Circulating obestatin levels and the ghrelin/obestatin ratio in obese women.
OBJECTIVE
We measured blood levels of obestatin, total ghrelin, and the ghrelin/obestatin ratio and their relationship with anthropometric and metabolic parameters, adiponectin and insulin resistance, in overweight/obese and normal-weight women.


METHODS
Outpatients Unit of Endocrinology of the S Orsola-Malpighi Hospital of Bologna, Italy.


METHODS
Fasting obestatin, ghrelin, adiponectin and lipid levels, fasting and glucose-stimulated oral glucose tolerance test insulin, and glucose levels were measured in 20 overweight/obese and 12 controls. The fasting ghrelin/obestatin ratio was calculated; the homeostasis model assessment-IR (HOMA-IR) and insulin sensitivity index (ISI(composite)) were calculated as indices of insulin resistance.


RESULTS
Obese women had higher obestatin and lower ghrelin blood levels, and a lower ghrelin/obestatin ratio compared with controls. In all subjects, obestatin was significantly and positively correlated with total cholesterol and triglycerides, but not with ghrelin, anthropometric, and metabolic parameters. In the obese women, however, obestatin and ghrelin concentrations were positively correlated. By contrast, the ghrelin/obestatin ratio was significantly and negatively correlated with body mass index, waist, waist-to-hip ratio, fasting insulin, and HOMA-IR, and positively with ISI(composite) but not with adiponectin. None of these parameters were correlated with the ghrelin/obestatin ratio in the obese.


CONCLUSIONS
Increased obestatin, decreased ghrelin levels, and a decreased ghrelin/obestatin ratio characterize obesity in women. This supports the hypothesis that the imbalance of ghrelin and obestatin may have a role in the pathophysiology of obesity. On the other hand, some relevant differences between our data on circulating levels of obestatin and the ghrelin/obestatin ratio in obese subjects and those reported in the few studies published so far imply that further research is needed.
Vicennati
Valentina
V
Division of Endocrinology, Department of Internal Medicine, Centre for Applied Biomedical Research (CRBA), S Orsola-Malpighi Hospital, University Alma Mater Studiorum, Via Massarenti 9, 40138, Bologna, Italy.
Genghini
Silvia
S
De Iasio
Rosaria
R
Pasqui
Francesca
F
Pagotto
Uberto
U
Pasquali
Renato
R
D052242:Adiponectin / Q000097:blood; D000328:Adult; D000886:Anthropometry; D002784:Cholesterol / Q000097:blood; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000503:physiopathology*; D036361:Peptide Hormones / Q000097:blood*; D014280:Triglycerides / Q000097:blood
D052242:Adiponectin; D054439:Ghrelin; D036361:Peptide Hormones; D014280:Triglycerides; C505799:obestatin, human; D002784:Cholesterol