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Functional anemia of complicated protein-energy malnutrition at high altitude
Insights
Severe protein-energy malnutrition (PEM) in Bolivian children impairs red blood cell production, worsening anemia at high altitudes. Iron and folate deficiencies significantly hinder recovery during refeeding.
Area of Science:
- Pediatric Nutrition
- High-Altitude Physiology
- Hematology
Background:
- Severe protein-energy malnutrition (PEM) affects vital physiological functions.
- High altitude (3700 m) presents unique physiological challenges, particularly regarding oxygen transport.
- Erythropoiesis, the process of red blood cell formation, is crucial for oxygen delivery.
Purpose of the Study:
- To investigate the impact of severe PEM on erythropoiesis in children at high altitude.
- To assess the contribution of iron and folate deficiency to anemia in this population.
- To understand the implications for oxygen transport and refeeding recovery.
Main Methods:
- Studied children with severe PEM at 3700 m in Bolivia.
- Compared hemoglobin, arterial oxygen tension, and oxygen-dissociation curves with high-altitude controls.
- Measured serum and erythrocyte folate, and transferrin saturation.
- Monitored changes during a 10-week refeeding period.
Main Results:
- Children with PEM exhibited 40% lower hemoglobin and reduced arterial oxygen tension.
- Oxygen-dissociation curve was right-shifted, indicating adaptation.
- Significantly lower serum and erythrocyte folate levels were observed.
- Iron status (transferrin saturation) worsened during refeeding, suggesting impaired iron supply.
Conclusions:
- Anemia from severe PEM severely impacts oxygen transport at high altitude, necessitating adaptive responses.
- Iron and folate deficiencies are major contributors to poor red blood cell response.
- Inflammation and nutrient deficiencies may impede recovery and tissue regeneration during refeeding.
Abstract:
The effect of severe protein-energy malnutrition (PEM) on erythropoiesis in children living in the highlands of Bolivia, altitude 3700 m, was studied. Forty percent reduced hemoglobin concentrations, significantly lower arterial oxygen tensions, and a right-shifted, oxygen-dissociation curve were observed compared to high-altitude controls. Serum and erythrocyte folate concentrations were 44% and 82%, respectively, of control values. Low initial transferrin saturation decreased significantly during the 10-wk refeeding period. Thus, iron and folate deficiency contributed significantly to the poor red cell response. Results suggest that the anemia associated with severe PEM has a more significant impact on oxygen transport at high altitude than at sea level and requires an adaptive response in the oxygen-dissociation curve to satisfy tissue-oxygen demands. Furthermore, marginal iron and folate status and an inflammatory block of iron supply may limit the reestablishment of a normal tissue mass during refeeding.