Predictors of plasma zinc concentrations in children with acute diarrhea

Distribution and Determinants of Serum Zinc, Copper, and Selenium Levels among Children under Five Years from Popokabaka, Democratic Republic of Congo: A Cross-Sectional Study

Information about essential trace elements among children in many African countries, including the Democratic Republic of Congo (DRC), is limited. We aimed to measure the distribution and determinants of serum zinc (Zn), copper (Cu), and selenium (Se) concentrations in a representative sample of children under five years old. We conducted a community-based cross-sectional study in Popokabaka, DRC. Blood samples were drawn from 412 children. The serum concentrations of minerals were measured using inductively coupled plasma−mass spectrometry. The median concentrations (P25−P75) of Zn, Cu, and Se were 61.9 µg/dL (52.8−70.2), 145.5 (120.0−167.0) µg/dL and 5.3 (4.3−6.3) µg/dL. The CRP-adjusted prevalence of serum Se deficiency was 84.1% (95% confidence interval [CI] 81.4−87.0) and of Zn deficiency was 64.6% (95% CI 59.8−69.1%). Only a few children were Cu deficient [1.5% (0.6−3.2)]. Evidence of inflammation (C-reactive protein, >5 mg/L) was associated with a lower Se concentration and higher Cu concentration. Furthermore, serum Se concentration was positively associated with linear growth. The average Cu/Zn molar ratio (2:1) was twice that recommended. Children in western Popokabaka had higher Zn and Se levels than their eastern neighbors. Zinc and selenium deficiencies are common among children in Popokabaka and require attention and prioritization.

Serum zinc status is a matter of concern among children and non-pregnant women in a nationwide survey of Nepal

Nationally representative population data on zinc status in Nepal is lacking at present. This study analyzed data from the recent Nepal National Micronutrient status survey 2016 to determine the prevalence of zinc deficiency and associated risk factors among children aged 6-59 months (n = 1462) and non-pregnant women aged 15-49 years (n = 1923). Venous blood was collected from the participants to measure micronutrients such as zinc, markers of anemia, RBP (vitamin A), and markers of inflammation. Stool samples were collected to assess soil-transmitted helminths and Helicobacter pylori infection. Socio-demographic, household, and other relevant factors were collected by a structured questionnaire. Serum zinc concentration was measured by Microwave Plasma Atomic Emission Spectrometry, and zinc deficiency was defined according to the International Zinc Nutrition Consultative Group's guidelines. Logistic regression was used to examine the predictors of zinc deficiency among the participants. The overall zinc deficiency in children was 22.9%, while it was higher in non-pregnant women (24.7%). The prevalence of anemia among zinc-deficient children was higher (21.3%) than the zinc non-deficit children (18.7%). The prevalence of anemia was 18% among zinc-deficient non-pregnant women compared to 22% non-deficit non-pregnant women. Predictors associated with zinc deficiency among the study children were living in rural areas (AOR = 2.25, 95% CI, [1.13, 4.49]), the occurrence of diarrhea during the two weeks preceding the survey (AOR = 1.57, 95% CI, [1.07, 2.30]), lowest household wealth quintile (AOR = 0.48, 95% CI, [0.25, 0.92]) and lower vitamin A status (AOR = 0.49, 95% CI, [0.28, 0.85]. The predictors associated with zinc deficiency among non-pregnant women were: being underweight (AOR = 1.55, 95% CI, [1.12, 2.15]), fever occurrence during two weeks preceding the survey (AOR = 1.43, 95% CI, [1.04, 1.98]), H. pylori in the stool (AOR = 1.33, 95% CI, [1.04, 1.71]), lowest household wealth quintile (AOR = 0.62, 95% CI,[0.40, 0.94]) and being at risk of folate deficiency (AOR = 0.58, 95% CI,[0.36, 0.94]). We conclude that community-level intervention programs focused on rural children and women to prevent diarrhea, improve nutrition counseling, and provide economic opportunities in rural communities may help to lower zinc deficiency and other micronutrient deficiencies in the Nepalese population. We believe that intervention programs to address zinc deficiency should not be isolated. Instead, integrated approaches are beneficial to improve overall micronutrient status, such as encouraging dietary diversity, providing livelihood opportunities to the unemployed, micronutrient supplementation to vulnerable populations, and consumption of zinc-rich animal-based foods.

A comparative study of the prevalence of zinc deficiency among children with acute diarrhoea in SouthWestern Nigeria

Background

Zinc deficiency has been associated with increased incidence, severity and duration of childhood diarrhoea.

Objective

The objective of the study was to determine the prevalence of zinc deficiency among under-five children with acute diarrhoea.

Methods

The study was a comparative cross-sectional study in which serum zinc levels were determined using atomic absorption spectrometry in under-five children with acute diarrhoea and in apparently healthy contols. Two hundred and fifty children with acute diarrhoea and 250 controls were studied at the Wesley Guild Hospital, Ilesa, Nigeria.

Results

The diarrhoea patients had a mean ± SD serum zinc level of 78.8 ± 35.6 µg/dl, while the controls had a mean of 107.3 ± 46.8 µg/dl. The mean serum zinc level was significantly lower in the patients than the controls (t = -7.66; p < 0.001). Furthermore, the prevalence of zinc deficiency was significantly higher among the patients (30.4% versus 12.4% in the controls; OR = 3.09; 95% CI = 1.94 – 4.90; χ2 = 24.08; p < 0.001). Low social class was associated with a significantly higher prevalence of zinc deficiency among the patients (p = 0.013).

Conclusion

Zinc deficiency is significantly associated with diarrhoea among under-five children in the study community. Hence, routine zinc supplementation should be encouraged for the treatment of diarrhoea, and availability should be ensured.

Serum Zinc Levels as a Predictor of Severity of Acute Diarrhea

OBJECTIVE

To determine relationship between serum zinc levels and severity of diarrhea as determined by hydration status, duration of diarrhea and requirement for hospitalization. Also, to compare serum zinc levels in relation to rotavirus status.

METHODS

A prospective observational study which included 254 children aged 6 mo to 5 y with diarrhea was conducted.

RESULTS

Serum zinc levels could be estimated in 198 children. Median (IQR) serum zinc levels of study population were 73.5 (59.11-92.86)μg/dl. Median (IQR) of serum zinc levels in children with dehydration and without dehydration were 69.64 (54.57-81.62) and 82.86 (64.1-103.48) μg/dl respectively (p < 0.001). Median (IQR) of serum zinc levels in hospitalised and non-hospitalished children were 63.28 (51.81-85.37) and 74.86 (61.75-95.78) μg/dl, respectively (p 0.013). Median (IQR) of total duration of diarrhea was 4.8 (3.5-6.0) d and it did not correlate with serum zinc levels. Median (IQR) of serum zinc levels in children, with rotavirus diarrhea was 66.8 (49.7-82.48) and non-rotavirus diarrhea was 80.0 (62.42-100.12) μg/dl (p < 0.001).

CONCLUSIONS

Children with dehydration and those with rotavirus diarrhea tend to have significantly lower serum zinc levels. Hospitalized children also have lower serum zinc levels than non-hospitalized children. Duration of diarrhea does not relate with serum zinc levels.

Identification of a Hemolysis Threshold That Increases Plasma and Serum Zinc Concentration

Background: Plasma or serum zinc concentration (PZC or SZC) is the primary measure of zinc status, but accurate sampling requires controlling for hemolysis to prevent leakage of zinc from erythrocytes. It is not established how much hemolysis can occur without changing PZC/SZC concentrations.Objective: This study determines a guideline for the level of hemolysis that can significantly elevate PZC/SZC.Methods: The effect of hemolysis on PZC/SZC was estimated by using standard hematologic variables and mineral content. The calculated hemolysis threshold was then compared with results from an in vitro study and a population survey. Hemolysis was assessed by hemoglobin and iron concentrations, direct spectrophotometry, and visual assessment of the plasma or serum. Zinc and iron concentrations were determined by inductively coupled plasma spectrometry.Results: A 5% increase in PZC/SZC was calculated to result from the lysis of 1.15% of the erythrocytes in whole blood, corresponding to ∼1 g hemoglobin/L added into the plasma or serum. Similarly, the addition of simulated hemolysate to control plasma in vitro caused a 5% increase in PZC when hemoglobin concentrations reached 1.18 ± 0.10 g/L. In addition, serum samples from a population nutritional survey were scored for hemolysis and analyzed for changes in SZC; samples with hemolysis in the range of 1-2.5 g hemoglobin/L showed an estimated increase in SZC of 6% compared with nonhemolyzed samples. Each approach indicated that a 5% increase in PZC/SZC occurs at ∼1 g hemoglobin/L in plasma or serum. This concentration of hemoglobin can be readily identified directly by chemical hemoglobin assays or indirectly by direct spectrophotometry or matching to a color scale.Conclusions: A threshold of 1 g hemoglobin/L is recommended for PZC/SZC measurements to avoid increases in zinc caused by hemolysis. The use of this threshold may improve zinc assessment for monitoring zinc status and nutritional interventions.

Health effects from exposure to atmospheric mineral dust near Las Vegas, NV, USA

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Atmospheric geogenic dust comprised of a mineral-metal mixture is a source of exposure in Clark County, Nevada.

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Lung exposures over a period of one month to NDRA atmospheric geogenic dust suppressed immune function in a mouse model.

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Similar geological desert surfaces emit dust in southern Nevada and elsewhere in the world.

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This study is representative of a desert environment; dust composition may vary by source.

Desert areas are usually characterized by a continuous deposition of fine airborne particles. Over time, this process results in the accumulation of silt and clay on desert surfaces. We evaluated health effects associated with regional atmospheric dust, or geogenic dust, deposited on surfaces in the Nellis Dunes Recreation Area (NDRA) in Clark County, Nevada, a popular off-road vehicle (ORV) recreational site frequented daily by riders, families, and day campers. Because of atmospheric mixing and the mostly regional origin of the accumulated particles, the re-suspended airborne dust is composed of a complex mixture of minerals and metals including aluminum, vanadium, chromium, manganese, iron, cobalt, copper, zinc, arsenic, strontium, cesium, lead, uranium, and others. Geogenic dust with a median diameter of 4.1 μm was administered via oropharyngeal aspiration to female B6C3F1 mice at doses of 0.01 to 100 mg dust/kg body weight, four times, a week apart, for 28-days. Immuno- and neurotoxicological outcomes 24 h following the last exposure were evaluated. Antigen-specific IgM responses were dose-responsively suppressed at 0.1, 1.0, 10 and 100 mg/kg/day. Splenic and thymic lymphocytic subpopulations and natural killer cell activity also were significantly reduced. Antibodies against MBP, NF-68, and GFAP were not affected, while brain CD3⁺ T cells were decreased in number. A lowest observed adverse effect level (LOAEL) of 0.1 mg/kg/day and a no observed adverse effect level (NOAEL) of 0.01 mg/kg/day were derived based on the antigen-specific IgM responses.

The Efficacy of Zinc Administration in the Treatment of Primary Dysmenorrhea

OBJECTIVES

Dysmenorrhea is a common complaint in women. Primary dysmenorrhea is defined as painful menstruation in the absence of pelvic disease and is caused by uterine contractions caused by prostaglandins released from the endometrium. Conventional treatments include nonsteroidal anti-inflammatory drugs and oral contraceptives. We sought to evaluate the efficacy of zinc supplementation in the treatment of primary dysmenorrhea. .

METHODS

Two-hundred participants with primary dysmenorrhea were randomized into one of two groups. The intervention group received zinc and mefenamic acid, and the control group received mefenamic acid and a placebo drug. After three months of treatment, changes in the incidence of dysmenorrhea and the degree of pain were measured in both groups. .

RESULTS

The mean pain score before administration of zinc and mefenamic acid in the intervention group was 5.3±1.8 and after treatment was 1.2±1.9 (p < 0.001). In the control group, the mean pain score before administration of mefenamic acid and placebo was 5.8±2.1 and after treatment was 2.9±2.6 (p < 0.001). The difference in pain levels before and after treatment in the intervention group was 4.1±2.8, and in the control group was 2.9±1.7 (p > 0.050). We also found that 64% of case group and 33% of the control group did not experience dysmenorrhea after treatment (p < 0.001). .

CONCLUSIONS

The use of a zinc supplement in combination with mefenamic acid was superior in reducing primary dysmenorrhea compared to mefenamic acid alone.

Prevalence of Iron Deficiency and Anemia among Young Children with Acute Diarrhea in Bhaktapur, Nepal

Iron deficiency anemia is still common in children under five years of age and may impair their growth and cognitive development. Diarrhea is the second most common reason for seeking medical care for young children in Nepal. However, neither screening programs nor effective preventive measures for anemia and iron deficiencies are in place among children with diarrhea in many developing countries. The aims of this study were to determine the prevalence of anemia and iron deficiency and explore their associations with clinical, socioeconomic, and anthropometric parameters in Nepalese children. This was a cross-sectional study based on 1232 children, six to 35 months old, with acute diarrhea participating in a zinc supplementation trial. The mean (SD) hemoglobin was 11.2 g/dL (1.2). Anemia was found in 493 children (40%); this estimate increased to 641 (52%) when we adjusted for the altitude of the study area (hemoglobin <11.3 g/dL). One in every three children had depleted iron stores and 198 (16%) of the children had both depleted iron stores and anemia, indicating iron deficiency anemia. The prevalence of anemia among children presenting with acute diarrhea was high but the degree of severity was mainly mild or moderate. Iron deficiency explained less than half of the total anemia, indicating other nutritional deficiencies inducing anemia might be common in this population.

Zinc supplementation fails to increase the immunogenicity of oral poliovirus vaccine: a randomized controlled trial

BACKGROUND

Polio eradication remains a challenge in Pakistan and the causes for the failure to eradicate poliomyelitis are complex. Undernutrition and micronutrient deficiencies, especially zinc deficiency, are major public health problems in Pakistan and could potentially affect the response to enteric vaccines, including oral poliovirus vaccine (OPV).

OBJECTIVE

To assess the impact of zinc supplementation among infants on immune response to oral poliovirus vaccine (OPV).

METHODS

A double-blind, randomized placebo-controlled trial was conducted in newborns (aged 0-14 days). Subjects were assigned to either receive 10mg of zinc or placebo supplementation daily for 18 weeks. Both groups received OPV doses at birth, at 6 weeks, 10 weeks and 14 weeks. Data was collected on prior immunization status, diarrheal episodes, breastfeeding practices and anthropometric measurements at recruitment and at 6 and 18 weeks. Blood samples were similarly collected to determine the antibody response to OPV and for micronutrient analysis. Logistic regression was used to determine the relationship between seroconversion and zinc status.

RESULTS

Overall, 404 subjects were recruited. At recruitment, seropositivity was already high for poliovirus (PV) serotype 1 (zinc: 91.1%; control: 90.5%) and PV2 (90.0%; 92.7%), with lower estimates for PV3 (70.0%; 64.8%). By week 18, the proportion of subjects with measured zinc levels in the normal range (i.e. ≥60 μg/dL) was significantly greater in the intervention group compared to the control group (71.9%; 27.4%; p<0.001). No significant difference in seroconversion was demonstrated between the groups for PV1, PV2, or PV3.

CONCLUSIONS

There was no effect of zinc supplementation on OPV immunogenicity. These conclusions were confirmed when restricting the analysis to those with measured higher zinc levels.

Acute and subacute response of iron, zinc, copper and selenium in pigs experimentally infected with Actinobacillus pleuropneumoniae

Experimental bacterial lung infection affects trace elements in blood and liver tissue.

Association between serum zinc concentration and the Plasmodium falciparum antibody titer among rural villagers of Attapeu Province, Lao People's Democratic Republic

Experimental studies have indicated that low serum zinc levels affect immune responses. However, few studies have evaluated the impact of serum zinc levels on antibody responses in the field in developing countries. We investigated an association between the anti-Plasmodium falciparum (Pf) antibody (immunoglobulin G) titer and serum zinc concentration among villagers in rural areas of the Lao People's Democratic Republic. Blood samples were collected to detect Pf infection. An enzyme-linked immunosorbent assay (ELISA) was used to measure the anti-PfIgG antibody titer. Each serum sample was assayed to measure the concentration of zinc. Pearson's correlation coefficient was applied to the association between zinc concentration and anti-PfIgG antibody titers. Multiple linear regression analysis was used to assess the association between zinc concentration and anti-PfIgG antibody titers, controlling for age and albumin level. Of 71 blood samples, 40 were Pf positive and 31 were Pf negative. The median serum zinc concentrations were 56.0 μg/dl in the Pf-positive group and 62.5 μg/dl in the Pf-negative group. The median anti-Pf titers were 833.4 in the positive group and 1237.2 in the negative group. Unexpectedly, there was a negative correlation between serum zinc and anti-Pf IgG antibody titers; the correlation coefficient were -0.453 and (p=0.003) in the positive group and -0.461 (p=0.009) in the negative group. The results of this study indicated sustained antibody responses among the villagers, who had likely been exposed to malaria periodically throughout their lives. Further studies are necessary to determine the conditions in which zinc could be effective against malaria.

Risk factors for extended duration of acute diarrhea in young children

OBJECTIVE AND BACKGROUND

We sought to identify predictors of extended duration of diarrhea in young children, which contributes substantially to the nearly 1 1/2 million annual diarrheal deaths globally.

METHODS

We followed 6-35 month old Nepalese children enrolled in the placebo-arm of a randomized controlled trial with 391 episodes of acute diarrhea from the day they were diagnosed until cessation of the episode. Using multiple logistic regression analysis, we identified independent risk factors for having diarrhea for more than 7 days after diagnosis.

RESULTS

Infants had a 17 (95% CI 3.5, 83)-fold and toddlers (12 to 23 month olds) a 9.9 (95% CI 2.1, 47)-fold higher odds of having such illness duration compared to the older children. Not being breastfed was associated with a 9.3 (95% CI 2.4, 35.7)-fold increase in the odds for this outcome. The odds also increased with increasing stool frequency. Furthermore, having diarrhea in the monsoon season also increased the risk of prolonged illness.

CONCLUSION

We found that high stool frequency, not being breastfed, young age and acquiring diarrhea in the rainy season were risk factors for prolonged diarrhea. In populations such as ours, breastfeeding may be the most important modifiable risk factor for extended duration of diarrhea.

A randomized controlled trial of zinc as adjuvant therapy for severe pneumonia in young children

BACKGROUND AND OBJECTIVE

Diarrhea and pneumonia are the leading causes of illness and death in children <5 years of age. Zinc supplementation is effective for treatment of acute diarrhea and can prevent pneumonia. In this trial, we measured the efficacy of zinc when given to children hospitalized and treated with antibiotics for severe pneumonia.

METHODS

We enrolled 610 children aged 2 to 35 months who presented with severe pneumonia defined by the World Health Organization as cough and/or difficult breathing combined with lower chest indrawing. All children received standard antibiotic treatment and were randomized to receive zinc (10 mg in 2- to 11-month-olds and 20 mg in older children) or placebo daily for up to 14 days. The primary outcome was time to cessation of severe pneumonia.

RESULTS

Zinc recipients recovered marginally faster, but this difference was not statistically significant (hazard ratio = 1.10, 95% CI 0.94-1.30). Similarly, the risk of treatment failure was slightly but not significantly lower in those who received zinc (risk ratio = 0.88 95% CI 0.71-1.10).

CONCLUSIONS

Adjunct treatment with zinc reduced the time to cessation of severe pneumonia and the risk of treatment failure only marginally, if at all, in hospitalized children.

A homogeneous fluorescent sensor for human serum albumin

Human serum albumin is the most abundant protein in the body and is an important biomarker used for disease-related diagnosis. Although the traditional enzyme-linked immunosorbent assay (ELISA) approach can precisely measure the concentration of human serum albumin, the multi-step procedure and time-consuming preparations of ELISA limit its diagnostic applications, preventing accurate point-of-care testing, for example. Herein, we report the recent development of an antibody-based albumin sensor that allows for a homogeneous measurement of albumin concentrations in saliva, urine and serum, in which this type of sensor is validated for the first time. The assay only requires simple mixing, and relies on time-resolved (TR) fluorescence resonance energy transfer (FRET) to produce robust, sensitive signals. The whole process, from sample preparation to final read-out, is expected to take less than 1h and requires only a standard plate-reader, thus making the sensor a convenient and cost-effective tool for albumin analysis.

Cobalamin status modifies the effect of zinc supplementation on the incidence of prolonged diarrhea in 6- to 30-month-old north Indian children

The observed effect of zinc supplementation on diarrheal morbidity varies between trials and there is a need to identify subgroups most likely to benefit from improved zinc nutriture. In a randomized, double-blind trial in 2296 children in New Delhi, India, we assessed whether baseline cobalamin or folate status modified the effect of zinc supplementation on the incidence of prolonged (≥ 7 d duration) and acute diarrhea. Children aged 6-30 mo received zinc or placebo daily for 4 mo. We measured plasma concentrations of folate, cobalamin, total homocysteine (tHcy), and methylmalonic acid (MMA) at enrollment and assessed the efficacy of zinc supplementation in subgroups based on these variables. The efficacy of zinc on reducing the risk of prolonged diarrhea was higher in those with plasma cobalamin concentrations below the 25th percentile and in those with tHcy and MMA concentrations above the 75th percentile. The OR (95% CI) for children below and above the 25th percentile for cobalamin were 0.53 (0.35-0.78) and 0.90 (0.73-1.11), respectively (P-interaction = 0.015). There were similar differences for the OR when comparing efficacy in those above and below the 75th percentile for tHcy and MMA (P-interaction = 0.045 and 0.188, respectively). Baseline folate status did not modify the effect of zinc on prolonged diarrhea. Neither cobalamin nor folate status influenced the effect of zinc on acute diarrhea. Children with poor cobalamin status benefited more from zinc supplementation for the prevention of prolonged diarrhea.

Zinc deficiency is common among healthy women of reproductive age in Bhaktapur, Nepal

Zinc deficiency is a major public health problem in many developing countries. However, its prevalence is still unknown in most populations. Women of reproductive age in developing countries are highly vulnerable to nutritional deficiencies, including that of zinc. To estimate the prevalence of zinc deficiency and to identify important dietary sources of zinc, we undertook a cross-sectional survey in 500 nonpregnant Nepalese women and measured their plasma zinc concentrations. We also examined the associations between plasma zinc and dietary intake of zinc or phytate, iron status, plasma concentrations of C-reactive protein, albumin, and hemoglobin. Food intake was estimated by 2 24-h dietary recalls and 1 FFQ for each woman. The plasma zinc concentration was (mean +/- SD) 8.5 +/- 2.4 micromol/L and more than three-quarters of the women were zinc deficient. Dietary zinc intake did not predict plasma zinc concentration, whereas phytate intake was negatively and significantly associated with plasma zinc. The other variables that were associated with plasma zinc were plasma albumin and hemoglobin concentration. Rice contributed 50% to the total estimated daily zinc intake and wheat and meat each contributed 15%. Rice also contributed 68% to the daily intake of phytate. In conclusion, we found that zinc deficiency was common in women of reproductive age and that the foods contributing substantial amounts of zinc also contributed importantly to the intake of phytate.

Effect of high dose oral zinc in mice with severe infection with Streptococcus pneumoniae

Zinc is important for normal function of the immune system and inflammation increases the demand for zinc. We hypothesized that high doses of zinc given during acute pneumococcal illness would alter the severity of infection. 24 six-week-old BALB/c mice were anaesthetized and infected intranasally with Streptococcus pneumoniae. Zinc intake was controlled by administering zinc through an intragastric tube. One group was given normal doses (5 microg/d) and the other group high doses of zinc (225 microg/d). We counted the number of bacteria from venous blood at 24 and 48 h, and from heart puncture and nasal wash at 72 h after intranasal challenge. Mice given excess zinc had 2.65 micromol/l, i.e. 25% higher (p= 0.05) mean plasma zinc concentration compared to those given normal amounts. 75% of mice in both groups developed pneumococcal bacteraemia. There were no differences in the numbers of S. pneumoniae colony forming units (CFUs) in blood or nasal wash between the groups. Thus, high doses of zinc did not alter the severity of systemic pneumococcal infection in mice.

Functional indicators for assessing zinc deficiency

Zinc is an essential micronutrient for growth and proper immune function. There is currently no simple recommendation for the assessment of population-level zinc deficiency. Trials of zinc supplementation have shown positive effects of supplementation on clinical outcomes and growth. We reviewed the results of randomized trials of zinc supplementation and correlation studies that assessed infectious diseases, growth, and development outcomes among children under 5 years of age. The results indicate that zinc supplementation decreases the incidence and prevalence of diarrhea and pneumonia, but the use of trial data to make population-level estimates of zinc deficiency is not practical and is difficult to quantify. The data also indicate that zinc supplementation increases growth, especially among children who are stunted. Stunting rates are commonly estimated and can be used to estimate zinc deficiency. Previous recommendations suggest that stunting rates at or above 20% should be indicative of zinc deficiency among children under 5 years of age. This review provides additional data and analysis to support the current recommendation.

Psychosocial and biochemical interactions in aging: preliminary results from an Italian old sample of "Zincage" project

The study of the interactions among biological factors and psychosocial conditions is a very innovative field, because data are lacking in the scientific literature. Among biological aspects, zinc is an essential element in the elderly, especially in relation to one of the proteins, such as albumin, involved in zinc transport into the cells. In this study, the aim is the assessment of the interrelationship between albumin value (used as an index of the body zinc status) and some psychosocial dimensions in elderly Italian sample recruited for ZINCAGE project, supported by the European Commission in the "Sixth Framework Programme". Some tests and questionnaires were administered to older people included in the trial: the "life-style questionnaire"; the mini mental state examination (MMSE); the geriatric depression scale (GDS-15 items). On the basis of the Senieur Protocol for gerontological studies, a sample of 291 Italian healthy old subjects has been recruited in Central Italy and divided into 3 age groups: (a) 125 subjects aged from 65 to 74 years, (b) 89 subjects aged from 75 to 84 years, (c) 77 subjects aged >or=85 years (classified like successful old people). No cognitive impairment assessed by MMSE was observed in 67.5% of the sample; 64.0% had GDS score less than 5, indicating no depression, whereas the prevalence of biological albumin deficiency (<3.5 g/dl) found in Italian old people was 21.0%. Sixty one percent of subjects with albumin deficiency displayed higher values of GDS (>or=5). These preliminary results showed an interrelationship among serum albumin value and psychosocial aspects in Italian old population, suggesting that low albumin values may be involved in impaired psychological dimensions.

Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy

In HIV-infected persons, low serum concentrations of vitamins and minerals, termed micronutrients, are associated with an increased risk of HIV disease progression and mortality. Micronutrient supplements can delay HIV disease progression and reduce mortality in HIV-positive persons not receiving highly active antiretroviral therapy (HAART). With the transition to more universal access to HAART, a better understanding of micronutrient deficiencies and the role of micronutrient supplements in HIV-positive persons receiving HAART has become a priority. The provision of simple, inexpensive micronutrient supplements as an adjunct to HAART may have several cellular and clinical benefits, such as a reduction in mitochondrial toxicity and oxidative stress and an improvement in immune reconstitution. We reviewed observational and trial evidence on micronutrients in HIV-positive persons receiving HAART to summarize the current literature and suggest future research priorities. A small number of observational studies have suggested that some, but not all, micronutrients may become replete after HAART initiation, and few intervention studies have found that certain micronutrients may be a beneficial adjunct to HAART. However, most of these studies had some major limitations, including a small sample size, a short duration of follow-up, a lack of adjustment for inflammatory markers, and an inadequate assessment of HIV-related outcomes. Therefore, few data are available to determine whether HAART ameliorates micronutrient deficiencies or to recommend or refute the benefit of providing micronutrient supplements to HIV-positive persons receiving HAART. Because micronutrient supplementation may cause harm, randomized placebo-controlled trials are needed. Future research should determine whether HAART initiation restores micronutrient concentrations, independent of inflammatory markers, and whether micronutrient supplements affect HIV-related outcomes in HIV-positive persons receiving HAART.

Effect of infections and environmental factors on growth and nutritional status in developing countries

Despite numerous advances and improvements in child health globally, malnutrition remains a major problem and underlies a significant proportion of child deaths. A large proportion of the hidden burden of malnutrition is represented by widespread single and multiple micronutrient deficiencies. A number of factors may influence micronutrient deficiencies in developing countries, including poor body stores at birth, dietary deficiencies and high intake of inhibitors of absorption such as phytates and increased losses from the body. Although the effects of poor intake and increased micronutrient demands are well described, the potential effects of acute and chronic infections on the body's micronutrient status are less well appreciated. Even more obscure is the potential effect of immunostimulation and intercurrent infections on the micronutrient distribution and homeostasis. The association therefore of relatively higher rates of micronutrient deficiencies with infectious diseases may be reflective of both increased predisposition to infections in deficient populations as well as a direct effect of the infection itself on micronutrient status indicators. Recently the association of increased micronutrient losses such as those of zinc and copper with acute diarrhea has been recognized and a net negative balance of zinc has been shown in zinc metabolic studies in children with persistent diarrhea. It is also recognized that children with shigellosis can lose a significant amount of vitamin A in the urine, thus further aggravating preexisting subclinical vitamin A deficiency. Given the epidemiological association between micronutrient deficiencies and diarrhea, supplementation strategies in endemic areas are logical. The growing body of evidence on the key role of zinc supplementation in accelerating recovery from diarrheal illnesses in developing countries supports its use in public health strategies.

Acute phase protein levels, T. trichiura, and maternal education are predictors of serum zinc in a cross-sectional study in Bangladeshi children

Zinc deficiency is a public health issue in Bangladesh. The objectives were to identify predictors of serum zinc concentration and to assess the prevalence of low serum zinc, in both the whole population, after correcting for the effect of serum C-reactive protein (CRP) (using multiple categories), and the healthy subgroup. A cross-sectional study was conducted among 579 apparently healthy 3-7 y old children from a Dhaka slum, Bangladesh. Using multiple linear regression, the effects of age, gender, serum CRP and alpha 1-antichymotrypsin, reported morbidity, Ascaris lumbricoides and Trichuris trichiura infections, parental education as well as stunting, underweight, and wasting on serum zinc were estimated. Serum zinc (mean +/- SD) was 9.7 +/- 1.1 micromol/L. Elevated serum CRP levels, T. trichiura infection, and stunting were negative predictors of serum zinc, whereas maternal education was a positive predictor. Compared with serum CRP <1 mg/L, CRP levels of 2 to <5, 5 to <10 and > or =10 mg/L were associated with 0.33, 0.73, and 0.89 micromol/L lower serum zinc, respectively. The prevalence of low serum zinc (<9.9 micromol/L) fell from 59.3 to 49.7% in the whole population, after correcting for the effect of CRP and was 50.0% in the healthy subgroup (CRP <2 mg/L). The prevalence of low serum zinc was high but overestimated due to the effect of the acute phase response. Interventions to address low serum zinc in Bangladesh are warranted. Controlling T. trichiura infection and improving maternal education may be important interventions. The use of multiple categories of acute phase proteins and cut-off values that indicate elevated levels warrant further research.

Psychosocial aspects and zinc status: is there a relationship with successful aging?

It is very interesting and innovative to study the interrelationships between biological characteristics, particularly zinc status, and psychosocial conditions in old age, because there are few and fragmentary data in the literature. The aim of this study was to examine the interrelationship between serum albumin value (an indicator of zinc status) and some psychosocial characteristics in elderly Italian volunteers recruited for the ZINCAGE project, which is supported by the European Commission in the Sixth Framework Programme (Food-CT-2003- 506850). A protocol of tests and questionnaires was used: the Lifestyle Questionnaire, the Mini-Mental Status Examination (MMSE), the Geriatric Depression Scale (GDS, 15 items), and the Perceived Stress Scale. A sample of 174 old subjects were recruited in Region Marche (Central Italy), and classified into three age groups: 65 to 74 years old, 75 to 84 years old, and >85 years old (including some nonagenarians). The preliminary results show that 69.7% of the subjects have no cognitive impairment; 66.5% have a value of the GDS scale indicating no depression; and 17% have an albumin deficiency. The majority of these are >85 years old and women. A relationship between level of albumin (used as indicator of zinc status) and depression has been found: 71% of subjects with albumin deficiency displayed a higher value on the depression test against 29% of subjects with a normal value (p < 0.01). These preliminary results show a relationship between serum albumin and psychological characteristics, in particular depression in an old Italian population. This further suggests that a zinc deficiency, via hypoalbumin values, is involved in impaired psychological characteristics in the elderly.

Zinc supplementation and serum zinc during diarrhea

OBJECTIVE

Zinc deficiency is very common in developing countries and is more pronounced during an episode of diarrhea. Supplementation with zinc improves diarrhea and might correct zinc deficiency in both the short and longer term.

METHOD

We conducted a nested study within a cluster randomized treatment trial. Fifty children with diarrhea living in the zinc treated clusters, 50 children with diarrhea living in control clusters, and 50 healthy children living in the control clusters were enrolled. We assessed serum zinc at the start of the diarrhea episode, which was 1-3 days after supplementation began in zinc treated children, and again one week after the diarrhea ended and supplementation ceased. Baseline characteristics and serum zinc concentration were assessed.

RESULTS

Serum zinc was low in 44% of healthy children at the first blood draw. Compared to healthy controls, serum zinc was 3.1 mmol/L higher among children with diarrhea who were supplemented with zinc at first blood draw and 1.3 mmol/L higher 3 weeks later.

CONCLUSION

Zinc supplementation enhances serum zinc concentration when given as a treatment for diarrhea and helps children maintain a more adequate zinc status during the convalescent period.

Plasma zinc concentrations are depressed during the acute phase response in children with falciparum malaria

Plasma concentrations of some micronutrients are altered in the setting of acute infectious or inflammatory stress. Previous studies have provided conflicting evidence concerning the extent and direction of changes in plasma zinc concentrations during the acute phase response. We carried out an observational cohort study in 689 children enrolled in a randomized trial of zinc supplementation during acute falciparum malaria in order to evaluate the relation between plasma zinc concentration and the acute phase response. Plasma zinc was measured by atomic absorption spectrophotometry. On admission, 70% of all subjects had low plasma zinc (<9.2 micromol/L). Multivariate analysis of predictors of admission plasma zinc showed that admission C-reactive protein (CRP), parasite density, and study site were the most important predictors. Predictors of changes in plasma zinc from admission to 72 h included baseline CRP, change in CRP, treatment group, study site, and baseline zinc concentration. In children with acute malaria infection, baseline plasma zinc concentrations were very low and were inversely correlated with CRP (r = -0.24, P < 0.0001) and the degree of parasitemia (r = -0.19, P < 0.0001). Even when CRP and time were taken into account, zinc supplementation increased plasma zinc concentration from admission to 72 h. When available, plasma zinc concentrations should be interpreted with concurrent measures of the acute phase response such as CRP. In children whose age, diet, and/or nutritional status place them at risk of zinc deficiency, those with low plasma zinc levels should be supplemented with oral zinc and followed for clinical and/or biochemical response.