Zinc deficiency and supplementation in HIV/AIDS

[Association between intracellular zinc levels and nutritional status in HIV-infected and uninfected children exposed to the virus]

INTRODUCTION

Malnutrition, growth retardation and opportunistic infections outlast the metabolic, immune and gastrointestinal disorders produced by HIV. Zinc deficiency has been associated with deteriorating nutritional status, growth failure, and risk of infection. The aim of this study is to determine the association between zinc levels in peripheral blood mononuclear cells (PBMC) and the nutritional status of HIV-infected and uninfected children exposed to the virus.

PATIENTS AND METHODS

An analytical, observational, cross-sectional study was conducted on 17 infected and 17 exposed children, aged 2-10 years. Anthropometric measurements, clinical and nutritional history, 24h recall, measurement of physical activity, and zinc in PBMC by flow cytometry analysis were recorded.

RESULTS

Height according to age, energy consumption and adequacy of energy, protein and dietary zinc were significantly higher in children exposed to the virus compared to those infected with HIV (P <.05). No significant differences were found in BMI, levels of zinc in monocytes, CD4 + and CD4- lymphocytes between the two study groups (P >.05). However, the median levels of zinc in monocytes of infected patients was higher (218.6) compared to the control group (217.0). No association was found between zinc intake and levels of intracellular zinc.

CONCLUSIONS

The deterioration of nutritional status and growth retardation in children were associated with HIV, but not with the levels of intracellular zinc. The dietary intake of this nutrient was not associated with levels of zinc in monocytes or CD4 + and CD4- lymphocytes.

Zinc: role in immunity, oxidative stress and chronic inflammation

PURPOSE OF REVIEW

Zinc is essential for multiple cellular functions including immunity. Many investigators have used zinc supplementation in an attempt to affect the outcome of various diseases. These efforts were aimed at either supporting immunity by zinc administration or correcting the zinc dependent immune functions in zinc deficient individuals.

RECENT FINDINGS

In this review, recent findings of zinc supplementation in various diseases have been presented. Beneficial therapeutic response of zinc supplementation has been observed in the diarrhea of children, chronic hepatitis C, shigellosis, leprosy, tuberculosis, pneumonia, acute lower respiratory tract infection, common cold, and leishmaniasis. Zinc supplementation was effective in decreasing incidences of infections in the elderly, in patients with sickle cell disease (SCD) and decreasing incidences of respiratory tract infections in children. Zinc supplementation has prevented blindness in 25% of the elderly individuals with dry type of AMD. Zinc supplementation was effective in decreasing oxidative stress and generation of inflammatory cytokines such as TNF-alpha and IL-1beta in elderly individuals and patients with SCD.

SUMMARY

Zinc supplementation has been successfully used as a therapeutic and preventive agent for many conditions. Zinc functions as an intracellular signal molecule for immune cells.

Safety and efficacy of zinc supplementation for children with HIV-1 infection in South Africa: a randomised double-blind placebo-controlled trial

BACKGROUND

Zinc deficiency is associated with impaired immune function and an increased risk of infection. Supplementation can decrease the incidence of diarrhoea and pneumonia in children in resource-poor countries. However, in children with HIV-1 infection, the safety of zinc supplementation is uncertain. We aimed to assess the role of zinc in HIV-1 replication before mass zinc supplementation is recommended in regions of high HIV-1 prevalence.

METHODS

We did a randomised double-blind placebo-controlled equivalence trial of zinc supplementation at Grey's Hospital in Pietermaritzburg, South Africa. 96 children with HIV-1 infection were randomly assigned to receive 10 mg of elemental zinc as sulphate or placebo daily for 6 months. Baseline measurements of plasma HIV-1 viral load and the percentage of CD4+ T lymphocytes were established at two study visits before randomisation, and measurements were repeated 3, 6, and 9 months after the start of supplementation. The primary outcome measure was plasma HIV-1 viral load. Analysis was per protocol.

FINDINGS

The mean log(10) HIV-1 viral load was 5.4 (SD 0.61) for the placebo group and 5.4 (SD 0.66) for the zinc-supplemented group 6 months after supplementation began (difference 0.0002, 95% CI -0.27 to 0.27). 3 months after supplementation ended, the corresponding values were 5.5 (SD 0.77) and 5.4 (SD 0.61), a difference of 0.05 (-0.24 to 0.35). The mean percentage of CD4+ T lymphocytes and median haemoglobin concentrations were also similar between the two groups after zinc supplementation. Two deaths occurred in the zinc supplementation group and seven in the placebo group (p=0.1). Children given zinc supplementation were less likely to get watery diarrhoea than those given placebo. Watery diarrhoea was diagnosed at 30 (7.4%) of 407 clinic visits in the zinc-supplemented group versus 65 (14.5%) of 447 visits in the placebo group (p=0.001).

INTERPRETATION

Zinc supplementation of HIV-1-infected children does not result in an increase in plasma HIV-1 viral load and could reduce morbidity caused by diarrhoea.

RELEVANCE TO PRACTICE

Programmes to enhance zinc intake in deficient populations with a high prevalence of HIV-1 infection can be implemented without concern for adverse effects on HIV-1 replication. In view of the reductions in diarrhoea and pneumonia morbidity, zinc supplementation should be used as adjunct therapy for children with HIV-1 infection.

Efeitos da suplementação com zinco sobre o crescimento, sistema imunológico e diabetes

O zinco apresenta funções catalíticas, estruturais e reguladoras, sendo componente de várias enzimas. Os sintomas observados na deficiência deste elemento incluem lesões de pele, anorexia, retardo do crescimento, hipogonadismo e alteração na função imune. O objetivo desta revisão foi apresentar as funções metabólicas e funcionais do zinco, enfatizando as conseqüências da deficiência e os aspectos que justificam os estudos envolvendo a suplementação com zinco e seus efeitos sobre o crescimento, sistema imunológico e diabetes. Considerando que algumas doenças predispõem o organismo à deficiência de zinco, a suplementação, isoladamente ou associada a outros elementos, demonstra benefícios, especialmente no aumento da velocidade de crescimento, funcionamento do sistema imunológico, diminuição das afecções respiratórias e controle das diarréias. A suplementação em pacientes com diabetes está relacionada com as variáveis do controle metabólico e as concentrações plasmáticas e eritrocitárias de zinco. As estratégias de suplementação com zinco, em populações de risco, devem ser implementadas, considerando-se as doses adequadas de ingestão.