Different effects of growth hormone releasing peptide (GHRP-6) and GH-releasing hormone on GH release in endogenous and exogenous hypercortisolism

OBJECTIVE Chronic hypercortisolism is associated with decreased OH responsiveness to GHRH, GHRP-6 is a synthetic hexapeptide that releases GH in several species, including man, As GHRH and GHRP-6 apparently stimulate GH release by different mechanisms, we evaluated the ON responses to these peptides in patients with endogenous and exogenous glucocorticoid excess and also in control subjects.DESIGN Six patients with endogenous hypercortisolism, nine with exogenous glucocorticoid excess; and 10 normal controls were submitted to three tests, in random order, with GHRH (100 mu g), GHRP-6 (1 mu g/kg) or GHRP+GHRP-6, in the same doses, i.v., on separate days.MEASUREMENTS GH was measured by immunofluorometric assay, IGF-I was determined by radio immunoassay, Plasma glucose was measured by the glucose-oxidase technique.RESULTS Peak GH values (mean+/-SE; mu g/l) after GHRH were significantly blunted in endogenous (2.0 +/- 0.7) and exogenous (3.6 +/- 1.2) hypercortisolae mic patients compared to controls (24.9 +/- 5.1), the endogenous group had lower peak GH values after GHRP-6 alone (7.7 +/- 1.9) or together with GHRH (18.8 +/- 5.8) than those observed in controls (GHRP-6: 22.1 +/- 3.6; GHRH+GHRP-6: 77.4 +/- 15.0) and in exogenous hypercortisolism (27.4 +/- 6.2 and 78.1 +/- 19.9). There were no differences in the GH responses to GHRP-6 alone or in combination with GHRH when controls were compared to the exogenous group, No changes in plasma IGF-I and glucose levels were observed.CONCLUSIONS Our results suggest that hypercortisolism had a different effect on the ON-releasing mechanisms stimulated by GHRH and GHRP-6. Moreover, in endogenous hypercortisolism both GHRN and GHRP-6 pathways are affected, while in the exogenous group GHRP-6 releasing mechanisms are apparently preserved.Universidade Federal de São Paulo, EPM, UNIFESP, DIV ENDOCRINOL, C POSTAL 20266, BR-04034970 São Paulo, BRAZILUniversidade Federal de São Paulo, EPM, UNIFESP, DIV ENDOCRINOL, C POSTAL 20266, BR-04034970 São Paulo, BRAZILWeb of Scienc

An exploration of pre-operative fasting practices in adult patients having elective surgery

Background: Patients fast routinely before elective surgery in order to reduce gastric volume and acidity. The standard fasting time is ‘nil by mouth’ from midnight before surgery. In recent years, new guidelines have recommended that patients remain nil by mouth from clear fluids for 2 hours and from solids for 6 hours. This literature review explored preoperative fasting practices in adult patients from an international perspective. Methods: A literature search was undertaken of databases, including CINAHL Plus, PubMed, Medline, the Cochrane Central Register of Controlled Trials, Science Direct, Sage Journals and Embase. Results: Anaesthetists were found to possess greater knowledge of reduced preoperative fasting than other health professionals including nurses. Conclusion: Actual fasting time was found to be relatively longer than prescribed fasting times

Risk Factors for Hospital Readmission Following Noncardiac Surgery: International Cohort Study

Objective:. To determine timing and risk factors associated with readmission within 30 days of discharge following noncardiac surgery. Background:. Hospital readmission after noncardiac surgery is costly. Data on the drivers of readmission have largely been derived from single-center studies focused on a single surgical procedure with uncertainty regarding generalizability. Methods:. We undertook an international (28 centers, 14 countries) prospective cohort study of a representative sample of adults ≥45 years of age who underwent noncardiac surgery. Risk factors for readmission were assessed using Cox regression (ClinicalTrials.gov, NCT00512109). Results:. Of 36,657 eligible participants, 2744 (7.5%; 95% confidence interval [CI], 7.2–7.8) were readmitted within 30 days of discharge. Rates of readmission were highest in the first 7 days after discharge and declined over the follow-up period. Multivariable analyses demonstrated that 9 baseline characteristics (eg, cancer treatment in past 6 months; adjusted hazard ratio [HR], 1.44; 95% CI, 1.30–1.59), 5 baseline laboratory and physical measures (eg, estimated glomerular filtration rate or on dialysis; HR, 1.47; 95% CI, 1.24–1.75), 7 surgery types (eg, general surgery; HR, 1.86; 95% CI, 1.61–2.16), 5 index hospitalization events (eg, stroke; HR, 2.21; 95% CI, 1.24–3.94), and 3 other factors (eg, discharge to nursing home; HR, 1.61; 95% CI, 1.33–1.95) were associated with readmission. Conclusions:. Readmission following noncardiac surgery is common (1 in 13 patients). We identified perioperative risk factors associated with 30-day readmission that can help frontline clinicians identify which patients are at the highest risk of readmission and target them for preventive measures