Impact of Helicobacter pylori infection on ghrelin and various neuroendocrine hormones in plasma.
OBJECTIVE
Ghrelin, an endogenous ligand for growth hormone secretagogue receptor, influences appetite, energy balance, gastric motility and acid secretion. The stomach is the main source of circulating ghrelin. There are inconsistent reports on the influence of Helicobacter pylori (H pylori) infection on circulating ghrelin levels. We sought to elucidate the relationship between ghrelin and various peptides in plasma, with special reference to H pylori.


METHODS
Plasma ghrelin levels were measured by radioimmunoassay in 89 subjects who were referred for upper gastrointestinal endoscopy, consisting of 42 H pylori infected and 47 uninfected ones. Plasma gastrin, somatostatin, leptin, insulin-like growth hormone 1 (IGF-1) and chromogranin A concentrations were also measured. Twelve patients were treated with anti- H pylori regimen.


RESULTS
Ghrelin circulating levels were greatly decreased in H pylori-positive than negative individuals (194.2+/-90.2 fmol/mL and 250.4+/-84.1 respectively, P<0.05), but did not significantly alter following the cure of infection (176.5+/-79.5 vs 191.3+/-120.4). There was a significant negative correlation between circulating ghrelin and leptin levels, as well as body mass index, for the whole and uninfected population, but not in H pylori-infected patients. Plasma ghrelin concentrations correlated positively with IGF-1 in H pylori-negative group and negatively with chromogranin A in the infected group. There were no significant correlations among circulating levels of ghrelin, gastrin and somatostatin irrespective of H pylori status.


CONCLUSIONS
H pylori infection influences plasma ghrelin dynamics and its interaction with diverse bioactive peptides involved in energy balance, growth and neuroendocrine function.
Isomoto
Hajime
H
Second Department of Internal Medicine, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki, Japan. hajimei2002@yahoo.co.jp
Ueno
Hiroaki
H
Nishi
Yoshito
Y
Wen
Chun-Yang
CY
Nakazato
Masamitsu
M
Kohno
Shigeru
S
D000328:Adult; D000368:Aged; D004734:Energy Metabolism; D005260:Female; D005755:Gastrins / Q000097:blood; D054439:Ghrelin; D016481:Helicobacter Infections / Q000378:metabolism*; D016480:Helicobacter pylori; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009490:Neurosecretory Systems / Q000378:metabolism*; D036361:Peptide Hormones / Q000097:blood*
D005755:Gastrins; D054439:Ghrelin; D020738:Leptin; D036361:Peptide Hormones; D007334:Insulin-Like Growth Factor I