title: Active ghrelin levels and active to total ghrelin ratio in cancer-induced cachexia.
abstract: Anorexia and weight loss are negative prognostic factors in patients with cancer. Although total ghrelin levels are increased in energy-negative states, levels of the biologically active octanoylated ghrelin and the anorexigenic peptide YY (PYY) have not been reported in patients with cancer-induced cachexia. We hypothesized that abnormal ghrelin and/or PYY levels contribute to cancer-induced cachexia. We evaluated 21 patients with cancer-induced cachexia; 24 cancer patients without cachexia; and 23 age-, sex-, race-, and BMI-matched subjects without cancer. Active ghrelin levels and the active to total ghrelin ratio were significantly increased in subjects with cancer-induced cachexia, compared with cancer and noncancer controls. PYY levels were similar among groups. Appetite measured by a visual analog scale was not increased in subjects with cachexia. The increase in active ghrelin levels is likely to be a compensatory response to weight loss. Cachexia may be a state of ghrelin resistance because appetite does not correlate with ghrelin levels. Changes in the active to total ghrelin ratio suggest that a mechanism other than increased secretion must be responsible for the increase in active ghrelin levels. PYY is unlikely to play an important role in cancer-induced cachexia.
authors.affiliation: Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism and The Huffington Center on Aging, Baylor College of Medicine, and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas 77030, USA. jgarcia1@bcm.tmc.edu
authors.forename: Josè M
authors.initials: JM
authors.lastname: Garcia
authors.forename: Mariana
authors.initials: M
authors.lastname: Garcia-Touza
authors.forename: Rabih A
authors.initials: RA
authors.lastname: Hijazi
authors.forename: George
authors.initials: G
authors.lastname: Taffet
authors.forename: Daniel
authors.initials: D
authors.lastname: Epner
authors.forename: Douglas
authors.initials: D
authors.lastname: Mann
authors.forename: Roy G
authors.initials: RG
authors.lastname: Smith
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Cunningham
authors.forename: Marco
authors.initials: M
authors.lastname: Marcelli
mesh_terms: D000368:Aged; D001066:Appetite; D002100:Cachexia / Q000097:blood* / Q000209:etiology; D054439:Ghrelin; D006801:Humans; D007333:Insulin Resistance; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D015850:Interleukin-6 / Q000097:blood; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000150:complications*; D036361:Peptide Hormones / Q000097:blood*; D019894:Peptide YY / Q000097:blood; D012709:Serum Albumin / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D054439:Ghrelin; D015850:Interleukin-6; D036361:Peptide Hormones; D012709:Serum Albumin; D014409:Tumor Necrosis Factor-alpha; D019894:Peptide YY; D007334:Insulin-Like Growth Factor I