Metabolic Patterns during Physiologic

Sleep is a time of varying physiologic and metabolic activity (2, 3). Many of the metabolic patterns which occur during sleep have not been well characterized. One area which falls into this category concerns the changes in blood glucose that occur during sleep. Previous studies on normal subjects have given conflicting results. Hyperglycemia, normoglycemia, and hypoglycemia have been reported to characterize sleep. Endres and Lucke (4) studied a group of adults and concluded that blood sugar rose during sleep. Similar results were reported by Chieffi and Rosselli del Turco (5) in a study of a group of children. Trimble and Maddock (6) studied capillary blood glucose concentrations in a group of nine normal young medical students. Their studies included eight isolated values taken during sleep and a series of values on a single subject taken at hourly intervals during an entire night's sleep. They concluded, although their data were inadequate for final conclusions, that blood glucose seemed to remain essentially constant during sleep. Dienst and Winter (7) reported that sleep was consistently associated with hypoglycemia and indeed that hypoglycemia was capable of inducing sleep. To our knowledge, no systematic study of blood glucose concentrations during sleep has been undertaken in a sizable group of subjects with diabetes mellitus. Previous studies have had several limitations. Most workers have measured total blood-reducing substances rather than true glucose. The tech-