The Vicious Cycle of Diarrhea andMalnutrition: Nutritional Risk Factors             Robert E. Black, MD, MPH         Edgar...
Potential Conflicts of Interest• Robert Black has documented that he has  no financial relationships to disclose or  Confl...
Outline of Presentation• Vicious Cycle of Diarrhea and Malnutrition• Underweight, stunting and wasting• Vitamin A deficien...
Undernutrition and Infection Vicious Cycle
Nutritional Status by Anthropometric Measuresand Childhood Mortality Risk
178 Million Children Under 5 Suffer from Stunting  Prevalence of    Stunting   No Data   <20%   20-29.9%   30-39.9%   ≥40%
Datasets Included in the Analyses ofAnthropometric Measures and Child MortalityBangladesh, Ghana, GuineaBissau, India, Ind...
Increased Risk of Child Mortality with Mild Stunting (-2 to < -1z)        Versus Adequate Height-For-Age (WHO 2006)
Increased Risk of Child Mortality with Moderate Stunting(-3 to < -2z) Versus Adequate Height-For-Age (WHO 2006)
Increased Risk of Child Mortality with Severe Stunting (< -3z)       Versus Adequate Height-For-Age (WHO 2006)
Risk of Child Mortality by Anthropometric            Measures Using the WHO Standard                    < -3z             ...
Risk of Child Diarrhea Mortality by Anthropometric           Measures Using the WHO Standard                    < -3z     ...
Vitamin AIntervention Effectsas Estimate of Risk
Distribution of Global Vitamin A Deficiency   Vitamin A deficient
Vitamin A Supplementation Trials:           ~165,000 Children;~23% Reduction in Preschool Child Mortality                 ...
Effect of Vitamin A Supplementation       on Child Diarrhea DeathsImdad et al. BMC Public Health 2011
Relative Risk of Diarrhea Mortality          Due to Vitamin A Deficiency• Inverse of risk reduction in trials- RR: 1.4 (95...
Zinc Intervention Effects  as Estimate of Risk
National Risk of Zinc Deficiency Based onPrevalence of Stunting Among Children Under 5   and Absorbable Zinc Content of th...
Trial of Zinc Supplementation in India:         Effects on Diarrhea Incidence• Age group: 6-35 months• Dose of zinc: 10 mg...
Trials Evaluating the Preventive Effects of Zinc         Supplementation on Diarrhea• Countries: Bangladesh (4), Burkina F...
Effect of Preventive Zinc Supplementation                on Incidence of Diarrhea    Meta-analysis of 33 comparisons*Overa...
Preventive Effect of Zinc    Supplementation on Child MortalityTielsch et al., Lancet 2007
Preventive Effect of Zinc Supplementation on  Mortality in Children 12-47 Months of Age   Tielsch et al., Lancet 2007
Relative Risk of Diarrhea Morbidity and Mortality  Due to Zinc Deficiency in Children < 5 y Old• Inverse of risk reduction...
Conclusions• Underweight, stunting and wasting are risk  factors for diarrhea mortality• Deficiencies of vitamin A and zin...
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The Vicious Cycle of Diarrhea and Malnutrition: Nutritional Risk Factors

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The Vicious Cycle of Diarrhea and Malnutrition: Nutritional Risk Factors

  1. 1. The Vicious Cycle of Diarrhea andMalnutrition: Nutritional Risk Factors Robert E. Black, MD, MPH Edgar Berman Professor and Chair Department of International Health
  2. 2. Potential Conflicts of Interest• Robert Black has documented that he has no financial relationships to disclose or Conflicts of Interest to resolve.• He has documented that his presentation will not involve discussion of unapproved, off-label, experimental or investigational drugs.
  3. 3. Outline of Presentation• Vicious Cycle of Diarrhea and Malnutrition• Underweight, stunting and wasting• Vitamin A deficiency• Zinc deficiency
  4. 4. Undernutrition and Infection Vicious Cycle
  5. 5. Nutritional Status by Anthropometric Measuresand Childhood Mortality Risk
  6. 6. 178 Million Children Under 5 Suffer from Stunting Prevalence of Stunting No Data <20% 20-29.9% 30-39.9% ≥40%
  7. 7. Datasets Included in the Analyses ofAnthropometric Measures and Child MortalityBangladesh, Ghana, GuineaBissau, India, Indonesia,Nepal, Peru, Philippines,Senegal, Sudan
  8. 8. Increased Risk of Child Mortality with Mild Stunting (-2 to < -1z) Versus Adequate Height-For-Age (WHO 2006)
  9. 9. Increased Risk of Child Mortality with Moderate Stunting(-3 to < -2z) Versus Adequate Height-For-Age (WHO 2006)
  10. 10. Increased Risk of Child Mortality with Severe Stunting (< -3z) Versus Adequate Height-For-Age (WHO 2006)
  11. 11. Risk of Child Mortality by Anthropometric Measures Using the WHO Standard < -3z -3 to < -2z -2 to < -1z (95% CI) (95% CI) (95% CI)Weight-for-age 10.8 (6.7-17.4) 3.0 (2.1-4.3) 1.7 (1.2-2.4)Height-for-age 5.7 (4.0-8.1) 2.4 (1.7-3.4) 1.5 (1.1-2.1)Weight-for-height 13.4 (7.8-19.8) 3.4 (2.4-4.9) 1.7 (1.2-2.3)
  12. 12. Risk of Child Diarrhea Mortality by Anthropometric Measures Using the WHO Standard < -3z -3 to < -2z -2 to < -1z (95% CI) (95% CI) (95% CI)Weight-for-age 11.6 (8.6-15.5) 2.9 (2.0-4.0) 1.7 (1.2-2.4)Height-for-age 6.3 (4.6-8.7) 2.4 (1.7-3.3) 1.7 (1.2-2.3)Weight-for-height 12.3 (9.2-16.6) 3.4 (2.5-4.6) 1.6 (1.2-2.1)
  13. 13. Vitamin AIntervention Effectsas Estimate of Risk
  14. 14. Distribution of Global Vitamin A Deficiency Vitamin A deficient
  15. 15. Vitamin A Supplementation Trials: ~165,000 Children;~23% Reduction in Preschool Child Mortality Black bars: p<0.05 White bars: NS Beaton et al. 1992
  16. 16. Effect of Vitamin A Supplementation on Child Diarrhea DeathsImdad et al. BMC Public Health 2011
  17. 17. Relative Risk of Diarrhea Mortality Due to Vitamin A Deficiency• Inverse of risk reduction in trials- RR: 1.4 (95% CI 1.2-1.7)• Applied to populations at risk of vitamin A deficiency such as those where trials were done
  18. 18. Zinc Intervention Effects as Estimate of Risk
  19. 19. National Risk of Zinc Deficiency Based onPrevalence of Stunting Among Children Under 5 and Absorbable Zinc Content of the Food Supply Category of Zinc deficiency % at Risk of inadequate zinc intake Stunting High  25  20% Intermediate >15 <25 >10 <20% Low 15 10% International Zinc Nutrition Consultative Group, Food Nutr Bull, 2004
  20. 20. Trial of Zinc Supplementation in India: Effects on Diarrhea Incidence• Age group: 6-35 months• Dose of zinc: 10 mg/d• In children 6-11 months old, no effect on diarrhea• In children 12-35 months old, diarrhea incidence reduced by 35% in boys and 19% in girls Sazawal, Black, Bhan et al. AJCN 1997
  21. 21. Trials Evaluating the Preventive Effects of Zinc Supplementation on Diarrhea• Countries: Bangladesh (4), Burkina Faso, Chile (2), China (2), Ecuador (3), Ethiopia (2), the Gambia, Guatemala, India (6), Jamaica, Mexico (4), Peru (3), S Africa, USA, Vietnam• Age groups: 1-60 mo• Dose of zinc: ≈10mg/d (range 3.5-20 mg/d) or 20-70 mg once per week• Zinc vs. placebo or some trials gave selected vitamins and/or minerals to both groups• 33 comparisons involving 16,665 children Brown et al. Food Nutr Bull 2009
  22. 22. Effect of Preventive Zinc Supplementation on Incidence of Diarrhea Meta-analysis of 33 comparisons*Overall Incidence Log RR = 0.80 (0.71 – 0.90) Mean Initial Age highly associated with magnitude of the effect of Zn supplementation (p<.0001) Analysis by sub-population > 12 mo Incidence Log RR = 0.73 (0.61- 0.87)* There was significant heterogeneity among studies (p<.0001) Brown et al. Food Nutr Bull 2009
  23. 23. Preventive Effect of Zinc Supplementation on Child MortalityTielsch et al., Lancet 2007
  24. 24. Preventive Effect of Zinc Supplementation on Mortality in Children 12-47 Months of Age Tielsch et al., Lancet 2007
  25. 25. Relative Risk of Diarrhea Morbidity and Mortality Due to Zinc Deficiency in Children < 5 y Old• Inverse of risk reduction in trials- RR for diarrhea incidence: 1.3 (95% CI 1.2-1.6)- RR for diarrhea mortality: 1.2 (95% CI 0.95-1.6)• Applied to populations at risk of zinc deficiency such as those where trials were done
  26. 26. Conclusions• Underweight, stunting and wasting are risk factors for diarrhea mortality• Deficiencies of vitamin A and zinc are risk factors for diarrhea mortality and zinc for diarrhea incidence• A substantial disease burden in children can be attributed to these risk factors

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