Twenty-four-hour cortisol profiles demonstrate exaggerated nocturnal rise in diabetic children.

Plasma cortisol was measured every 20 min for 24 h in 12 normal and 8 insulin-dependent, nonketotic, diabetic children treated with one daily injection of insulin. Plasma glucose was also measured every 20 min in the diabetic children. The diurnal pattern of cortisol secretion was identical. The mean 24-h plasma cortisol was similar in both groups, but significantly elevated in the diabetic children between 0200 and 0920 h. Peak cortisol levels were higher in the diabetic than in the normal children. No correlation was found between average plasma glucose and average plasma cortisol, or between the nocturnal change in plasma glucose and average nocturnal plasma cortisol in the diabetic subjects. These studies demonstrate an exaggeration of the normal nocturnal rise in plasma cortisol in diabetic children not related to the levels of plasma glucose.