Effects of therapeutic zinc supplementation for diarrhea and two preventive zinc supplementation regimens on the incidence and duration of diarrhea and acute respiratory tract infections in rural Laotian children: A randomized controlled trial.

BACKGROUND: Diarrhea and respiratory tract infections are leading causes of childhood morbidity and mortality. This individually randomized, double-blind placebo-controlled trial was designed to evaluate the effects of different zinc supplementation regimens on the incidence and duration of diarrhea and acute lower (ALRI) and upper (AURI) respiratory tract infections among rural Laotian children. The study included 3407 children, 6-23 months at enrollment. METHODS: Children were randomized to one of four study groups: therapeutic zinc supplements for diarrhea treatment (20 mg/d for 10 days with each episode; TZ), daily preventive zinc tablets (7 mg/d; PZ), daily multiple micronutrient powder (10 mg/d zinc, 6 mg/d iron and 13 other micronutrients; MNP), or daily placebo powder for 9 months. Incidence and duration of diarrhea (≥3 liquid stools/24 hours), ALRI (persistent cough with wheezing, stridor or chest in-drawing) and AURI (purulent nasal discharge with cough) were assessed by parental report during weekly home visits and analyzed using negative binomial models. RESULTS: Baseline mean age was 14.2 ± 5.1 months, and 71% had low plasma zinc (<65 µg/dL). Overall diarrhea incidence (0.61 ± 0.01 episodes/100 days at risk) and duration (2.12 ± 0.03 days/episode) did not differ by study group. Age modified the impact of the interventions on diarrhea incidence (P = 0.06) and duration (P = 0.01). In children >18 months, TZ reduced diarrhea incidence by 24% vs MNP (P = 0.035), and 36% vs Control (P = 0.004), but there was no difference with PZ. This patterned remained when analyses were restricted to diarrhea episode occurring after the first treatment with TZ. Also, in children >18 months, TZ reduced diarrhea duration by 15% vs PZ (P = 0.03), and 16% vs Control (P = 0.03), but there was no difference with MNP. There were no overall effects of study group on incidence of ALRI (overall mean 0.005 ± 0.001 episodes/100 days, P = 0.14) or AURI (overall mean 0.09 ± 0.01 episodes/100 days, P = 0.72). CONCLUSIONS: There was no overall impact of TZ, PZ or MNP on diarrhea, ALRI and AURI. However, in children >18 months, TZ significantly reduced both the duration of diarrhea episodes and the incidence of future diarrhea episodes compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02428647.

Effects of Daily Zinc, Daily Multiple Micronutrient Powder, or Therapeutic Zinc Supplementation for Diarrhea Prevention on Physical Growth, Anemia, and Micronutrient Status in Rural Laotian Children: A Randomized Controlled Trial.

OBJECTIVES: To evaluate the optimal zinc supplementation strategy for improving growth and hematologic and micronutrient status in young Laotian children. STUDY DESIGN: In total, 3407 children aged 6-23 months were randomized to receive either daily preventive zinc tablets (7 mg/d), high-zinc, low-iron micronutrient powder (10 mg/d zinc, 6 mg/d iron, and 13 other micronutrients), therapeutic zinc supplementation for diarrhea (20 mg/d for 10 days per episode), or daily placebo powder; all were followed for ~9 months. Anthropometry, hemoglobin, zinc, and iron status were assessed at baseline and endline. Analyses were by intention-to-treat, using linear and modified Poisson regression. RESULTS: At baseline, mean (±SD) age was 14.2 ± 5.1 months and stunting and anemia prevalence were 37.9% and 55.6%, respectively. At endline, zinc deficiency in the preventive zinc (50.7%) and micronutrient powder (59.1%) groups were significantly lower than in the therapeutic zinc (79.2%) and control groups (78.6%; P < .001), with no impact on stunting (37.1%-41.3% across the groups, P = .37). The micronutrient powder reduced iron deficiency by 44%-55% compared with other groups (P < .001), with no overall impact on anemia (P = .14). Micronutrient powder tended to reduce anemia by 11%-16% among children who were anemic at baseline (P = .06). CONCLUSIONS: Despite improving zinc status, preventive zinc and micronutrient powder had no impact on growth. The micronutrient powder improved iron status and tended to reduce anemia among the subset of previously anemic children. TRIAL REGISTRATION: ClinicalTrials.govNCT02428647.

Impact of Two Forms of Daily Preventive Zinc or Therapeutic Zinc Supplementation for Diarrhea on Hair Cortisol Concentrations Among Rural Laotian Children: A Randomized Controlled Trial.

Zinc supplementation has been shown to reduce the morbidity burden among young children, and may reduce chronic stress. Hair cortisol has been promoted as an indicator of chronic stress. We assessed the impact of different strategies for delivering supplementary zinc on hair cortisol concentrations (HCC) in young Laotian children and examined risk factors associated with HCC. In a randomized double-blind controlled trial (NCT02428647), children aged 6⁻23 mo were randomized to one of four intervention groups and followed for ~36 weeks: daily preventive zinc (PZ) tablets (7 mg/day), daily multiple micronutrient powder (MNP) sachets (containing 10 mg zinc and 14 other micronutrients), therapeutic zinc (TZ) supplements for diarrhea treatment (20 mg/day for 10 days) or daily placebo powder. HCC of 512 children was assessed at baseline and endline. ANCOVA and linear regression models were used to assess group differences in HCC and to examine the risk factors associated with HCC, respectively. At enrollment, mean HCC was 28.8 ± 43.9 pg/mg. In models adjusted for age at enrollment, health district, and baseline HCC there was no overall effect of the interventions on endline HCC and change in HCC. When controlling for additional predetermined covariates, there was a marginally significant effect on change in HCC (p = 0.075) with a slightly lower reduction of HCC in TZ compared to PZ (mean change (95% CI): -4.6 (-7.0; -2.3) vs. -9.4 (-11.7; -7.0) pg/mg; p = 0.053). At baseline, consumption of iron rich foods was negatively associated with HCC, whereas AGP (α1-acid glycoprotein) levels, elevated AGP and C-reactive protein and high soluble transferrin receptor were positively associated with HCC. In young Laotian children, MNP, PZ and TZ had no impact on HCC. The marginal difference in change in HCC between the PZ and TZ groups was too small to be considered of health significance.

First Field Test of an Innovative, Wider Tape to Measure Mid-Upper Arm Circumference in Young Laotian Children.

BACKGROUND: Measurements of mid-upper arm circumference (MUAC) may result in measurement error due to incorrect placement along the arm or tight pulling of tape. To reduce the risk of these measurement errors, a new wider tape was developed. OBJECTIVE: To compare the measurement agreement and precision and the ease of use of the standard and wide MUAC tapes. METHODS: Mid-upper arm circumference was measured in 814 children aged 9 to 32 months with both tapes. The midpoint of the upper arm was measured with the standard tape and estimated with the wide tape. Standardization sessions were implemented to assess intra- and interobserver precision. RESULTS: Mid-upper arm circumference with the wide MUAC tape was significantly larger than the standard tape (mean [standard deviation]: 14.3 [1.0] cm vs 13.9 [1.0] cm; P < .001), resulting in a consistent bias of +0.41 cm. Forty-six (5.7%) children were identified with low MUAC <12.5 cm by standard tape compared with 10 (1.2%) by the wide tape ( P <.001). Because a new tape could be reproduced by correcting for this bias, we corrected measured results by subtracting 0.41 cm and mean MUAC by tape type was no longer significantly different. Intra- and interobserver technical error of measurement suggested a better precision with the wide MUAC tape. CONCLUSIONS: Despite simplifying the measurement by approximating the midpoint of the upper arm, the wide MUAC tape tended to have better precision than the standard MUAC tape. However, there was a consistent measurement bias of +0.41 cm in mean MUAC. This first field test yielded promising results and led to further product adjustments.