{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T12:00:02Z","timestamp":1784116802791,"version":"3.55.0"},"reference-count":31,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[1998,9,1]],"date-time":"1998-09-01T00:00:00Z","timestamp":904608000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1998,9,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>In patients with chronic obstructive pulmonary disease (COPD), muscle wasting can occur independently of fat loss, suggesting disturbances in protein metabolism. In order to provide more insight in amino-acid (AA) metabolism in patients with stable COPD, we examined arterial plasma and anterior tibialis muscle AA levels, comparing 12 COPD patients with eight age-matched healthy control subjects. We also studied relationships between AA levels, the acute phase response as measured by lipopolysaccharide-binding protein (LBP), and resting energy expenditure (REE). In contrast to findings in acute diseases associated with muscle wasting, we found increased muscle glutamine (GLN) levels in our patient group (mean \u00b1 SEM = 10,782 \u00b1 770 versus 7,844 \u00b1 293 \u03bc mol\/kg wet weight, p &amp;lt; 0.01). Furthermore, muscle arginine, ornithine, and citrulline were significantly increased in the patient group, whereas glutamic acid was decreased. In plasma, the sum of all AA (SumAA) was decreased in the patient group (2,595 \u00b1 65 versus 2,894 \u00b1 66 \u03bc mol\/L, p &amp;lt; 0.01), largely because of decreased levels of alanine (254 \u00b1 10 versus 375 \u00b1 25 \u03bc mol\/L, p &amp;lt; 0.0001), GLN (580 \u00b1 17 versus 641 \u00b1 17 \u03bc mol\/L, p &amp;lt; 0.05), and glutamic acid (91 \u00b1 5 versus 130 \u00b1 10 \u03bc mol\/L, p &amp;lt; 0.01). LBP levels were increased in COPD patients as compared with controls (11.7 \u00b1 4.5 versus 8.6 \u00b1 1.0 mg\/L, p &amp;lt; 0.05), and showed a positive correlation with REE (r = 0.49, p = 0.03), a negative correlation with the SumAA in plasma (r = \u2212 0.76, p &amp;lt; 0.0001), and no correlation with muscle AA levels. In conclusion, various disturbances in plasma and muscle AA levels were found in COPD patients. A relationship between the observed decreased plasma AA levels and inflammation was suggested.<\/jats:p>","DOI":"10.1164\/ajrccm.158.3.9708097","type":"journal-article","created":{"date-parts":[[2013,4,4]],"date-time":"2013-04-04T13:45:28Z","timestamp":1365083128000},"page":"797-801","source":"Crossref","is-referenced-by-count":79,"title":["Plasma and Muscle Amino Acid Levels in Relation to Resting Energy Expenditure and Inflammation in Stable Chronic Obstructive Pulmonary Disease"],"prefix":"10.1093","volume":"158","author":[{"given":"ELLEN M.","family":"POUW","sequence":"first","affiliation":[{"name":"Departments of Pulmonology and Surgery, Maastricht University, Maastricht; and Asthmacentre Hornerheide, Horn, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"ANNEMIE M. W. J.","family":"SCHOLS","sequence":"additional","affiliation":[{"name":"Departments of Pulmonology and Surgery, Maastricht University, Maastricht; and Asthmacentre Hornerheide, Horn, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"NICOLAAS E. P.","family":"DEUTZ","sequence":"additional","affiliation":[{"name":"Departments of Pulmonology and Surgery, Maastricht University, Maastricht; and Asthmacentre Hornerheide, Horn, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"EMIEL F. M.","family":"WOUTERS","sequence":"additional","affiliation":[{"name":"Departments of Pulmonology and Surgery, Maastricht University, Maastricht; and Asthmacentre Hornerheide, Horn, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[1998,9,1]]},"reference":[{"key":"2026032709083777800_B1","doi-asserted-by":"crossref","first-page":"1435","DOI":"10.1164\/ajrccm\/139.6.1435","article-title":"Body weight in chronic obstructive pulmonary disease.","volume":"139","author":"Wilson","year":"1989","journal-title":"Am. Rev. Respir. Dis."},{"key":"2026032709083777800_B2","doi-asserted-by":"crossref","first-page":"1793","DOI":"10.1183\/09031936.94.07101793","article-title":"Nutritional depletion in relation to respiratory muscle function in out-patients with COPD.","volume":"7","author":"Engelen","year":"1994","journal-title":"Eur. Respir. J."},{"key":"2026032709083777800_B3","doi-asserted-by":"crossref","first-page":"2807","DOI":"10.1183\/09031936.97.10122807","article-title":"Peak exercise response in relation to tissue depletion in patients with chronic obstructive pulmonary disease.","volume":"10","author":"Baarends","year":"1997","journal-title":"Eur. Respir. J."},{"key":"2026032709083777800_B4","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1164\/ajrccm\/147.5.1151","article-title":"Prevalence and characteristics of nutritional depletion in patients with COPD eligible for pulmonary rehabilitation.","volume":"147","author":"Schols","year":"1993","journal-title":"Am. Rev. Respir. Dis."},{"key":"2026032709083777800_B5","doi-asserted-by":"crossref","first-page":"819","DOI":"10.1136\/thx.51.8.819","article-title":"Evidence for a relation between metabolic derangements and increased levels of inflammatory mediators in a subgroup of patients with chronic obstructive pulmonary disease.","volume":"51","author":"Schols","year":"1996","journal-title":"Thorax"},{"key":"2026032709083777800_B6","first-page":"225","article-title":"Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD) and asthma.","volume":"137","author":"American Thoracic Society","year":"1987","journal-title":"Am. Rev. Respir. Dis."},{"key":"2026032709083777800_B7","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1016\/0261-5614(94)90028-0","article-title":"Influence of storage conditions on normal plasma amino acid concentrations.","volume":"13","author":"van Eijk","year":"1994","journal-title":"Clin. Nutr."},{"key":"2026032709083777800_B8","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/0378-4347(93)80062-9","article-title":"Rapid routine determination of amino acids in plasma by high-performance liquid chromatography with a 2-3 \u03bcm Spherisorb ODS column.","volume":"620","author":"van Eijk","year":"1993","journal-title":"J. Chromatogr."},{"key":"2026032709083777800_B9","doi-asserted-by":"crossref","first-page":"1250","DOI":"10.1093\/infdis\/171.5.1250","article-title":"LPS toxicity regulating proteins in bacteraemia.","volume":"171","author":"Froon","year":"1995","journal-title":"J. Infect. Dis."},{"key":"2026032709083777800_B10","doi-asserted-by":"crossref","first-page":"1461","DOI":"10.1136\/jnnp.50.11.1461","article-title":"Conchotome and needle percutaneous biopsy of skeletal muscle.","volume":"50","author":"Dietrichson","year":"1987","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"2026032709083777800_B11","first-page":"7","article-title":"Standardized lung function testing.","volume":"19","author":"Quanjer","year":"1983","journal-title":"Bull. Eur. Physiopathol. Respir."},{"key":"2026032709083777800_B12"},{"key":"2026032709083777800_B13","doi-asserted-by":"crossref","first-page":"364","DOI":"10.1177\/0148607192016004364","article-title":"Measurement of resting energy expenditure in patients with chronic obstructive pulmonary disease in a clinical setting.","volume":"16","author":"Schols","year":"1992","journal-title":"J. Parent. Ent. Nutr."},{"key":"2026032709083777800_B14"},{"key":"2026032709083777800_B15","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1111\/j.1753-4887.1990.tb02967.x","article-title":"Is glutamine a conditionally essential amino acid?","volume":"48","author":"Lacey","year":"1990","journal-title":"Nutr. Rev."},{"key":"2026032709083777800_B16","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1097\/00000658-197512000-00001","article-title":"Influence of postoperative state on the intracellular free amino acids in human muscle tissue.","volume":"182","author":"Vinnars","year":"1975","journal-title":"Ann. Surg."},{"key":"2026032709083777800_B17","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1097\/00000658-198007000-00014","article-title":"Muscle and plasma amino acids following injury.","volume":"192","author":"Askanazi","year":"1980","journal-title":"Ann. Surg."},{"key":"2026032709083777800_B18","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/0261-5614(82)90004-8","article-title":"Metabolic disorders in severe abdominal sepsis: glutamine deficiency in skeletal muscle.","volume":"1","author":"Roth","year":"1982","journal-title":"Clin. Nutr."},{"key":"2026032709083777800_B19","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1079\/NRR19930008","article-title":"Essential and conditionally-essential nutrients in clinical nutrition.","volume":"6","author":"Grimble","year":"1993","journal-title":"Nutr. Res. Rev."},{"key":"2026032709083777800_B20"},{"key":"2026032709083777800_B21","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1042\/cs0750415","article-title":"Muscle wasting in emphysema.","volume":"75","author":"Morrison","year":"1988","journal-title":"Clin. Sci."},{"key":"2026032709083777800_B22","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1164\/ajrccm.157.2.9608064","article-title":"Elevated inosine monophosphate levels in resting muscle of patients with stable COPD.","volume":"157","author":"Pouw","year":"1998","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"2026032709083777800_B23"},{"key":"2026032709083777800_B24","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1097\/00000658-198901000-00009","article-title":"Plasma amino acid profiles in sepsis and stress.","volume":"1","author":"Vente","year":"1989","journal-title":"Ann. Surg."},{"key":"2026032709083777800_B25","doi-asserted-by":"crossref","first-page":"902","DOI":"10.1164\/ajrccm\/141.4_Pt_1.902","article-title":"The nutritional status in advanced emphysema associated with chronic bronchitis: a study of amino acid and catecholamine levels.","volume":"141","author":"Hofford","year":"1990","journal-title":"Am. Rev. Respir. Dis."},{"key":"2026032709083777800_B26","first-page":"546","article-title":"Plasma amino acid levels in patients with chronic obstructive pulmonary disease.","volume":"48","author":"Schols","year":"1993","journal-title":"Monaldi Arch. Chest Dis."},{"key":"2026032709083777800_B27","doi-asserted-by":"crossref","first-page":"8477","DOI":"10.1016\/S0021-9258(17)37218-6","article-title":"Lipopolysaccharide binding protein expression in primary human hepatocytes and HepG2 Hepatoma cells.","volume":"269","author":"Grube","year":"1994","journal-title":"J. Biol. Chem."},{"key":"2026032709083777800_B28","doi-asserted-by":"crossref","first-page":"1453","DOI":"10.1164\/ajrccm.150.5.7952575","article-title":"Tumor necrosis factor-alpha levels and weight loss in chronic obstructive pulmonary disease.","volume":"150","author":"Di Francia","year":"1994","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"2026032709083777800_B29","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1016\/0002-9610(91)91143-7","article-title":"Cytokines and glucocorticosteroids in the regulation of the \u201chepato-skeletal muscle axis\u201d in sepsis.","volume":"161","author":"Fischer","year":"1991","journal-title":"Am. J. Surg."},{"key":"2026032709083777800_B30","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1097\/00005373-199205000-00011","article-title":"Adaptive regulation in skeletal muscle glutamine metabolism in endotoxin-treated rats.","volume":"32","author":"Austgen","year":"1992","journal-title":"J. Trauma"},{"key":"2026032709083777800_B31","doi-asserted-by":"crossref","first-page":"835","DOI":"10.1042\/bj2120835","article-title":"Glutamine metabolism in lymphocytes of the rat.","volume":"212","author":"Ardawi","year":"1983","journal-title":"Biochem. J."}],"container-title":["American Journal of Respiratory and Critical Care Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ajrccm\/article-pdf\/158\/3\/797\/67454050\/ajrccm_158_3_797.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ajrccm\/article-pdf\/158\/3\/797\/67454050\/ajrccm_158_3_797.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T13:08:47Z","timestamp":1774616927000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ajrccm\/article\/158\/3\/797\/8532495"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,9,1]]},"references-count":31,"journal-issue":{"issue":"3","published-online":{"date-parts":[[1998,9,1]]},"published-print":{"date-parts":[[1998,9,1]]}},"URL":"https:\/\/doi.org\/10.1164\/ajrccm.158.3.9708097","relation":{},"ISSN":["1073-449X","1535-4970"],"issn-type":[{"value":"1073-449X","type":"print"},{"value":"1535-4970","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[1998,9]]},"published":{"date-parts":[[1998,9,1]]}}}