title: Plasma orexin-a levels in COPD patients with hypercapnic respiratory failure.
abstract: Orexins have previously been shown to promote wakefulness, regulate lipid metabolism and participate in energy homeostasis. The aim of the study was to determine the relationship between plasma orexin-A and body composition in COPD in-patients with hypercapnic respiratory failure. 40 patients with hypercapnic respiratory failure and 22 healthy individuals were enrolled prospectively in this study. Plasma orexin-A levels, BMI, SaO(2), PaCO(2) and PaO(2) were noted for all the patients. Plasma orexin-A levels were higher in the underweight (UW) group, normal weight (NW) group and overweight (OW) group of COPD patients as compared with UW, NW and OW group of the control group (P < .05). Plasma orexin-A in COPD patients were higher in the OW group than in the NW group and the UW group. Plasma orexin-A levels showed significant correlation with body mass index (BMI), independent of PaO(2) (r = 0.576; P < .05) and %fat (r = 0.367; P < .05); a negative correlation was noted between plasma orexin-A levels and PaO(2) (r = -0.738; P < .05) and SaO(2) (r = -0.616; P < .05). Our results suggest that orexin-A levels are high in COPD patients with hypercapnic respiratory failure, and vary according to BMI and body composition. Orexin-A may be associated with the severity of hypoxemia in COPD patients with hypercapnic respiratory failure.
authors.affiliation: Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University School of Medicine, Shanghai 200032, China.
authors.forename: Lin-Yun
authors.initials: LY
authors.lastname: Zhu
authors.forename: Hanssa
authors.initials: H
authors.lastname: Summah
authors.forename: Hong-Ni
authors.initials: HN
authors.lastname: Jiang
authors.forename: Jie-Ming
authors.initials: JM
authors.lastname: Qu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000150:complications / Q000378:metabolism*; D000860:Hypoxia / Q000150:complications / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D009479:Neuropeptides / Q000097:blood*; D000068797:Orexins; D050177:Overweight / Q000150:complications / Q000378:metabolism*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D012131:Respiratory Insufficiency / Q000150:complications / Q000378:metabolism*; D012720:Severity of Illness Index
chemical_list: C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins