Relation of kwashiorkor in early childhood and intelligence at school age

Abstract

Measured intelligence at school age was compared in 37 previously severely malnourished children and their siblings. The malnourished children all had been hospitalized for kwashiorkor (severe infantile malnutrition with edema) when they were between 6 and 30 months of age. The siblings had never experienced a bout of severe malnutrition requiring hospitalization. The sibling controls were all within 3 years of age of the index cases. Full scale WISC IQ of the index cases was 68.5 and of the controls 81.5. Verbal and performance differences were of similar magnitude and in the same direction. All mean IQ, differences were significant at less than the 5% level of confidence. If an IQ score of below 70 is considered a customary cut-off point for the definition of mental retardation then twice as many of the previously malnourished children as their sibs functioned below this level; 18 malnourished, compared with 9 of the control subjects, had an IQ below 70. Moreover, of those with a low IQ, 10 of the index cases were below 60, contrasted with only 2 of the control subjects. At the other extreme of the distribution, in the conventionally normal range, the reverse picture obtains; 10 of the control subjects compared with 4 of the index cases had an IQ. of 90 or higher (Table III). The long term effect of severe malnutrition in infancy has been suggested but not unequivocally demonstrated in comparative studies of malnourished children with controls drawn from the general population. To demonstrate the relation more convincingly it is necessary that children who have experienced such severe malnutrition be compared with their own sibs raised in the same family environment but not experiencing the same severity of nutritional insult. If differences in intellectual outcome exist between sib groups at school age the source of these differences may be more clearly related to the antecedent episode of severe malnutrition and hospitalization. © 1971 International Pediatrics Research Foundation, Inc.