Biochemical tests in differential diagnosis of protein and calorie deficiencies.

Whitehead (1965) recently showed that a measurement of the amount of hydroxyproline excreted in the urine was of value in detecting marginal malnutrition. He also suggested that a simultaneous measurement of the plasma amino acid ratio (Whitehead, 1964) provided a biochemical means of differentiating between malnutrition, in which the primary deficiency was one of protein, and undernutrition due to deprivation of total calories. These tests were developed to be applied to children in nutritional surveys of communities, but it was considered that they might be of diagnostic value in the individual child who is more severely malnourished. In some children a clinical examination is sufficient to distinguish between the two syndromes, but in others the differential diagnosis is not so clear and more objective methods would be valuable, especially if the children are to be the subjects of metabolic studies. The first aim of this investigation was to evaluate the various biochemical tests which may be used to differentiate marasmus from kwashiorkor. The second aim was to use them to try to separate the two types of kwashiorkor seen in the wards of Kampala. In one, the typical clinical signs of kwashiorkor are found, and the hair is pale, silky, and sparse, while in the other the hair is less severely affected and the clinical picture is often complicated by some acute infection. Picou, Alleyne, Waterlow, and Seakins (1965) and Whitehead (1965) reported that the excretion of hydroxyproline peptides in the urine of children with kwashiorkor was greater at the end of treatment than at the beginning. This indicated that the urinary hydroxyproline index might also provide a useful means of assessing the response of malnourished and undernourished children to treatment. Material and Methods