The Role of Glucocorticoids to Maintain Energy Homeostasis During Starvation (Gluco-Starve)

Study Overview
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Brief Summary
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In a randomized, cross-over study, 20 healthy volunteers will receive a block and replace therapy that mimics physiological GC rhythm (metyrapone plus hydrocortisone) or placebo. Participants will undergo two identical fasting periods with each treatment. With the block and replace therapy, fasting-induced GC peak will be suppressed. Metabolic and autonomic parameters will be compared to reveal whether GCs mediate the physiological adaptions to caloric restriction. Understanding acute effects of GCs upon caloric restriction is critical, since repetitive disruptions of GC secretion may become harmful in chronic conditions.

Detailed Description
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Obesity is one of the major causes of morbidity and mortality worldwide. Achieving long-term weight loss is challenging, as the body counteracts weight loss to preserve energy by increasing appetite and lowering energy expenditure. These physiological defense mechanisms are the main obstacle to successful weight reduction in obese people. Therefore, identifying the signals that defend body weight during caloric restriction is essential for developing new antiobesity drugs. Corticosteroids mediate the physiological defense to starvation in rodents. Whether cortisol has the same impact on humans is unknown. Therefore, we investigate whether cortisol regulates the physiological adaptions to caloric restriction in humans. The general objective of this project is to investigate whether cortisol mediates physiological adaptions to caloric restriction. The primary objective is to test whether cortisol mediates the increased appetite during caloric restriction. Secondary objectives are to test whether the cortisol response to caloric restriction affects satiation, satiety, energy expenditure, substrate utilization, blood pressure, weight, body composition, secretion of neuroendocrine hormones, lipids, glucose, ketone bodies, sympathetic nervous system activity, immune cells, and inflammatory markers. This is a double-blind, randomized, placebo-controlled crossover study. After screening, subjects will be randomized to two crossover 7-day study periods with a wash-out period of 28 days: A) Participants will receive hydrocortisone 19.9 mg/d subcutaneously via a pump in a pulsed fashion (eight times/day) and metyrapone capsules per os (starting with a dose of 500 mg/d on day 1 to 3000mg/d on day 5, and then will be kept constant until day 7). B) Participants will receive a placebo (0,9% NaCl solution) subcutaneously via a pump in a pulsed fashion and identical-looking placebo capsules per os with the same regimen as for metyrapone. During both study periods, participants will undergo two days of caloric restriction.

Official Title
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The Role of Glucocorticoids to Maintain Energy Homeostasis During Starvation

Conditions
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Glucocorticoid Effect

Intervention / Treatment
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* Drug: Metyrapone 250 mg Oral Tablets
* Drug: Hydrocortisone 19.9mg s.c., pulsatile with a flow rate of 10μl/s
* Drug: Placebo 250 mg Tablets
* Drug: Placebo (0,9% NaCl solution)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI 18.5 - 27 kg/m2 Weight stability for 6 months prior to the trial (+/- 2kg) Exclusion Criteria: Previous medical history for any chronic condition in the last three months, active disease or abnormal physical examination as verified by a qualified physician. Casual smoking (>6 cigarettes per day) Frequent, heavy alcohol consumption (>30g/day) Frequent, heavy caffeine consumption (>4 caffeinated drinks/day) Regular physical exercise (>4hrs per week) Shift workers Participation in an investigational drug trial within the past two months Intake of any drugs (prescribed, over the counter or recreational), within 48 hours of the study initiation Intake of any steroids (including topical or inhaler) six month prior to the study Known allergy to metyrapone or hydrocortisone Inability or unwillingness to provide informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Double-blind, randomized, placebo-controlled cross-over study
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Metyrapone And Hydrocortisone<br>During one of the study periods, subjects receive hydrocortisone 19.9 mg/d subcutaneously via a pump in a pulsed fashion (eight times/day) and metyrapone per os (starting with a dose of 500 mg/d, then the dose will be increased the next days until 3000mg/d is achieved). | Drug: Metyrapone 250 mg Oral Tablets<br>* During one phase of the study: Metyrapone (pills of 250mg) on empty stomach: Day 1 0-1-1, day 2 1-2-2, day 3 2-3-3 day 4 3-4-4 day 5 4-4-4 day 6 4-4-4 day 7 4-0-0<br>Drug: Hydrocortisone 19.9mg s.c., pulsatile with a flow rate of 10μl/s<br>* Hydrocortisone will be delivered subcutaneously via a pump in a pulsed fashion with a flow rate of 10μl/s from day 1 to day 7 in a total daily dose of 19.9mg<br>|
| Placebo Comparator: Placebo<br>During the other study period, subjects receive placebo (0,9% NaCl solution) 19.9 mg/d subcutaneously via a pump in a pulsed fashion and the same dose of placebo tablets p.o instead of metyrapone | Drug: Placebo 250 mg Tablets<br>* During another phase of the study: identical looking placebo pills starting Day 1 0-1-1, day 2 1-2-2, day 3 2-3-3 day 4 3-4-4 day 5 4-4-4 day 6 4-4-4 day 7 4-0-0<br>Drug: Placebo (0,9% NaCl solution)<br>* Placebo (0,9% NaCl solution) 19.9 mg/d subcutaneously via a pump in a pulsed fashion with a flow rate of 10μl/s from day 1 to day 7<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Satiation | Amount of food intake with ad libitum buffet | Two 7-day intervention periods | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Satiety | Appetite rating by visual analog scale, minimum value 0, maximum value 100 | Two 7-day intervention periods | 
| Food preference | Amount of fat/ protein/carbohydrates consumed during ad libitum buffet | Two 7-day intervention periods | 
| Energy expenditure | Basal metabolic rate, diet-induced thermogenesis | Two 7-day intervention periods | 
| Substrate utilization | Respiratory quotient | Two 7-day intervention periods | 
| Blood pressure | Blood pressure | Two 7-day intervention periods | 
| Weight | Body weight | Two 7-day intervention periods | 
| Body composition | measured with DEXA-Scans and body impedance analysis | Two 7-day intervention periods | 
| Neuroendocrine hormones | Leptin, thyroid hormones, insulin, c-peptide, growth hormone, IGF1, catecholamines, GLP-1, GIP, glucagon, PYY, CCK, ghrelin, GDF-15, cortisol total and free, ACTH, renin, aldosterone, pregnenolone, progesterone, 11-deoxycorticosterone, corticosterone, 18-hydroxycorticosterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol, oxytocin, FGF-21 | Two 7-day intervention periods | 
| Lipids | Total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides | Two 7-day intervention periods | 
| Glucose | measured via blood sample | Two 7-day intervention periods | 
| Insulin sensitivity | measured via blood sample | Two 7-day intervention periods | 
| Ketone bodies | measured via blood sample | Two 7-day intervention periods | 
| Sympathetic nervous system activity | measured via ECG: Heart rate, interbeat interval, high-frequency activity, low-frequency activity, root mean square of successive differences | Two 7-day intervention periods | 
| Immune cells | Peripheral blood mononuclear cells (PBMCs) | Two 7-day intervention periods | 
| Inflammatory markers | IL-6, IL-1RA, IL-8, CRP | Two 7-day intervention periods | 
| Motivation to eat | clicking speed computer test | Two 7-day intervention periods | 
| Pleasure from eating | Fonts rating test | Two 7-day intervention periods | 
| Measure of behavioural approach and behavioural inhibition system | Questionnaire | Two 7-day intervention periods | 
| Eating behaviour type | Questionnaire | Two 7-day intervention periods | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cortisol, glucocorticoids, starvation, caloric restriction, fasting