role of zinc in diahorrea

ROLE OF ZINC IN DIAHHOREAL DISEASES

DR.NEHAL VAIDYA

DCH

Introduction

• Acute gastroenteritis: a very common illness

among infants and children throughout world.

• In India poor sanitation, lack of safe drinking

water, overcrowding & poverty are factors that

make diarrheal disorders more frequent.

Diarrhea: Definition

• Stool weight > 250 gm each day: impractical.

• Hence, working definition of diarrhea includes:

-- ↑ stool frequency (>2-3 motions per day) or

-- Passage of loose, unformed stools.

Acute diarrhea

• Occurrence of 3 or more unformed (loose)

stools per day, for fewer than 14 days.

• Acute diarrhea accounts for 35 %, dysentery for

another 20 % of total diarrheal deaths.

Childhood diarrhea: Rx

• Oral rehydration supplements (O.R.S.): corrects

dehydration

• Antibiotics: Combat bacterial infection

• Probiotics: Useful non-pathogenic bacteria which

compete with harmful bacteria in intestine & inhibit

their growth. E.g. Lactobacilli

• Anti-hypersecretory: Racecadotril (Trotz)

• Nutritional supplements like zinc which boost

immunity.

Role of Zinc in health & disease 1. Immune booster: Zinc deficiency rapidly ↓ antibody- & cell-

mediated immune responses. Short periods of zinc supplementation substantially improve immune defense.

2. Anti-oxidant function: Superoxide radicals reduced to hydrogen peroxide by superoxide dismutases in presence of zinc co-factors.Efficient removal of these superoxide free radicals maintains integrity of membranes, ↓ risk of cancer, & slows aging process.

3. Growth: Zinc deficiency limits growth in young children & has been shown to affect fetal growth in animal models. In infants that were born small for gestational age (SGA) or preterm, positive effect of zinc supplementation on growth was shown.

Zinc & Immunity• Studies have shown that Zn deficiency rapidly

antibody- & cell-mediated responses in both humans & animals.

• Moderate deficiencies in Zn occur in sickle cell anemia, renal disease, chronic gastrointestinal disorders & acrodermatitis enteropathica; HIV; children with diarrhea; & elderly persons.

• Such Zn deficiency greatly alters host defense systems, leading to in in opportunistic infections & mortality rates.

• Conversely, short periods of Zn supplementation substantially improve immune defense in individuals with these diseases.

Zinc & Immunity• Data from animal studies clearly demonstrate that

immune integrity is tightly linked to Zn status.• Lymphopenia & thymic atrophy - early hallmarks of Zn

deficiency – are due to high losses of precursor T & B cells in the bone marrow.

• Glucocorticoid-mediated apoptosis induced by Zn deficiency causes down-regulation of lymphopoiesis.

• Zn itself can modulate death processes in precursor lymphocytes.

• Evidence show that Zn supplementation may impact of many of the diseases mentioned above by preventing dismantling of immune system.

Effect of Zn on immunity

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Indian Pediatr. 1997 Jul;34(7):589-97

Zinc and Diarrhea• Significant ↓ in both tissue & serum Zn common in acute and

chronic diarrhea.

• Zinc depletion occurs in diarrhea, more so in chronic state.

• Significant negative correlation between serum zinc & diarrheal duration.

• In a study, mean serum and tissue zinc levels in children with acute and chronic diarrhea were found to be significantly lower than healthy and infected controls.

• Zinc supplements have been shown to have a beneficial effect on acute diarrhea in children.

• It is reported that zinc supplementation leads to accelerated regeneration of intestinal mucosa, ↑ levels of brush-border enzymes, ↑ cellular immunity & ↑ levels of secretory antibodies.

Features of zinc deficiency

• Dermatitis

• Alopecia

• Diarrhea

• Dwarfism

• Hypogonadism

• Low growth rates

• Hypogeusia. (Taste disturbance)

Effects of Zinc supplementation• Improving Zn status ↓ morbidity from diarrheal &

respiratory infection.

Zinc supplementation leads to:

• Accelerated regeneration of mucosa

• Increased levels of brush-border enzymes

• Enhanced cellular immunity

• Higher levels of secretory antibodies.

• In stunted children, Zn supplementation results in enhanced catch-up growth via higher levels of insulin-like growth factor-I (IGF-1)

Zn supplements: Diarrhea & infections

• Zinc an adjunctive Rx • Not a replacement to important Rxs like ORS in AD.

Zn supplements in children useful in:• Dietary intake low in absorbable zinc• Severe stunting• Low plasma zinc• Persistent diarrhea. • Inadequate Zn intakes highly prevalent in developing

countries, especially during period of complementary feeding when Zn requirements are high & breast milk contributes little.

Zinc supplement in diarrhea & infections

RCTs show that

• Zn-supplemented children had lower rates of diarrhea,

pneumonia & malaria compared to children not given

Zn.

• Zn used as an adjunct to fluid & dietary management

of AD & PD found to ↓ diarrheal duration & severity

• Hence, Zn supplement useful as preventive &

therapeutic intervention in developing countries as

zinc deficiency is prevalent.

Role of Zinc in reducing diarrheal morbidity in children

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Efficacy of Zn supplements in continous trials

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Diarrheal incidence Diarrheal Prevalence Pneumonia

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Efficacy of Zn supplements in short course trials

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Efficacy of zinc in reducing stool output

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Stool output Stool output

Gm

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Zinc Control

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Effect of zinc on time of recovery

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Arch Dis Child. 1997 Sep;77(3):196-200

25% reduction in time to recovery

Effect of zinc on weight gain

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400% increase in w

t. gain

Effects of zinc supplements on incidence of Diarrhea

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Zinc PlaceboLancet 2005; 366 (9490):999-1004

Effects of zinc supplements on incidence of Pneumonia

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Effects of zinc supplements on incidence of Deaths

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Effects of zinc supplements on incidence of Pneumonia-realted deaths

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Effects of zinc supplements on Diarrheal incidence in LBW children < 1 yr

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Zinc PlaceboPediatrics 2003 Dec;112(6 Pt 1):1327-32

Thank You

role of zinc in diahorrea

Health & Medicine

Transcript of role of zinc in diahorrea