Whole-body protein kinetics in marasmus and kwashiorkor during acute infection.

Marasmus and kwashiorkor are clinically distinct manifestations of severe malnutrition. This study tested the hypothesis that rates of whole-body protein synthesis and breakdown are higher in marasmus than in kwashiorkor during acute infection. We measured whole-body protein kinetics using stable isotope tracers in eight children with marasmus and acute infection (pneumonia or malaria) to determine the rate of appearance of urea and leucine in plasma. Serum concentrations of total protein, albumin, and C-reactive protein were also measured. These findings were compared with those reported previously for 13 children with kwashiorkor (including marasmic kwashiorkor) and acute infection who were studied with the same methods. HIV infection was present in 10 of 21 children. Rates of protein breakdown and synthesis were higher in marasmus than in kwashiorkor (227 +/- 59 compared with 103 +/- 30 micromol leucine x kg(-1) x h(-1) and 216 +/- 60 compared with 97 +/- 30 micromol leucine x kg(-1) x h(-1), P < 0.001). The concentration of globulin (total protein minus albumin) was higher in marasmus than kwashiorkor (40 +/- 17 compared with 25 +/- 7 g/L, P < or = 0.01), but C-reactive protein was not different (73 +/- 79 compared with 83 +/- 89 mg/L). HIV infection and body composition did not explain the differences between marasmus and kwashiorkor. The accelerated rate of protein turnover in children with marasmus and acute infection requires further investigation.