Hemoglobin Levels and the Risk of Malaria in Papua New Guinean Infants: A Nested Cohort Study

Studies are available that assess the risk of malaria in accordance to the body's iron store and the systematic iron supplementation of preschool children. However, only a few studies evaluated the temporal association between hemoglobin and malaria and their results are opposing. A total of 1,650 3-month-old Papua New Guinean infants were enrolled in this study and followed-up for 12 months. The risk of malaria was assessed in all children every 3 months and with each episode of fever. The incidence of clinical malaria between 3 and 15 months of age was 249 cases per 1,000 infants per year. After adjustment for potential confounding factors, a decrease of 1 g/dL of hemoglobin was associated with a nonsignificant increase of 11% for risk of malaria infection (hazard ratio, 1.11, 95% confidence interval; CI, 0.99-1.25, P = 0.076). Only children with severe anemia (hemoglobin < 8.0 g/dL) at baseline were at higher risk of malaria infection (hazard ratio, 1.72, 95% CI, 1.08-2.76, P = 0.023) during the follow-up year compared with the control group (Hemoglobin > 10.0 g/dL). This association was not statistically significant if only clinical malaria episodes were taken into account (hazard ratio, 1.42, 95% CI, 0.77-2.61, P = 0.26). Our study suggests that infants with lower hemoglobin levels are not protected against malaria infection. Further research that examines the risk of malaria in relation to both hemoglobin and iron store levels would be important to better understand this complex interaction.

Maize porridge enriched with a micronutrient powder containing low-dose iron as NaFeEDTA but not amaranth grain flour reduces anemia and iron deficiency in Kenyan preschool children

Few studies have evaluated the impact of fortification with iron-rich foods such as amaranth grain and multi-micronutrient powder (MNP) containing low doses of highly bioavailable iron to control iron deficiency anemia (IDA) in children. We assessed the efficacy of maize porridge enriched with amaranth grain or MNP to reduce IDA in Kenyan preschool children. In a 16-wk intervention trial, children (n = 279; 12-59 mo) were randomly assigned to: unrefined maize porridge (control; 4.1 mg of iron/meal; phytate:iron molar ratio 5:1); unrefined maize (30%) and amaranth grain (70%) porridge (amaranth group; 23 mg of iron/meal; phytate:iron molar ratio 3:1); or unrefined maize porridge with MNP (MNP group; 6.6 mg iron/meal; phytate:iron molar ratio 2.6:1; 2.5 mg iron as NaFeEDTA). Primary outcomes were anemia and iron status with treatment effects estimated relative to control. At baseline, 38% were anemic and 30% iron deficient. Consumption of MNP reduced the prevalence of anemia [-46% (95% CI: -67, -12)], iron deficiency [-70% (95% CI: -89, -16)], and IDA [-75% (95% CI: -92, -20)]. The soluble transferrin receptor [-10% (95% CI: -16, -4)] concentration was lower, whereas the hemoglobin (Hb) [2.7 g/L (95% CI: 0.4, 5.1)] and plasma ferritin [40% (95% CI: 10, 95)] concentrations increased in the MNP group. There was no significant change in Hb or iron status in the amaranth group. Consumption of maize porridge fortified with low-dose, highly bioavailable iron MNP can reduce the prevalence of IDA in preschool children. In contrast, fortification with amaranth grain did not improve iron status despite a large increase in iron intake, likely due to high ratio of phytic acid:iron in the meal.