1. The ‘big’ insulin content of the serums from ten children with protein–energy malnutrition was estimated before, during and after 3–6 weeks of treatment. The values for immunoreactive insulin (IRI) after intravenous injections of glucose were almost normal, with one exception, although tolerance was impaired. In addition, total body potassium content (TBK) was measured for three of the children on each test day.
2. In nine of twenty-three estimations ‘big’ insulin content was slightly more than 20% of the total IRI. However, there was a wide fluctuation in the values and no change was noted after treatment.
3. The amount of ‘big’ insulin did not correlate with either the magnitude of insulin secretion, the insulin:glucose ratio or TBK. There was a barely significant negative correlation between ‘big’ insulin content and degree of glucose intolerance, with some individual exceptions.