Profiles of metabolic control in diabetic children-frequency of asymptomatic nocturnal hypoglycemia

Abstract

Twenty-four hr glucose and hormonal monitoring was conducted in 34 randomly selected children with insulin dependent diabetes. Asymptomatic nocturnal hypoglycemia was present in 18% (6/34). The nocturnal plasma glucose decline of 20-25 mg/dl/hr reached a mean nadir of 50 mg/dl. The mean rebound hyperglycemia of 300 mg/dl over the subsequent 6.4 hrs. was significantly greater than any glucose excursion in diabetic children with daytime, symptomatic hypoglycemia (n = 5) or in those with non-hypoglycemic profiles (n = 23). Coincident with the nocturnal decline, but preceding the glucose nadir, was a marked release of growth hormone which was significantly greater (p less than .05) than that observed in the other diabetic groups. This release of growth hormone, and the nocturnal hypoglycemia, were reflected in the ratio of awake/sleep mean concentrations of glucose and growth hormone. These data support the speculation that growth hormone release contribute to the hyperglycemic rebound observed. Mean 24 hr growth hormone concentrations varied considerably from patient to patient such that a generalization for growth hormone concentrations in insulin dependent diabetes cannot be made. Asymptomatic nocturnal hypoglycemia is a frequent complication of the therapy of insulin dependent diabetes. Subsequent hyperglycemic rebound (the "Somogyi Effect") is associated with exuberant counterregulatory release of growth hormone. The precise pathophysiological role of this growth hormone release is unclear.