Plasma levels of amino acids and hypermetabolism in patients with chronic obstructive pulmonary disease

Abstract Plasma levels of amino acids were measured by ion-exchange, high-pressure liquid chromatography in 30 ambulatory patients with chronic obstructive pulmonary disease (COPD; mean ± SD: age 64 ± 13 y and forced expiratory volume in 1 s [FEV 1 ] 0.85 ± 0.25 L) and 30 age- and sex-matched healthy control subjects with regard to nutritional status, resting energy expenditure (REE), and pulmonary function. The ratio of branched-chain amino acids to aromatic amino acids was significantly ( P r = 0.403, P r = 0.492, P 1 ( r = 0.467, P r = −0.716, P r = −0.770, P 1 ( r = −0.839, P r = −0.803, P