Thermogenesis in Hyperthyroidism and Effect of Anti-Adrenergic Therapy

Study Overview
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Brief Summary
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The overall objective of the HEAT study is to determine the acute effect of propranolol on energy expenditure in patients suffering from hyperthyroidism and to evaluate the consequences of the change of hyper- to euthyroidism on metabolism during the course of treatment, especially with regard to the reaction to cold ambient temperatures.

Official Title
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Thermogenesis in Hyperthyroidism and Effect of Anti-Adrenergic Therapy

Conditions
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Hyperthyroidism

Intervention / Treatment
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* Drug: Propranolol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed Consent as documented by signature Age 18 to 70 years Hyperthyroidism: Thyroid-stimulating Hormone (TSH) below 0.2 mU and free T4 at or above 25 pmol/L or free T3 at or above 8 pmol/L. Exclusion Criteria: Contraindications to propranolol: hypersensitivity or allergy Therapy with a beta blocker for reasons other than hyperthyroidism (e.g. cardiac arrhythmia or heart failure) Treatment with amiodarone Women who are pregnant or breast feeding, Intention to become pregnant during the course of the study, History of asthma or chronic obstructive pulmonary disease Occlusive peripheral artery disease; Raynaud's syndrome. Other clinically significant concomitant disease states: Known renal failure (GFR < 50 ml/min) Known hepatic dysfunction known heart failure or unstable angina pectoris Known or suspected non-compliance, drug or alcohol abuse, Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant, Participation in another study with investigational drug within the 30 days preceding and during the present study, Previous enrolment into the current study, Enrolment of the investigator, his/her family members, employees and other dependent persons. ECG-criteria Resting heart rate below 60 bpm Complete left bundle branch block Atrioventricular block (AV-block) grade 2 or 3

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Propranolol 80 mg<br>Patients receive a single dose of 80 mg propranolol p.o. | Drug: Propranolol<br>* Patients receive a single dose of 80 mg propranolol p.o.<br>* Other names: beta blockade;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| acute effect of propranolol on energy expenditure in patients suffering from hyperthyroidism | difference in resting energy expenditure (REE) measured single 90 minutes after an oral dose of 80 mg of propranolol compared to resting energy expenditure measured during the thirty minutes prior to administration of propranolol (ΔREEPropranolol). | 90 minutes after propranolol application | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory quotient (RQ) before and after administration of propranolol. | Difference in respiratory quotient (RQ) before and after administration of propranolol. | 90 minutes after propranolol application | 
| Difference in skin temperature | Supraclavicular skin temperature in patients with hyperthyroidism after a single dose of 80 mg Propranolol compared to supraclavicular temperature before Propranolol. | 90 minutes after propranolol application | 
| Difference in REE from hyperthyroid to euthyroid state | indirect calorimetry to determine resting energy expenditure | after 3 to 4 months | 
| Difference in REE hyperthyroid state to euthyroid state | indirect calorimetry to determine resting energy expenditure | after 6 to 7 months | 
| Change in Body composition: percent body fat | dual xray absorption scan | after 3 to 4 months | 
| Cold induced thermogenesis (CIT) in patients with hyperthyroidism | Cold induced thermogenesis: Increase in energy expenditure above resting metabolic rate in response to a mild cold stimulus during hyperthyroidism as compared to euthyroidism. | after 3 to 4 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Brown adipose tissue (BAT), Hyperthyroidism