Nutrition and somatomedin. XVII. Circulating somatomedin C during treatment of diabetic ketoacidosis.

Although somatomedin levels may be low in animals with experimental diabetes, values in humans have generally been normal. Because humans with severely decompensated diabetes have not been studied, we characterized somatomedin C responses during metabolic restoration in 21 patients with diabetic ketoacidosis. Somatomedin C values were compared with those of 25 outpatient controls. Somatomedin C in controls (mean +/- SE) was 0.72 +/- 0.09 U/ml, 69% of the mean sex-adjusted normal level; 28% of patients had values below the lower limit of normal. In ketoacidotic subjects, initial somatomedin C was 0.43 +/- .06 U/ml, 33% of the mean normal level; 52% of subjects had somatomedin C below the lower limit of normal. Initial levels in ketoacidotic subjects were unrelated to presenting levels of glucose, bicarbonate, ketones, or blood urea nitrogen but were significantly lower in patients of less than ideal body weight (0.30 vs. 0.58 U/ml, P less than .03). Presenting levels of somatomedin C in ketoacidotic subjects were significantly lower than in controls (P less than .02). During insulin-infusion therapy, somatomedin C rose to a peak of 1.16 +/- 0.21 U/ml after 28 h, significantly higher than initial levels (P less than .05). With continued subcutaneous insulin, somatomedin C fell to a nadir after an additional 22 h then rose more slowly to a final value of 0.75 +/- 0.12 U/ml, significantly higher than the nadir (P less than .05) but lower than peak values; final values in the ketoacidotic subjects were comparable to outpatient somatomedin C levels.(ABSTRACT TRUNCATED AT 250 WORDS)