Effectiveness of intermittent iron and high-dose vitamin A supplementation on cognitive development of school children in southern Ethiopia: a randomized placebo-controlled trial.

BACKGROUND: Iron is an essential mineral whose deficiency results in cognitive alteration, impaired emotional behaviors, and altered myelination and neurotransmission. In animal models, it has been shown that vitamin A (VA) could affect cognition. OBJECTIVES: The study aimed to evaluate the effectiveness of intermittent iron and VA supplementation on cognitive development of schoolchildren, and to assess the interaction between these supplementations. METHODS: Considering a 2 × 2 factorial design, 504 children were randomly assigned to 1 of the 4 arms: placebo VA and placebo iron supplement; high-dose vitamin VA and placebo iron supplement; iron supplement and placebo VA; and iron and high-dose vitamin VA supplements. Cognitive development was assessed using Raven's Coloured Progressive Matrices, digit span, Tower of London, and visual search tasks. RESULTS: The mean [± standard deviation (SD)] age of the enrolled children was 9.6 (±1.6) y. One-fifth of the children had iron deficiency or anemia, whereas 2.9%, 3.9%, and 12.1% of children had low iron stores, iron deficiency anemia, and VA deficiency, respectively. Intermittent iron supplementation did not result in any significant improvement of children's cognitive development and had a negative effect on the performance index of the visual search task compared with placebo (-0.17 SD, 95% confidence interval: -0.32, -0.02). Effects were evident among children with stunting, thinness, or children coming from understimulating home environments. High-dose VA supplementation resulted in a significant improvement of digit span z-score with a mean difference of 0.30 SD (95% confidence interval: 0.14, 0.46) compared with placebo VA. VA had a more beneficial impact for girls, children infected with helminths, and those from food secure households. CONCLUSION: In a population where the prevalence of iron deficiency is low, intermittent iron supplementation did not have any or negative effect on the child's cognitive development outcomes. Conversely, VA supplementation improved the child's working memory. TRIAL REGISTRATION NUMBER: The study is registered at clinicaltrials.gov as NCT04137354 (https://clinicaltrials.gov/study/NCT04137354).

Prevalence of hypertension and associated factors among adult residents in Arba Minch Health and Demographic Surveillance Site, Southern Ethiopia.

Hypertension is the leading risk factor for mortality and it is also one of the major risk factors for other non-communicable diseases (NCDs). The objective of the study was to assess the prevalence of hypertension and its associated factors among adults residing in Arba Minch health and demographic surveillance site (HDSS), Southern Ethiopia. A community-based cross-sectional survey was conducted in 2017 on the estimated sample size of 3,368 adults at Arba Minch Health and Demographic Surveillance site (HDSS). Data were collected using the WHO STEPS survey tools. Bivariate analysis was done to detect candidate variables at P-value less than 0.25 and entered into the final model to identify the independent predictors of hypertension. The prevalence of hypertension was 18.92% (95% CI: 17.63-20.28). The magnitude increase among respondents in the older age group [AOR 1.39 (95%CI: 1.05-1.84), 1.68 (95% CI: 1.26-2.23) and 2.67 (95%CI: 2.01-3.56) for age group 35-44, 45-54 and 55-64, respectively, compared to 25-34 years old group] and those with the higher wealth index [AOR 1.86 (95%CI: 1.33-2.59), 2.68 (95% CI: 1.91-3.75) and 2.97 (95%CI: 2.08-4.25) for 3rd quantile, 4th quantile and 5th quantile, respectively, compared to 1st quantile]. The odds of hypertension reduce among married participants (AOR 0.66, 95%CI: 0.51-0.85). Respondents with overweight (AOR 1.44, 95%CI: 1.02-2.02), khat chewing (AOR3.31, 95%CI: 1.94-5.64), low fruit and/or vegetable consumption (AOR 1.27, 95%CI: 1.05-1.53) and those who do not use coffee and tea (AOR 1.52, 95%CI: 1.03-2.24) had significantly higher likelihood of hypertension. Nearly one out of five participants have hypertension in this population. As hypertension is one of the silent killers, it is advisable to develop a system for enabling early detection and monitoring in the older age groups and overweight individuals.