Serum vitamin B12 concentrations in kwashiorkor and marasmus

One-carbon metabolism in children with marasmus and kwashiorkor

BACKGROUND

Kwashiorkor is a childhood syndrome of edematous malnutrition. Its precise nutritional precipitants remain uncertain despite nine decades of study. Remarkably, kwashiorkor's disturbances resemble the effects of experimental diets that are deficient in one-carbon nutrients. This similarity suggests that kwashiorkor may represent a nutritionally mediated syndrome of acute one-carbon metabolism dysfunction. Here we report findings from a cross-sectional exploration of serum one-carbon metabolites in Malawian children.

METHODS

Blood was collected from children aged 12-60 months before nutritional rehabilitation: kwashiorkor (N = 94), marasmic-kwashiorkor (N = 43) marasmus (N = 118), moderate acute malnutrition (N = 56) and controls (N = 46). Serum concentrations of 16 one-carbon metabolites were quantified using LC/MS techniques, and then compared across participant groups.

FINDINGS

Twelve of 16 measured one-carbon metabolites differed significantly between participant groups. Measured outputs of one-carbon metabolism, asymmetric dimethylarginine (ADMA) and cysteine, were lower in marasmic-kwashiorkor (median µmol/L (± SD): 0·549 (± 0·217) P = 0·00045 & 90 (± 40) P < 0·0001, respectively) and kwashiorkor (0·557 (± 0·195) P < 0·0001 & 115 (± 50) P < 0·0001), relative to marasmus (0·698 (± 0·212) & 153 (± 42)). ADMA and cysteine were well correlated with methionine in both kwashiorkor and marasmic-kwashiorkor.

INTERPRETATION

Kwashiorkor and marasmic-kwashiorkor were distinguished by evidence of one-carbon metabolism dysfunction. Correlative observations suggest that methionine deficiency drives this dysfunction, which is implicated in the syndrome's pathogenesis. The hypothesis that kwashiorkor can be prevented by fortifying low quality diets with methionine, along with nutrients that support efficient methionine use, such as choline, requires further investigation.

FUNDING

The Hickey Family Foundation, the American College of Gastroenterology, the NICHD, and the USDA/ARS.

Serum ferritin and cobalamin in growth retarded fetuses

OBJECTIVE

To examine fetal and maternal serum cobalamin and ferritin concentrations in pregnancies complicated by fetal growth retardation.

SETTING

Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London.

DESIGN

Cross sectional study.

SUBJECTS

Fetal blood samples obtained by cordocentesis from 20 growth retarded fetuses at 26 to 36 weeks of gestation. Maternal venous blood was also collected and serum ferritin and cobalamin concentrations were measured by radio-immunoassay in the fetal and maternal samples.

RESULTS

In the growth retarded group, the mean fetal serum concentration of cobalamin was higher than the normal mean for gestation (t = 3.27, P < 0.01), and this increase was significantly associated with fetal acidaemia (r = -0.686, P < 0.001) and erythroblastosis (r = 0.731, P < 0.001). In contrast, the fetal to maternal ferritin ratio was significantly reduced; there was a nonsignificant decrease in fetal serum and an increase in maternal serum ferritin concentration. There was an association between fetal serum ferritin concentration and erythrocyte count (r = -0.612, P < 0.01).

CONCLUSIONS

In placental insufficiency, as in postnatal starvation and Kwashiorkor syndrome, uptake and storage of cobalamin by the fetal liver may be impaired. The decrease in fetal to maternal ratio of ferritin could be the consequence of impaired placental perfusion.

Serum and red cell folates, and serum vitamin B 12 in protein calorie malnutrition

In 22 cases of kwashiorkor, 19 cases of marasmus, and 16 normal controls, red cell folate, serum folate, and serum vitamin B₁₂ were estimated, and the bone marrow and peripheral blood examined. Erythrocyte folate deficiency was shown in 9 cases of kwashiorkor and 7 cases of marasmus. Serum folate deficiency was present in 14 cases of kwashiorkor and 7 cases of marasmus. Megaloblastosis was found in 45% of cases of kwashiorkor and 37% of cases of marasmus. Megaloblastosis and macrocytosis correlated more with erythrocyte than with serum folate deficiency. Serum vitamin B₁₂ levels in children with kwashiorkor or marasmus did not differ from those of normal controls. The role of folate deficiency in the pathogenesis of megaloblastosis in protein calorie malnutrition was confirmed.

Serum vitamin B12 and folic acid (P.G.A.) levels in hypoproteinaemia and marasmus in Indian children

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