Effect of preventive zinc supplementation on linear growth in children under 5 years of age in developing countries: a meta-analysis of studies for input to the lives saved tool

Zinc and other micronutrients supplementation through the use of sprinkles: impact on the occurrence of diarrhea and respiratory infections in institutionalized children

OBJECTIVE

To evaluate the incidence of diarrheal disease (DD) and acute respiratory infection (ARI) in children undergoing supplementation of zinc and other micronutrients through the use of sprinkles, as well as their acceptance by these patients.

METHOD

This was a randomized double-blinded clinical trial of 143 healthy institutionalized children, aged 6 to 48 months. They were randomized into two groups and received daily zinc and micronutrients - test group (sprinkles), or micronutrients without zinc - control group. Children were supplemented for 90 days and followed regarding the outcomes of DD and ARI.

RESULTS

Of the randomized children, 52.45% belonged to the test and 47.55% to the control group. The incidence of DD in the test group was 14.7% and was 19.1% in the control group. The test group showed a lower risk of developing DD when compared to controls, but this finding was not statistically significant (RR=0.77 [0.37 to 1.6], p=0.5088). ARI had high incidence in both groups, 60% in the test group and 48.5% in the control group, with an increased risk of developing the disease in the test group, but with no statistical significance (RR=1.24 [0.91 to 1.68], p=0.1825). Regarding acceptance, the mean percentage of consumption, in days, of the entire content of the sachets containing sprinkles was 95.72% (SD=4.9) and 96.4% (SD=6.2) for the test and control groups, respectively.

CONCLUSIONS

Zinc supplementation through the use of sprinkles did not reduce the incidence of DD or ARI among the evaluated children. The sprinkles were well accepted by all study participants.

Micronutrient supply and health outcomes in children

PURPOSE OF REVIEW

Multiple micronutrient deficiencies are still common worldwide and often occur at an early age, negatively affecting both physical and cognitive development. Even though specific effects of a variety of different micronutrients have been studied extensively, it is understood that a combination of multiple micronutrients may be more beneficial in most instances, as deficiencies usually do not occur in isolation. The aim of this review was to summarize the most recent evidence of the effects of micronutrient interventions on growth, mental, and physical performance as well as morbidity in children.

RECENT FINDINGS

For growth, cognitive or motor function, and morbidity, it appears that providing sufficient amounts of micronutrients especially to the most vulnerable and deficient groups of children can make a difference, but also that the intervention has to be planned carefully. However, findings are still variable, more particularly with reference to morbidity. Two reports of increased diagnoses of infection with micronutrient supplementation are also of concern.

SUMMARY

There are still difficulties in coming to a universal conclusion about benefit in all populations, because reports vary in study design, population, and so on. Although micronutrients have a role in depleted groups, it is also important to not only consider the group of children targeted, but also the regime of administration.

Practical approach to nutrition and dietary intervention in pediatric food allergy

Although the need for nutritional and dietary intervention is a common thread in food allergy management, the type of food allergic disorder and the identified food allergen will influence the approach to dietary intervention. A comprehensive nutrition assessment with appropriate intervention is warranted in all children with food allergies to meet nutrient needs and optimize growth. However, dietary elimination in food allergy may also have undesirable consequences. Frequently, an elimination diet is absolutely necessary to prevent potentially life-threatening food allergic reactions. Allergen elimination can also ease chronic symptoms, such as atopic dermatitis, when a food is proven to trigger symptoms. However, removing a food with proven sensitivity to treat chronic symptoms may increase the risk of an acute reaction upon reintroduction or accidental ingestion after long-term avoidance, so it is not without risk. Additionally, it is not recommended to avoid foods in an attempt to control chronic symptoms such as AD and EoE when allergy to the specific food has not been demonstrated. Ultimately, allergen elimination goals are to prevent acute and chronic food allergic reactions in the least restrictive, but also the safest environment to supply a balanced diet that promotes health and growth and development in children.

Zinc supplementation does not alter sensitive biomarkers of copper status in healthy boys

The tolerable upper intake levels (UL) for zinc for children were based on limited data and there is concern that the UL may be set too low. The first effect of excessive zinc intake is a reduction in copper status. The primary objective of this study was to examine the effect of zinc supplementation on copper status in children. Healthy, 6- to 8-y-old boys from Ontario, Canada were assigned to take a placebo (n = 10) or 5 mg (n = 10), 10 mg (n = 9), or 15 mg (n = 8) of zinc supplement daily for 4 mo in a double-blinded, placebo-controlled, randomized trial. Biochemical measures were evaluated at baseline and after 2 and 4 mo of supplementation. Food records were completed near the baseline and 4-mo visits. Age and anthropometric measurements did not differ (P > 0.05) between treatment groups at baseline. Mean zinc intakes from food alone (10.9-14.8 mg zinc/d) approached or exceeded the UL of 12 mg/d. Compared with the placebo group, the zinc groups had a greater change in the urine zinc:creatinine ratio at 4 mo (P = 0.02). Traditional (plasma copper and ceruloplasmin activity) and more sensitive biomarkers of copper status, including erythrocyte SOD1 activity and the erythrocyte CCS:SOD1 protein ratio, were unchanged in zinc-supplemented boys, demonstrating that copper status was not depressed. Serum lipid measures and hemoglobin concentrations were also unaffected and gastrointestinal symptoms were not reported. These data provide evidence in support of the need for reexamining the current UL for zinc for children.

Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

BACKGROUND

Non-fatal health outcomes from diseases and injuries are a crucial consideration in the promotion and monitoring of individual and population health. The Global Burden of Disease (GBD) studies done in 1990 and 2000 have been the only studies to quantify non-fatal health outcomes across an exhaustive set of disorders at the global and regional level. Neither effort quantified uncertainty in prevalence or years lived with disability (YLDs).

METHODS

Of the 291 diseases and injuries in the GBD cause list, 289 cause disability. For 1160 sequelae of the 289 diseases and injuries, we undertook a systematic analysis of prevalence, incidence, remission, duration, and excess mortality. Sources included published studies, case notification, population-based cancer registries, other disease registries, antenatal clinic serosurveillance, hospital discharge data, ambulatory care data, household surveys, other surveys, and cohort studies. For most sequelae, we used a Bayesian meta-regression method, DisMod-MR, designed to address key limitations in descriptive epidemiological data, including missing data, inconsistency, and large methodological variation between data sources. For some disorders, we used natural history models, geospatial models, back-calculation models (models calculating incidence from population mortality rates and case fatality), or registration completeness models (models adjusting for incomplete registration with health-system access and other covariates). Disability weights for 220 unique health states were used to capture the severity of health loss. YLDs by cause at age, sex, country, and year levels were adjusted for comorbidity with simulation methods. We included uncertainty estimates at all stages of the analysis.

FINDINGS

Global prevalence for all ages combined in 2010 across the 1160 sequelae ranged from fewer than one case per 1 million people to 350,000 cases per 1 million people. Prevalence and severity of health loss were weakly correlated (correlation coefficient -0·37). In 2010, there were 777 million YLDs from all causes, up from 583 million in 1990. The main contributors to global YLDs were mental and behavioural disorders, musculoskeletal disorders, and diabetes or endocrine diseases. The leading specific causes of YLDs were much the same in 2010 as they were in 1990: low back pain, major depressive disorder, iron-deficiency anaemia, neck pain, chronic obstructive pulmonary disease, anxiety disorders, migraine, diabetes, and falls. Age-specific prevalence of YLDs increased with age in all regions and has decreased slightly from 1990 to 2010. Regional patterns of the leading causes of YLDs were more similar compared with years of life lost due to premature mortality. Neglected tropical diseases, HIV/AIDS, tuberculosis, malaria, and anaemia were important causes of YLDs in sub-Saharan Africa.

INTERPRETATION

Rates of YLDs per 100,000 people have remained largely constant over time but rise steadily with age. Population growth and ageing have increased YLD numbers and crude rates over the past two decades. Prevalences of the most common causes of YLDs, such as mental and behavioural disorders and musculoskeletal disorders, have not decreased. Health systems will need to address the needs of the rising numbers of individuals with a range of disorders that largely cause disability but not mortality. Quantification of the burden of non-fatal health outcomes will be crucial to understand how well health systems are responding to these challenges. Effective and affordable strategies to deal with this rising burden are an urgent priority for health systems in most parts of the world.

FUNDING

Bill & Melinda Gates Foundation.

Nutritional zinc status in weaning infants: association with iron deficiency, age, and growth profile

In the present study, we evaluated the correlation between iron deficiency (ID) and zinc deficiency (ZD) and explored the demographic, anthropometric, and feeding-related factors associated with hypozincemia and hair zinc content in weaning infants. Infants aged 6-24 months were recruited, their feeding history was recorded, and their heights and weights were measured. Hemoglobin content, serum iron/total iron-binding capacity, and ferritin and zinc concentrations of serum and hair (using inductively coupled plasma-mass spectroscopy) were assessed. Among 101 infants, 64 (63.4 %) infants exhibited ID. The median serum zinc concentration in iron-deficient infants was lower than that in non-iron-deficient infants, respectively, 73.5 μg/dL (interquartile range [IQR], 65.0-83.8) vs. 87.0 μg/dL (IQR, 77.5-97.0; p = 0.001). The frequency of hypozincemia was also significantly higher in the iron-deficient group than in the non-iron-deficient group (21 out of 64 [32.8 %] vs. 4 out of 37 [10.8 %], respectively; p = 0.014). In multiple regression analysis, the risk of hypozincemia was significantly increased in infants with ID (p = 0.026), mildly underweight infants (weight-for-age Z score < -1; p = 0.034), and infants with mild wasting (weight-for-height Z score < -1; p = 0.028). Hair zinc concentrations (n = 81) were not significantly associated with ID status (p > 0.1); however, there was an inverse relationship between hair zinc concentrations and age of infants (r = -0.250; p = 0.024). In weaning infants, ID is a risk factor for hypozincemia. Hair zinc concentrations appeared to decrease as the age of infants increased during late infancy. Further large-scale studies are needed to validate the relationship between hypozincemia and mild degrees of weight gain impairment in this age group.

Practical dietary management of protein energy malnutrition in young children with cow's milk protein allergy

Cow's milk protein allergy (CMPA) affects between 1.9 and 4.9% of infants and young children. This food allergy requires the complete elimination of cow's milk and its derivatives, impacting on nutritional status. The risk of having protein energy malnutrition (PEM) in children with CMPA has been well documented. In 2007, the World Health Organisation published guidelines on the dietary management of PEM, which has impacted on the recommendations and composition on specialist feeds for many chronic diseases, but not on CMPA. The main change in management of the child with PEM is the protein energy ratio and energy requirements. The ideal protein energy ratio lies between 8.9 and 11.5%, which would ensure a deposition of about 70% lean and 30% fat mass. In addition, for optimal catch-up growth between 5 and 10 g/kg/day, energy requirements should be between 105 and 126 kcal/kg/day. Although most current hypoallergenic formulas fall well within the recommendation for protein, there is a problem in achieving energy requirements. As a result, modular additions are often made, disturbing the protein energy ratio or feeds are concentrated, which impacts on osmolality. We therefore aimed to review current guidelines on PEM and how these can be applied in the management of the malnourished child with CMPA.

The role of biomarkers in evaluating human health concerns from fungal contaminants in food

Mycotoxins are toxic secondary metabolites that globally contaminate an estimated 25 % of cereal crops and thus exposure is frequent in many populations. Aflatoxins, fumonisins and deoxynivalenol are amongst those mycotoxins of particular concern from a human health perspective. A number of risks to health are suggested including cancer, growth faltering, immune suppression and neural tube defects; though only the demonstrated role for aflatoxin in the aetiology of liver cancer is widely recognised. The heterogeneous distribution of mycotoxins in food restricts the usefulness of food sampling and intake estimates; instead biomarkers provide better tools for informing epidemiological investigations. Validated exposure biomarkers for aflatoxin (urinary aflatoxin M(1), aflatoxin-N7-guaunine, serum aflatoxin-albumin) were established almost 20 years ago and were critical in confirming aflatoxins as potent liver carcinogens. Validation has included demonstration of assay robustness, intake v. biomarker level, and stability of stored samples. More recently, aflatoxin exposure biomarkers are revealing concerns of growth faltering and immune suppression; importantly, they are being used to assess the effectiveness of intervention strategies. For fumonisins and deoxynivalenol these steps of development and validation have significantly advanced in recent years. Such biomarkers should better inform epidemiological studies and thus improve our understanding of their potential risk to human health.

Promoting healthy growth: what are the priorities for research and action?

Healthy growth from conception through the first 2 y of life is the foundation for adequate organ formation and function, a strong immune system, physical health, and neurological and cognitive development. Recent studies identified several low-cost interventions to address undernutrition during this age period and noted the lower returns on investment of intervening after this critical period. Although these interventions should be implemented widely, it is recognized that existing nutrition solutions, even if universally applied, would only avert a minority fraction of the estimated death and disability due to undernutrition. This paper reviews some of the knowledge and learning needed to close this "impact gap." Five areas are prioritized for future research: 1) study healthy growth from a lifecycle perspective, because maternal, fetal, and newborn outcomes are connected; 2) understand why growth faltering begins so early in breast-fed infants in the developing world; 3) apply new tools and technologies to study long-recognized problems such as the interaction between nutrition and infection; 4) explore new hypotheses for understanding nutrient assimilation and use to discover and develop intervention leads; and 5) understand the role of the environment in healthy growth and the potential synergistic benefits of multi-sectoral interventions. Policymakers are urged to invest in nutrition-specific and -sensitive interventions to promote healthy growth from conception through the first 2 y of life because of their immediate and long-term health and development benefits.