TABLE 3

Correlation Between Rate Constants and Glucose Metabolism

	Glucose uptake		PR(¹¹CO₂)_T rate		PR(¹¹CO₂)_GLU rate
	mL/g/min						¹³C-GN (nmol/g)		¹³C-GN/MGU
Rate constant	R	P	R	P	R	P	R	P	R	P
K_1A (mL/g/min)	+0.71	<0.0001	+0.73	<0.0001			NS		−0.76	<0.0001
k_2A (min⁻¹)	NS		NS				NS		−0.59	<0.01
k_3A (min⁻¹)	+0.82	<0.0001	+0.82	<0.0001			NS		−0.83	<0.01
K_1B (min⁻¹)	−0.63	<0.001	−0.63	<0.001	−0.62	<0.001	NS		+0.71	<0.0001
k_2B (min⁻¹)	+0.68	<0.0005	+0.75	<0.0001	+0.72	<0.0001	NS		−0.71	<0.0005
k_3B (min⁻¹)	NS		NS		NS		NS		NS
k_4B (min⁻¹)	NS		NS		NS		NS		NS
K_5B (mL/g/min)	+0.66	<0.001	+0.49	<0.02	+0.52	NS	NS		−0.51	<0.03
k_6B (min⁻¹)	+0.71	<0.0001	+0.53	<0.01	+0.59	<0.005	−0.50	0.03	−0.67	<0.005
k_7B (min⁻¹)	+0.65	<0.001	+0.49	0.02	+0.56	<0.005	−0.55	0.02	−0.62	<0.05

K_1A–k_3A and k_1B–k_6B = estimated rate constants; R = correlation coefficient; PR(¹¹CO₂)_T rate = total fractional ¹¹CO₂ production × MBF; PR(¹¹CO₂)_GLU rate = fractional ¹¹CO₂ production from 1-¹¹C-glucose × MBF; ¹³C-GN = ¹³C-glycogen content 2 h after tracer injection; MGU = total glucose used during PET study (nmol/g); NS = not significant.