Growth Hormone, IGF-1 and Medical Treatment in Acromegaly: Are There Effects on Gut Hormone Physiology and Postprandial Substrate Metabolism?
- Conditions
- Acromegaly
- Registration Number
- NCT02152124
- Lead Sponsor
- University Hospital, Ghent
- Brief Summary
Acromegaly is a rare hormonal disorder leading to increased morbidity and mortality. In the vast majority of cases, a pituitary somatotroph cell adenoma causes excess growth hormone (GH) secretion, leading to hepatic insulin-like-growth factor 1 (IGF-1) hypersecretion. Both the disease as well as its treatment with long-acting somatostatin analogs (LA-SMSA) and/or pegvisomant affect glucose and lipid metabolism, possibly contributing to increased cardiovascular risk.
In this pilot study, the investigators want to explore insulin sensitivity, postprandial gut hormone response, lipid handling and adipocytokine profile in the following 4 groups:
* controlled acromegalic patients on LA-SMSA (group 1)
* controlled acromegalic patients on combination treatment of LA-SMSA and pegvisomant (group 2)
* acromegalic patients without need for medical therapy after surgery (group 3)
* healthy control subjects (group 4)
Furthermore, a longitudinal exploration will be performed in uncontrolled acromegalic patients (i.e. patients with serum IGF-1 levels above age-specific thresholds and/or symptoms due to active acromegaly (excessive sweating , arthralgia)) on LA-SMSA monotherapy (group 5). In this group, insulin sensitivity, postprandial gut hormone response, lipid handling and adipocytokine profile will be explored before introducing pegvisomant and three months after normalisation of IGF-1 levels.
The investigators hypothesize that lipid and glucose handling will be less efficient in the controlled acromegalic patients on LA-SMSA than in controlled patients on combination therapy or after surgery, and that there will be no difference in substrate metabolism between healthy controls and controlled acromegalic patients on combination treatment or after surgery. Further, they hypothesize that introducing pegvisomant in uncontrolled acromegalic patients will improve their postprandial lipid and glucose handling.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 21
- Diagnosis of acromegaly over 1 year ago, no changes in treatment schedule since at least 6 months (groups 1-3 and 5) OR healthy volunteer without diagnosis of acromegaly (group 4)
- Patient is willing to participate and has signed the informed consent
- Age > 18 years and < 80 years
- Body Mass Index 18-40 kg/m²
- Biochemistry: liver function tests > 3x ULN; HbA1C > 58 mmol/mol
- All untreated endocrine disorders including uncontrolled diabetes mellitus type 2 (i.e. HbA1C > 58 mmol/mol)
- Bariatric surgery; malabsorptive syndromes; hepatic or renal failure
- Current medication use: insulin, metformin, sulfonylurea, fibrates, incretin mimetics, dopamine agonists (for all but insulin, participation is allowed after a 2- week wash-out period)
- Abuse of alcohol or drugs
- Weight changes > 10% of body weight during preceding 12 months
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method change in insulin sensitivity before start of pegvisomant and 3 months after normalisation of IGF-1 after start of pegvisomant in group 5 Glucose disposal rate during last half hour of hyperinsulinemic-euglycemic clamp procedure, corrected for lean body mass (in µmol/min/kgLBM)
insulin sensitivity At enrollment in groups 1-4 Glucose disposal rate during last half hour of hyperinsulinemic-euglycemic clamp procedure, corrected for lean body mass (in µmol/min/kgLBM)
- Secondary Outcome Measures
Name Time Method change in fasting and postprandial glucose before start of pegvisomant and 3 months after normalisation of IGF-1 levels after start of pegvisomant in group 5 Serum glucose levels during mixed-meal test (before and 10, 30, 60, 120, 180, 240, 300 minutes after ingestion of standard mixed-meal (bread, margarine, cheese and milk) providing a caloric content of 1000 kCal whereby 45% of the energy comes from fat, 36% from carbohydrates and 19% from proteins)
fasting and postprandial glucose At enrollment in groups 1-4 Serum glucose levels during mixed-meal test (before and 10, 30, 60, 120, 180, 240, 300 minutes after ingestion of standard mixed-meal (bread, margarine, cheese and milk) providing a caloric content of 1000 kCal whereby 45% of the energy comes from fat, 36% from carbohydrates and 19% from proteins)
fasting and postprandial insulin At enrollment in groups 1-4 Insulin levels during standard mixed-meal test (cfr.supra)
fasting and postprandial gut hormone levels At enrollment in groups 1-4 Serum levels of gastric inhibitory polypeptide (GIP), ghrelin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1 (GLP-1), oxyntomodulin and cholecystokinin before start during standard mixed-meal test (cfr.supra)
fasting adipokine levels At enrollment in group 1-4 Fasting serum levels of leptin, adiponectin and interleukin 6 (IL-6)
fasting lipid levels At enrollment in groups 1-4 Fasting serum levels of triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol
change in fasting and postprandial gut hormone levels before start of pegvisomant and 3 months after normalisation of IGF-1 levels after start of pegvisomant in group 5 Serum levels of gastric inhibitory polypeptide (GIP), ghrelin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1 (GLP-1), oxyntomodulin and cholecystokinin before start during standard mixed-meal test (cfr.supra)
change in fasting adipokine levels before start of pegvisomant and 3 months after normalisation of IGF-1 levels after start of pegvisomant in group 5 Fasting serum levels of leptin, adiponectin and interleukin 6 (IL-6)
change in fasting and postprandial insulin levels before start of pegvisomant and 3 months after normalisation of IGF-1 levels after start of pegvisomant in group 5 Insulin levels during standard mixed-meal test (cfr.supra)
change in fasting lipid levels before start of pegvisomant and 3 months after normalisation of IGF-1 levels after start of pegvisomant in group 5 Fasting serum levels of triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol
Trial Locations
- Locations (1)
Ghent University Hospital, Department of Endocrinology, 9K12IE
🇧🇪Ghent, Belgium