Table 1: Plasma amino acid levels of Global Arginine Bioavailability Ratio (GABR) calculation components in healthy controls and patients with early-stage Alzheimer’s disease.

Amino Acid Control Alzheimer Disease Significance Level
L-Arginine 82.73 ± 3.58 74.87 ± 4.34 n.s.
L-Citrulline 26.77 ± 2.21 61.30 ± 4.04 P<0.001
L-Ornithine 65.30 ± 5.55 90.06 ± 8.75 P<0.01
Values are expressed in nmol/mL as mean ± SEM (n=46).