Relationship between plasma glucose and insulin concentration, glucose production, and glucose disposal in normal subjects and patients with non-insulin-dependent diabetes.

Abstract

The changes in hepatic glucose production (R.), tissue glucose disposal (Rd), and plasma glucose and insulin concentration that took place over a 16-h period from 10 to 2 p.m. were documented in 14 individuals; 8 with non-insulin-dependent diabetes mellitus (NIDDM) and 6 with normal glucose tolerance. Values for R. were higher than normal in patients with NIDDM at 10 p.m. (4.73±0.41 vs. 3.51±0.36 mg/kg per min P < 0.001), but fell at a much faster rate throughout the night than that seen in normal subjects. As a consequence, the difference between R. in normal individuals and patients with NIDDM progressively narrowed, and by 2 p.m, had ceased to exist (1.75±0.61 vs. 1.67±0.47 mg/kg per min, P = NS).Plasma glucose concentration also declined in patients with NIDDM over the same period of time, but they remained quite hyperglycemic, and the value of 245±27 mg/dl at 2 p.m. was about three times greater than in normal individuals. Plasma insulin concentrations also fell progressively from 10 to 2 p.m., and were similar in both groups throughout most of the 16-h study period. Thus, the progressive decline in R. in patients with NIDDM occurred despite concomitant falls in both plasma glucose and insulin concentration. Glucose disposal rates also fell progressively in both groups, but the magnitude of the fall was greater in patients with NIDDM. Consequently, Rd in patients with NIDDM was higher at 10 p.m. (3.97±0.48 vs. 3.25±0.13 mg/kg per min, P < 0.001) and lower the following day at 2 p.m. (1.64±0.21 vs. 1.97±0.35 mg/kg per min, P < 0.01). These results indicate that a greatly expanded pool size can exist in patients with NIDDM at a time when values for R. are identical to those in normal subjects studied under comparable conditions, which suggests that fasting hyperglycemia in NIDDM is not simply a function of an increase in R1. Introduction Hyperglycemia can only develop when the rate of entry of

Production and metabolic clearance of glucose under basal conditions in Type II (non-insulin-dependent) diabetes mellitus

“…Other laboratories have, however, failed to find significant correlations, at least when glycaemia was less than about 10 mmol/l [10±14]. The reason for this might be as stated above, that the correlation between R a and glucose concentrations dissipates with time [9] and notably as these concentrations stabilize. Here a true steady-state is approached, glucose is no longer related to R a in time nor to R a in the subject population.…”

“…The constancy of MCR as well as the fact that dC/ dt is also approximately constant over the range where C is decreasing, in turn leads to the linear relation between R a and C in equation (9). Since this relation exists for each diabetic patient, it might be expected that it would be reflected in a similar relation in the population.…”

“…It has been suggested that tracer disequilibrium is responsible for errors in estimates of R a [9,10] under nonsteady-state conditions. This implies a specific activity, or enrichment, a, which varies throughout the system.…”

Autonomic Patterns Preceding and Following Accelerated Idioventricular Rhythm in Acute Myocardial Infarction

“…enhanced phase 4 depolarization of surviving subendocardial Purkinje fibers) in the infarcted area as the underlying mechanism in the development of AIVR in AMI [4, 16, 17]. This contention is supported by observations that the idioventricular rate, possibly related to the slow inward current, can be depressed by vagal stimulation, verapamil, acetylcholine or by the anti-adrenergic effects of adenosine [17, 18, 19, 20]. Enhanced α-receptor responsiveness, regional sympathetic denervation resulting in supersensitivity to catecholamines, changes in intracellular calcium concentrations, and heterogeneous adrenergic-mediated triggered activity may be additional mechanisms to account for AIVR [21, 22].…”

Effect of cigarette smoking and of a transdermal nicotine delivery system on glucoregulation in type 2 diabetes mellitus

“…This line was used for the infusion of glucagon and cold (nonradioactive) glucose on Day 1, or insulin and glucose (both nonradioactive and radioactive, see below) on Day 2. On both days, between 9.00 h and 9.30 h, a variable infusion of cold glucose was initiated and maintained until 12.00 h to "clamp" the plasma glucose concentration at the 09.00 h value, thus preventing the spontaneous decrease in plasma glucose in patients with NIDDM during prolonged fasting [20]. This ensured an identical plasma glucose concentration at 12.00 h on each study period.…”