhoea reduces death or hospitalization (very low quality evidence).In children aged greater than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea by around 10 hours (MD -10.44 hours, 95% CI -21.13 to 0.25; 2175 children, six trials, low quality evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, six trials, moderate quality evidence). In children with signs of moderate malnutrition the effect appears greater, reducing the duration of diarrhoea by around 27 hours (MD -26.98 hours, 95% CI -14.62 to -39.34; 336 children, three trials, high quality evidence).Conversely, In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, two trials, low quality evidence), and may even increase the proportion of children whose diarrhoea persists until day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, one trial, moderate quality evidence).No trials reported serious adverse events, but zinc supplementation during acute diarrhoea causes vomiting in both age groups (RR 1.59, 95% 1.27 to 1.99; 5189 children, 10 trials, high quality evidence). Persistent diarrhoea. In children with persistent diarrhoea, zinc supplementation probably shortens the duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, five trials, moderate quality evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Therapeutic zinc and copper supplementation in acute diarrhea does not influence short-term morbidity and growth: double-blind randomized controlled trial

Our objective was to evaluate the effect of zinc and copper supplementation in acute diarrhea on morbidity and growth during 12 weeks of follow-up. In a double-blind randomized controlled clinical trial of 724 children aged 6-59 months, none of the 11 evaluated outcomes showed significant association with zinc or zinc and copper supplementation. Thus, therapeutic zinc supplementation may not always yield short-term -benefits.

Poor zinc status in early infancy among both low and normal birth weight infants and their mothers in Delhi

BACKGROUND

Low birth weight (LBW) infants are at high risk of zinc deficiency, but there is a paucity of data on their zinc status.

OBJECTIVE

To evaluate zinc status of LBW (BW <2,500 g) and normal birth weight (NBW; BW ≥ 2,500 g) infants at birth and in early infancy.

METHODS

A total of 339 infants (LBW, n = 220; NBW, n = 119) were enrolled, and venous blood samples of mother-infant dyad were taken within 48 h of birth. Infants' levels were repeated between 2 and 10 months of age. Serum zinc levels were estimated using an inductively coupled plasma mass spectrometer. Primary outcome was zinc deficiency, defined as serum zinc <65 µg/dl.

RESULTS

Zinc results were available for 182 LBW and 103 NBW infants at birth and for 100 LBW and 66 NBW infants at follow-up with a median postnatal age of 14 and 15.5 weeks, respectively. Median zinc levels were low and comparable at birth as well as at follow-up, with zinc deficiency being present in 51.0% of LBW and 42.4% of NBW infants at birth and in 79.0% of LBW and 66.7% of NBW infants at follow-up. Zinc levels decreased significantly in both groups from birth to follow-up, irrespective of zinc multivitamin supplementation. Zinc levels of infants with BW <2,000 g at follow-up were significantly lower compared to infants with higher BW.

CONCLUSION

Zinc status was poor in many infants at birth irrespective of BW. Zinc status worsened significantly during early infancy, with infants with BW <2,000 g having the lowest zinc levels.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around two million child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2011, Issue 11), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.The quality of evidence has been assessed using the GRADE methods

MAIN RESULTS

Twenty-four trials, enrolling 9128 children, met our inclusion criteria. The majority of the data is from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere.Acute diarrhoeaThere is currently not enough evidence from well conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhoea reduces death or hospitalization (very low quality evidence).In children aged greater than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea by around 10 hours (MD -10.44 hours, 95% CI -21.13 to 0.25; 2091 children, five trials, low quality evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, six trials, moderate quality evidence). In children with signs of moderate malnutrition the effect appears greater, reducing the duration of diarrhoea by around 27 hours (MD -26.98 hours, 95% CI -14.62 to -39.34; 336 children, three trials, high quality evidence).Conversely, In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, two trials, low quality evidence), and may even increase the proportion of children whose diarrhoea persists until day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, one trial, moderate quality evidence).No trials reported serious adverse events, but zinc supplementation during acute diarrhoea causes vomiting in both age groups (RR 1.59, 95% 1.27 to 1.99; 5189 children, 10 trials, high quality evidence).Persistent diarrhoeaIn children with persistent diarrhoea, zinc supplementation probably shortens the duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, five trials, moderate quality evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Short-term zinc supplementation with dispersible tablets or zinc sulfate solution yields similar positive effects on plasma zinc concentration of young children in Burkina Faso: a randomized controlled trial

OBJECTIVE

To assess zinc absorption from dispersible tablets by investigating the effects of short-term zinc supplementation, provided either as zinc (Zn) sulfate dispersible tablets or solution, on changes in plasma Zn concentration in young children.

STUDY DESIGN

We conducted a randomized, partially-masked, placebo-controlled trial in 451 children 6 to 23 months of age in Burkina Faso, randomly assigned to receive a dispersible tablet containing 5 mg Zn, a Zn solution containing 5 mg Zn/5 mL, or a placebo solution, daily for 3 weeks. The main outcome measure was change in plasma zinc concentration after supplementation compared with baseline.

RESULTS

The mean plus or minus SD change in plasma Zn concentration (μg/dL) was significantly greater in both Zn supplemented groups (tablets: 16.9±13.1μg/dL, liquid: 16.6±14.2 μg/dL), compared with the placebo group (0.2±10.9 μg/dL; P<.001, ANOVA). In both Zn supplemented groups, but not in the placebo group, change in plasma Zn concentration was progressively less with increasing age in months (-0.79 μg/dL/mo and -1.15 μg/dL/mo, respectively; P<.001); this effect did not differ in the Zn supplemented groups (P=.18).

CONCLUSIONS

Short-term supplementation results in a large increase in plasma Zn concentration, regardless of whether the additional Zn is provided as a dispersible tablet or solution.

Neonatal zinc supplementation for prevention of mortality and morbidity in breastfed low birth weight infants: systematic review of randomized controlled trials

OBJECTIVES

To evaluate whether zinc supplements prevent mortality and morbidity in breastfed low birth weight infants.

METHODS

All randomized or qausi-randomized trials with individual or cluster allocation and using concurrent controls were included. Study population included LBW infants irrespective of gestational status who were exclusively or predominantly breastfed at the initiation of intervention. Intervention comprised zinc salts given as tablets or syrups orally to provide at least 1 RDA of elemental zinc for at least a period of 14 days, introduced within one month of birth. Electronic databases were searched irrespective of language and publication status.

FINDINGS

Three trials from developing countries met the inclusion criteria. Limited data did not indicate a reduced risk of mortality (1 trial, RR=1.11; 95% CI 0.57 to 2.18 at one year), hospitalization rate (1 trial, odds ratio 1.10; 95% CI 0.87 to 1.39), acute respiratory infection (1 trial), or diarrhea (2 trials). However, the trial reporting on mortality was not adequately powered for evaluating this outcome. There was no evidence of an increase in weight (3 trials) or height (2 trials) at either 6 months or one year of age, or of an increased risk of vomiting following zinc supplementation. Serum zinc levels at the end of intervention were significantly higher in the supplemented group (2 trials).

CONCLUSIONS

In view of no convincing evidence of benefits from the limited data available, currently there is no justification for recommending routine zinc supplementation for breastfed LBW newborns in developing countries.

What zinc supplementation does and does not achieve in diarrhea prevention: a systematic review and meta-analysis

BACKGROUND

Prevention of diarrhea has presented indomitable challenges. A preventive strategy that has received significant interest is zinc supplementation. Existing literature including quantitative meta-analyses and systematic reviews tend to show that zinc supplementation is beneficial however evidence to the contrary is augmenting. We therefore conducted an updated and comprehensive meta-analytical synthesis of the existing literature on the effect of zinc supplementation in prevention of diarrhea.

METHODS

EMBASE®, MEDLINE ® and CINAHL® databases were searched for published reviews and meta-analyses on the use of zinc supplementation for the prevention childhood diarrhea. Additional RCTs published following the meta-analyses were also sought. Effect of zinc supplementation on the following five outcomes was studied: incidence of diarrhea, prevalence of diarrhea, incidence of persistent diarrhea, incidence of dysentery and incidence of mortality. The published RCTs were combined using random-effects meta-analyses, subgroup meta-analyses, meta-regression, cumulative meta-analyses and restricted meta-analyses to quantify and characterize the role of zinc supplementation with the afore stated outcomes.

RESULTS

We found that zinc supplementation has a modest beneficial association (9% reduction) with incidence of diarrhea, a stronger beneficial association (19% reduction) with prevalence of diarrhea and occurrence of multiple diarrheal episodes (28% reduction) but there was significant unexplained heterogeneity across the studies for these associations. Age, continent of study origin, zinc salt and risk of bias contributed significantly to between studies heterogeneity. Zinc supplementation did not show statistically significant benefit in reducing the incidence of persistent diarrhea, dysentery or mortality. In most instances, the 95% prediction intervals for summary relative risk estimates straddled unity.

CONCLUSIONS

Demonstrable benefit of preventive zinc supplementation was observed against two of the five diarrhea-related outcomes but the prediction intervals straddled unity. Thus the evidence for a preventive benefit of zinc against diarrhea is inconclusive. Continued efforts are needed to better understand the sources of heterogeneity. The outcomes of zinc supplementation may be improved by identifying subgroups that need zinc supplementation.

Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 months

BACKGROUND

Pneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily regimens of zinc have been reported to prevent acute lower respiratory tract infection and reduce child mortality.

OBJECTIVES

To evaluate the effectiveness of zinc supplementation in the prevention of pneumonia in children aged two to 59 months.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to January Week 2, 2010), EMBASE (1974 to January 2010) and LILACS (1985 to January 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating supplementation of zinc for the prevention of pneumonia in children aged 2 to 59 months of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included six trials and 7850 participants in the meta-analysis. Analysis showed that zinc supplementation reduced the incidence of pneumonia by 13% (risk ratio (RR) 0.87; 95% confidence interval (CI) 0.81 to 0.94, fixed-effect, six studies) and prevalence of pneumonia by 41% (RR 0.59; 95% CI 0.35 to 0.99, random-effects, one study). On subgroup analysis, we found that zinc reduced the incidence of pneumonia defined by specific clinical criteria by 21% (i.e. confirmation by chest examination or chest radiograph) (RR 0.79; 95% CI 0.0.71 to 0.88, fixed-effect, four studies, n = 4591) but had no effect on lower specificity pneumonia case definition (i.e. age specific fast breathing with or without lower chest indrawing) (RR 0.95; 95% CI 0.86 to 1.06, fixed-effect, four studies, n = 3259).

AUTHORS' CONCLUSIONS

Zinc supplementation in children is associated with a reduction in the incidence and prevalence of pneumonia, the leading cause of death in children.

Oral zinc for treating diarrhoea in children

BACKGROUND

Diarrhoea causes around two million child deaths annually. Zinc supplementation could help reduce the duration and severity of diarrhoea, and is recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH STRATEGY

In November 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 4), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation (>/= 5 mg/day for any duration) with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and methodological quality, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.

MAIN RESULTS

Eighteen trials enrolling 6165 participants met our inclusion criteria. In acute diarrhoea, zinc resulted in a shorter diarrhoea duration (MD -12.27 h, 95% CI -23.02 to -1.52 h; 2741 children, 9 trials), and less diarrhoea at day three (RR 0.69, 95% CI 0.59 to 0.81; 1073 children, 2 trials), day five (RR 0.55, 95% CI 0.32 to 0.95; 346 children, 2 trials), and day seven (RR 0.71, 95% CI 0.52 to 0.98; 4087 children, 7 trials). The four trials (1458 children) that reported on diarrhoea severity used different units and time points, and the effect of zinc was less clear. Subgroup analyses by age (trials with only children aged less than six months) showed no benefit with zinc. Subgroup analyses by nutritional status, geographical region, background zinc deficiency, zinc type, and study setting did not affect the results' significance. Zinc also reduced the duration of persistent diarrhoea (MD -15.84 h, 95% CI -25.43 to -6.24 h; 529 children, 5 trials). Few trials reported on severity, and results were inconsistent. No trial reported serious adverse events, but vomiting was more common in zinc-treated children with acute diarrhoea (RR 1.71, 95% 1.27 to 2.30; 4727 children, 8 trials).

AUTHORS' CONCLUSIONS

In areas where diarrhoea is an important cause of child mortality, research evidence shows zinc is clearly of benefit in children aged six months or more.