The decreased growth hormone response to growth hormone releasing hormone in obesity is associated to cardiometabolic risk factors.

The aim of the present study was to evaluate the relationship between GHRH-induced GH secretion in obese premenopausal women and cardiovascular risk markers or insulin resistance. Premenopausal obese women, aged 35-52 years, were studied. GH secretion, IGF-I, serum cardiovascular risk markers, insulin, leptin, mid-waist and hip circumference, total body fat, and truncal fat were measured. Subjects were classified as meeting the criteria for GH deficiency (GHD) when peak GH after stimulation with GHRH was

PYY(1-36) and PYY(3-36) secretory response after a mixed meal in healthy individuals.

BACKGROUND: Peptide YY (PYY) is a 36 amino acid peptide synthesized mostly by intestinal L cells. This peptide reaches its nadir during fasting and increases immediately after meals. After food intake, two molecular forms are released, PYY(1-36) and PYY(3-36). PYY(3-36) reduces food intake in both humans and rodents. There is scarce information about plasmatic concentrations of PYY, especially of PYY(3-36), after food ingestion, and their relationship to ghrelin. OBJECTIVES: To study PYY(1-36) and PYY(3-36) secretory response after a mixed meal, and its relationship to total and acylated ghrelin secretion in healthy subjects. SUBJECTS AND METHOD: We studied eight healthy subjects, 4 women and 4 men, with a median age of 53 (range, 36-59) years. After an overnight fast, the subjects received either a mixed standard meal (400ml Isosource Energy® [159kcal/100ml]) or placebo (400ml of water) orally in random order on two different days. Blood samples were obtained at 0, 30, 45, 60 and 120 min for measurement of PYY(1-36), PYY(3-36), total ghrelin and acylated ghrelin. Comparisons were made by Wilcoxon's test. Numerical correlations were performed using Spearman's test. P-values ≤ 0.05 were considered significant. RESULTS: After a mixed meal, PYY(1-36) reached a peak of (median [range]) 141.5 (81-198) pg/ml. There was no response to placebo, with a peak of 92.5 (46-219) pg/ml (p=0.04). The area under the curve (AUC) of PYY(1-36) levels after a mixed meal were 14,865 (8,032-19,822) pg/ml/min and after placebo were 8,992 (4,455-21,382) pg/ml/min (p=0.06). After ingestion of a mixed meal, PYY(3-36) reached a peak of 92.5 (59-135) pg/ml, with no response to placebo (46.5 [30-66] pg/ml) (p = 0.02). The AUC of PYY(3-36) levels after a mixed meal were 9,086 (6,412-14,970) pg/ml/min, and after placebo were 4,984 (3,142-6,772) pg/ml/min (p=0.012). The quotient between nadir total ghrelin/peak PYY(1-36) was markedly diminished after food ingestion, with preprandial values of 7.44 (3.64-14.56) and postprandial values of 3.55 (1.64-7.16) (p=0.03). The former quotient was unmodified by placebo. The quotient between nadir acylated ghrelin/peak PYY(3-36) was markedly diminished after ingestion of a mixed meal, with preprandial values of 2.03 (0.92-3) and postprandial values of 0.73 (0.26-1.27) (p=0.02). This quotient was unmodified by placebo. CONCLUSIONS: In healthy subjects, blood levels of both PYY(1-36) and PYY(3-36) increase after ingestion of a mixed meal. Simultaneously, total and acylated ghrelin levels diminish. The quotient between nadir acylated ghrelin/peak PYY(3-36) diminishes after a mixed meal. All these data suggest the possible contribution of these peptides to appetite regulation after ingestion.

Predictors of the metabolic syndrome and correlation with computed axial tomography.

OBJECTIVE: We investigated which anthropometric variables or imaging techniques, dual-energy x-ray absorptiometric densitometry (DXA) or bioelectric impedance analysis (BIA), are the most important determinants of the metabolic syndrome. We also evaluated the correlation between anthropometric parameters and DXA and computed axial tomography (CAT) in predicting visceral fat. METHODS: In a series of 399 overweight or obese patients (29.8% male and 70.2% female), anthropometric variables and imaging techniques (DXA or BIA) were measured and correlated with each component of the metabolic syndrome (diagnosed according to the criteria of the Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults of the National Cholesterol Education Program [Adult Treatment Panel III], with the exception of waist circumference). In a subpopulation of 109 patients, CAT was used to assess visceral fat and its correlation with the anthropometric variables and DXA. RESULTS: Applying receiver operating characteristic curves, the waist/height ratio was the best determinant of the metabolic syndrome (0.758, 95% confidence interval 0.634-0.882). The intra-abdominal diameter determined by DXA (r = 0.657, P < 0.001) and the waist/hip ratio (r = 0.603, P < 0.001) had the best correlation with visceral fat as measured by CAT. CONCLUSION: The prediction of visceral fat in overweight and obese patients, as assessed by anthropometric tests and DXA, offers a good alternative to CAT, without significant differences between them.

Altered fasting and postprandial plasma ghrelin levels in patients with liver failure are normalized after liver transplantation.

CONTEXT: Anorexia is a problem of paramount importance in patients with advanced liver failure. Ghrelin has important actions on feeding and weight homeostasis. Experimental data exist, which suggest that ghrelin could protect hepatic tissue. Both fasting and post-oral glucose tolerance test (OGTT) ghrelin concentrations are controversial in liver cirrhosis and are unknown after liver transplantation. OBJECTIVE: Our aim was to study fasting ghrelin concentrations and their response to an OGTT in liver failure patients before and after liver transplantation. DESIGN AND METHODS: We included 21 patients with severe liver failure studied before (pretransplantation, PreT) and 6 months after liver transplantation (posttransplantation, PostT), and 10 age- and body mass index-matched healthy or overweight subjects as the control group (Cont). After an overnight fast, 75 g of oral glucose were administered; glucose, insulin, and ghrelin were obtained at baseline and at times 30, 60, 90, and 120 min. RESULTS: Fasting ghrelin (median and range, pg/ml) levels were lower in PreT: 539 (309-1262) than in Cont: 643 (523-2163), P=0.045. Fasting ghrelin levels increased after liver transplantation, 539 (309-1262) vs 910 (426-3305), for PreT and PostT respectively, P=0.001. The area under the curve (AUC) of ghrelin (pg/ml min) was lower in PreT: 63,900 (37,260-148,410) than in Cont: 76,560 (56,160-206,385), P=0.027. The AUC of ghrelin increased in PostT, 63,900 (37,260-148,410) vs 107,595 (59,535-357,465), for PreT and PostT respectively, P=0.001. Fasting levels and the AUC of ghrelin were similar in PosT and Cont. CONCLUSIONS: Decreased fasting and post-OGTT ghrelin levels in liver failure patients were normalized after liver transplantation.

Fasting and postprandial plasma ghrelin levels are decreased in patients with liver failure previous to liver transplantation.

UNLABELLED: Anorexia is a problem of paramount importance in patients with advanced liver failure. Ghrelin has important actions on feeding and weight homeostasis. Concentrations of ghrelin are controversial in liver cirrhosis. Our aim was to study fasting ghrelin and their response to an oral glucose tolerance test (OGTT) in liver failure patients and normal subjects. METHODS: We included 16 patients with severe liver failure prior to liver transplantation. As a control group we included 10 age- and BMI-matched healthy subjects. After an overnight fast, 75 g of oral glucose were administered; glucose, insulin, and ghrelin were obtained at baseline and at times 30, 60, 90, and 120 min, respectively. RESULTS: Fasting ghrelin (median and range) were statistically significantly lower for patients compared to the controls, 527 (377-971) pg/ml vs. 643 (523-2163) pg/ml, P = 0.045, for patients and controls, respectively. The area under the curve for total ghrelin post-OGTT were lower in end-stage liver failure patients than in the control group, 58815 (44730-87420) pg/ml min vs. 76560 (56160-206385) pg/ml min, for patients and controls, respectively, P = 0.027. CONCLUSIONS: Ghrelin levels are significantly decreased both fasting and post-OGTT in patients with liver failure candidates for transplantation. Decreased ghrelin levels could contribute to anorexia in patients with cirrhosis.