Diurnal pattern of plasma insulin concentration in the human

Abstract

Insulin in human plasma was assayed by the radioimmunological procedure of Yalow and Berson (10). Plasma insulin levels in the course of the day were compared with those found during the night. In the subjects studied, a higher insulin concentration was observed during the night when there is no stimulation brought about by food ingestion than during the day when normal feeding occurred. The differences at midnight and at 8 A. M. were statistically significant. The variation of the plasma insulin levels suggests of the existence of a circadian rhythm of the plasma insulin content. © 1966 Springer-Verlag.