Location: Children's Nutrition Research CenterTitle: Dietary cysteine is used more efficiently by children with severe acute malnutrition with edema compared with those without edema) Author
Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/24/2011
Publication Date: 1/5/2012
Citation: Badaloo, A., Hsu, J.W., Taylor-Bryan, C., Green, C., Reid, M., Forrester, T., Jahoor, F. 2012. Dietary cysteine is used more efficiently by children with severe acute malnutrition with edema compared with those without edema. American Journal of Clinical Nutrition. 95(1):84-90. Interpretive Summary: There are two main types of severe childhood malnutrition, kwashiorkor and marasmus. In kwashiorkor the child is not only severely malnourished but he/she also makes less of a very important compound called glutathione, has hair loss and skin erosion, and the gut is very thin because most of the gut tissue is eroded. All these tissues are rich in a compound called cysteine, which is part of the protein we eat in our meals. From previous studies we showed that children with kwashiorkor produce less cysteine than children with marasmus. We therefore wanted to find out whether children with kwashiorkor will use cysteine from their diet more efficiently, especially during the early stages of treatment when they are severely malnourished and have to repair and regrow their gut very quickly. We found that children with kwashiorkor used their dietary cysteine more efficiently than the children with marasmus, especially during the early and middle stages of treatment. This finding suggests that children with kwashiorkor have a greater requirement for cysteine during early and middle stages of nutritional rehabilitation. Based on this finding we have recommended that extra cysteine should be added to the diet fed during early treatment of children with kwashiorkor.
Technical Abstract: Children with edematous severe acute malnutrition (SAM) produce less cysteine than do their nonedematous counterparts. They also have marked glutathione (GSH) depletion, hair loss, skin erosion, gut mucosal atrophy, and depletion of mucins. Because GSH, skin, hair, mucosal, and mucin proteins are rich in cysteine, we hypothesized that splanchnic extraction and the efficiency of cysteine utilization would be greater in edematous than in nonedematous SAM. We aimed to measure cysteine kinetics in childhood edematous and nonedematous SAM. Cysteine flux, oxidation, balance, and splanchnic uptake (SPU) were measured in 2 groups of children with edematous (n = 9) and nonedematous (n = 10) SAM at 4.4 +/- 1.1 d after admission (stage 1) and at 20.5 +/- 1.6 d after admission (stage 2) when they had replenished 50% of their weight deficit. In comparison with the nonedematous group, the edematous group had slower cysteine flux at stage 1 but not at stage 2; furthermore, they oxidized less cysteine at both stages, resulting in better cysteine balance and therefore better efficiency of utilization of dietary cysteine. Cysteine SPU was not different between groups but was approx. 45% in both groups at the 2 stages. These findings suggest that children with edematous SAM may have a greater requirement for cysteine during early and mid-nutritional rehabilitation because they used dietary cysteine more efficiently than did their nonedematous counterparts and because the splanchnic tissues of all children with SAM have a relatively high requirement for cysteine.