Zinc-MNP Trial for Prevention of Diarrhea and Promotion of Linear Growth

Randomized, Double-blind, Community-based Efficacy Trial of Various Doses of Zinc in Micronutrient Powders or Tablets in Young, Bangladeshi Children

International Centre for Diarrhoeal Disease Research, Bangladesh, Johns Hopkins Bloomberg School of Public Health, University of Colorado, Denver

This is a randomized, double-blind, community-based efficacy trial of different doses, forms, and frequencies of zinc supplementation for the prevention of diarrhea and promotion of linear growth among children 9-11 months of age in Dhaka, Bangladesh.

Zinc is essential to support growth in young children especially for tissues undergoing rapid cellular differentiation and turnover, such as those in the immune system and gastrointestinal tract. Therapeutic zinc supplementation has been initiated in low-income countries as part of diarrhea treatment programs to support these needs for young children but, the effects of preventive supplemental zinc as a tablet or as a multiple micronutrient powder (MNP) on child growth and diarrheal disease are mixed and pose programmatic uncertainties. Thus, a randomized, double-blind community-based efficacy trial of five different doses, forms, and frequencies of preventive zinc supplementation vs. a placebo was designed for a study in children aged 9-11 months in an urban community in Dhaka, Bangladesh. The primary outcomes of this 24-week study are incidence of diarrheal disease and linear growth. Study workers will conduct in-home morbidity checks twice weekly; anthropometry will be measured at baseline, 12 weeks and 24 weeks. Serum zinc and other related biomarkers will be measured in a subsample along with an estimate of the exchangeable zinc pool size using stable isotope techniques in a subgroup. Therapeutic zinc will be provided as part of diarrhea treatment, in accordance with Bangladesh's national policy. Therefore, the proposed study will determine the additional benefit of a preventive zinc supplementation intervention.

Standard MNP, 15 micronutrients (Vitamin A 400 µg, vitamin D 5 µg, vitamin E 5 mg, vitamin C 30 mg, thiamine 0.5 mg, riboflavin 0.5 mg, niacin 6 mg, pyridoxine 0.5 mg, vitamin B12 0.9 mg, folate 150 µg, iron 10 mg, zinc 4.1 mg, copper 0.56 mg, selenium 17.0 µg and iodine 90 µg). Daily supplementation for 24 weeks.

Same as group 1, except with 10 mg zinc instead of 4.1 mg and 6 mg iron instead of 10 mg. Daily supplementation for 24 weeks.

Same as study group 1, except with 10 mg zinc instead of 4.1 mg, and 6 mg iron and no iron on alternating days instead of 10 mg. Daily supplementation for 24 weeks.

10 mg zinc in a dispersible tablet. Daily supplementation for 14 days at baseline and 3 months, placebo tablet on all other days.

Change in the prevalence of stunting (LAZ <-2) in the study population over the 24-week follow-up period

Change in the prevalence of wasting (WLZ <-2) in the study population over the 24-week follow-up period

Dysentery is defined as any diarrheal episode in which the loose or watery stools contain visible red blood

Change in mean serum zinc concentration among children in the biochemistry sub-group over the 24-week follow-up period

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants in all 6 intervention groups

Change in the prevalence of zinc deficiency (serum zinc concentration <9.9 umol/L) in the biochemistry subgroup from baseline to the end of the 24-week follow-up period

Measured at enrollment and at the end of the 24-week follow-up period in subgroup of participants in all 6 intervention groups

Change in the exchangeable zinc pool size from enrollment to the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP group, dispersible zinc supplement group, and placebo group

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

Change in mean concentrations of ferritin from enrollment to the end of the 24-week follow-up period among participants in the biochemistry subgroup.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants in all 6 intervention groups

Change in mean concentrations of soluble transferrin receptor from enrollment to the end of the 24-week follow-up period among participants in the biochemistry subgroup.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants in all 6 intervention groups

Change in the composition of gut microbiota from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron; dispersible zinc supplement; and placebo powder groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

To compare the change in amino acid metabolites associated with gut permeability from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron MNP; dispersible zinc supplement; and placebo groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

To compare the change in lipid metabolites associated with gut permeability from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron MNP; dispersible zinc supplement; and placebo groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

To compare the change in genome wide gene expression, measured with RNA-sequencing, from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron MNP; dispersible zinc supplement; and placebo groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

To compare the change in specific gene expression, measured by quantitative Polymerase Chain Reaction, from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron MNP; dispersible zinc supplement; and placebo groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

To compare the change in cellular immune function by leukocyte profiles, from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron MNP; dispersible zinc supplement; and placebo groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

To compare the change in serum cytokines, measured by Luminex analysis, from enrollment to the end of the 24-week follow-up period among a subgroup of participants randomized to the high zinc, low-iron MNP; dispersible zinc supplement; and placebo groups.

Measured at enrollment and at the end of the 24-week follow-up period in a subgroup of participants randomized to the high zinc, low-iron MNP, dispersible zinc supplement, and placebo groups.

Inclusion Criteria: 9-11 months of age Weight-for-length Z score >= -3 according to the 2006 World Health Organization Growth Standards Hemoglobin concentration > = 7.0 g/dL Exclusion Criteria: Presence of severe acute malnutrition, defined as a WLZ <-3 and/or the presence of bipedal edema and/or mid-upper arm circumference <115 mm; Presence of severe anemia, defined as a hemoglobin concentration < 7.0 g/dL Congenital anomalies (e.g. cardiac defects, cleft lip or palate) or any other conditions that interfere with feeding; Chromosomal anomalies and other organic problems (e.g. jaundice, tuberculosis) Currently consuming MNPs with no intention of stopping

Islam MM, Black RE, Krebs NF, Westcott J, Long J, Islam KM, Peerson JM, Sthity RA, Khandaker AM, Hasan M, El Arifeen S, Ahmed T, King JC, McDonald CM. Different Doses, Forms, and Frequencies of Zinc Supplementation for the Prevention of Diarrhea and Promotion of Linear Growth among Young Bangladeshi Children: A Six-Arm, Randomized, Community-Based Efficacy Trial. J Nutr. 2022 May 5;152(5):1306-1315. doi: 10.1093/jn/nxab439.