Constant infusion and bolus injection of stable-label tracer give reproducible and comparable fasting HGO.

We have investigated the reproducibility of fasting hepatic glucose output (HGO) estimates by use of isotope dilution methodology of stable-label tracers. Six normal subjects were studied on two occasions 1 wk apart. After an overnight fast, the subjects received a bolus injection of 7 mg/kg of [U-13C]glucose and, simultaneously, a primed constant infusion of 0.05 mg.kg-1.min-1 of [6,6(-2)H]glucose. The bolus injection provided one estimate of HGO (HGOBOL), and the constant infusion provided two estimates of HGO, namely, HGO at 2 h (HGOINF2) and HGO at 4 h (HGOINF4), both with the assumption of steady-state conditions. All estimates were similar in value; HGOBOL was highest, followed by HGOINF2 and HGOINF4 [2.30 +/- 0.11 (SE), 2.17 +/- 0.12, and 2.01 +/- 0.13 mg.kg-1.min-1]. The constant infusion gave highly reproducible results. In the case of HGOINF2, the within-subject coefficient of variation (CV) was only 3% compared with 5% of HGOINF4. The reproducibility of HGOBOL was comparable with the within-subject CV of 7%. We conclude that a constant infusion and a bolus injection of stable-label tracer give reproducible and comparable estimates of HGO.

[1]  R. Henry,et al.  In Vivo Deactivation of Proinsulin Action on Glucose Disposal and Hepatic Glucose Production in Normal Man , 1986, Diabetes.

[2]  Claudio Cobelli,et al.  A model of glucose kinetics and their control by insulin, compartmental and noncompartmental approaches , 1984 .

[3]  J. Clore,et al.  Evidence for Dual Control Mechanism Regulating Hepatic Glucose Output in Nondiabetic Men , 1991, Diabetes.

[4]  R. Bergman,et al.  Assessment of insulin sensitivity in vivo: a critical review. , 1989, Diabetes/metabolism reviews.

[5]  G. Reaven,et al.  Effect of time on measurement of hepatic glucose production. , 1988, The Journal of clinical endocrinology and metabolism.

[6]  C. Cobelli,et al.  Assessment of Insulin Action in NIDDM in the Presence of Dynamic Changes in Insulin and Glucose Concentration , 1994, Diabetes.

[7]  I. Campbell.  Incorporation and dilution values—Their calculation in mass spectrally assayed stable isotope labeling experiments , 1974 .

[8]  G. Brechtel,et al.  Effects of Fasting on Plasma Glucose and Prolonged Tracer Measurement of Hepatic Glucose Output in NIDDM , 1987, Diabetes.

[9]  D. Kipnis,et al.  In-vivo Measurement of Glucose and Alanine Metabolism with Stable Isotopic Tracers , 1977, Diabetes.

[10]  R. DeFronzo,et al.  Effects of insulin on peripheral and splanchnic glucose metabolism in noninsulin-dependent (type II) diabetes mellitus. , 1985, The Journal of clinical investigation.

[11]  C Cobelli,et al.  Assessment of insulin action and glucose effectiveness in diabetic and nondiabetic humans. , 1994, The Journal of clinical investigation.

[12]  R. Wolfe,et al.  The measurement of glucose turnover and oxidation using radioactive and stable isotopes. , 1983, The Journal of surgical research.