Change in hexose distribution volume and fractional utilization of [18F]-2-deoxy-2-fluoro-D-glucose in brain during acute hypoglycemia in humans

• Published in: Diabetes (New York, N.Y.) Vol. 39; no. 2; pp. 175 - 180
• Main Authors: Shapiro, E. T., Cooper, M., Chen, C. T., Given, B. D., Polonsky, K. S.
• Format: Journal Article
• Language: English
• Published: American Diabetes Association 01-02-1990
• ISSN: 0012-1797; 1939-327X; 0012-1797
• DOI: 10.2337/diabetes.39.2.175

Change in hexose distribution volume and fractional utilization of [18F]-2-deoxy-2-fluoro-D-glucose in brain during acute
hypoglycemia in humans.
E T Shapiro ,
M Cooper ,
C T Chen ,
B D Given and
K S Polonsky
University of Chicago, Department of Medicine, Pritzer School of Medicine, Chicago, Illinois 60637.
Abstract
We used positron emission tomography (PET) to study the effects of mild hypoglycemia on cerebral glucose uptake and metabolism.
Nine healthy men were studied under basal saline-infusion conditions, and during euglycemic and hypoglycemic clamp studies.
Insulin was infused at the same rate (1 mU.kg-1.min-1) in both clamp studies. In euglycemic clamp studies, glucose was infused
at a rate sufficient to maintain the basal plasma glucose concentration, whereas in hypoglycemic clamp studies, the glucose
infusion rate was reduced to maintain the plasma glucose at 3.1 mM. Each study lasted 3 h and included a 30-min baseline period
and a subsequent 150-min period in which insulin or glucose was administered. Blood samples for measurement of insulin, glucose,
cortisol, growth hormone, and glucagon were obtained at 20- to 30-min intervals. A bolus injection of 5-10 mCi [18F]-2-deoxy-2-fluoro-D-glucose
(2-DFG) was administered 120 min after initiation of the study, and plasma radioactivity and dynamic PET scans were obtained
at frequent intervals for the remaining 40-60 min of the study. Cerebral regions of interest were defined, and concentrations
of radioactivity were calculated and used in the three-compartment model of 2-DFG distribution described by Sokoloff. Glucose
levels were similar during saline-infusion (4.9 +/- 0.1 mM) and euglycemic clamp (4.8 +/- 0.1 mM) studies, whereas the desired
degree of mild hypoglycemia was achieved during the hypoglycemic clamp study (3.1 +/- 0.1 mM, P less than 0.05). The insulin
level during saline infusion was 41 +/- 7 pM.