24-hour glucose profiles during continuous or oscillatory insulin infusion. Demonstration of the functional significance of ultradian insulin oscillations.

Abstract

Under basal and stimulated conditions, normal insulin secretion oscillates with periods in the ultradian 100-150-min range. To test the hypothesis that oscillatory insulin delivery is more efficient in reducing blood glucose levels than continuous administration, nine normal young men were each studied on two occasions during a 28-h period including a period of polygraphically recorded sleep. Endogenous insulin secretion was suppressed by somatostatin, a constant intravenous glucose infusion was administered, and exogenous insulin was infused either at a constant rate or in a sinusoidal pattern with a period of 120 min. The mean glucose level over the 28-h period was 0.72+0.31 mmol/liter lower when insulin was infused in an oscillatory pattern than when the rate of infusion was constant (P < 0.05). The greater hypoglycemic effect of oscillatory versus constant infusion was particularly marked during the daytime, with the difference averaging 1.04+0.38 mmol/liter (P < 0.03). Serum insulin levels tended to be lower during oscillatory than constant infusion, although the same amount of exogenous insulin was administered under both conditions. Ultradian insulin oscillations appear to promote more efficient glucose utilization. (J. Clin. Invest. 1995Invest. . 95:1464Invest. -1471

Mathematical investigation of diabetically impaired ultradian oscillations in the glucose–insulin regulation

“…This suggests that they may be crucial in the maintenance of normal glucose homoeostasis [36]. Therefore, we adopt the presence and the accurate tuning of ultradian rhythms as a criterion for healthy glucose regulation, and ask the following question:…”

Ultradian Oscillations of Insulin Secretion in Humans

“…In the postprandial state, their amplitude is maximal immediately after food ingestion and then decreases progressively (1). The higher hypoglycemic effect of intermittent insulin administration, as compared with constant administration at the same average rate (5,6), suggests that, like the rapid pulses, these ultradian oscillations may have a functional significance. On the other hand, alterations in the glucose and ISR patterns have been described in patients with type 2 diabetes (7,8), and the tight coupling between glucose and ISR pulses is altered even in conditions where glucose tolerance is only minimally impaired (9).…”

Review Study of Detection of Diabetes Models through Delay Differential Equations

“…Due to the complex chemical reactions of the β cells, it takes a few minutes (5 -15 mins) for the insulin being ready to help cells utilizing glucose after the plasma glucose concentration level is elevate. As confirmed by, Sturis et al (1995) [9], Tolic (2000) [5], the effects of time delay are significant (Li et al, 2006) [6].…”