Table 1. Insulin, C-peptide, glucose, FFA, glucagon, cortisol, T3-free, T3-total, and urea concentration in serum were determined at examination days during basal and clamp conditions (t = 30 and t = 270, respectively).

	Basal Condition			Clamp Condition
	Control	Fasting	p-value	Control	Fasting	p-value
Insulin, pM	41.5±3.8	15.3±1.6	<0.001	269.0±17.5	274.5±8.7	0.74
C-peptide, pM	593±76	174±50	<0.001	426±63	276±54	<0.01
Glucose, mM	5.1±0.06	3.9±0.13	<0.001	4.9±0.19	4.6±0.07	0.29
FFA, mM	0.48±0.09	0.84±0.06	<0.01	0.27±0.03	0.72±0.09	<0.001
Glucagon, ng/L	46.4±7.2	134.5±20.1	<0.001	37.5±4.4	58.5±7.5	0.03
T3-free, pM	5.4±0.13	3.7±0.15	<0.001	5.2±0.08	3.4±0.14	<0.001
T3-total, nM	1.8±0.08	1.3±0.06	<0.001	1.7±0.05	1.1±0.05	<0.001
Cortisol, nM	456±65	503±55	0.14	369±50	414±34	0.46
Urea, mM	5.3±0.3	6.2±0.3	0.05	4.8±0.3	6.0±0.3	<0.01
Blood flow, ml/(100 ml*min)	2.26±42	3.45±44	0.008
Q(phe), umol/(kg*h)	41.56±1.14	41.08±1.51	1
Q(tyr), umol/(kg*h)	28.22±0.88	29.37±1.39	0.44
Q(phe to tyr), umol/(kg*h)	3.22±0.35	2.50±0.35	0.22
Q(urea), umol/(kg*h)	307±33	390±37	0.19

Forearm blood flow, phenylalanine, tyrosine, urea and phenylalanine hydroxylation to tyrosine fluxes was measured at t = 210–240. Measurements were performed after an overnight fast of 10 hours (control) and after a 72-hour-fast (fasting). Values are means ± SE.