Effects of Hyperthyroidism on Amount and Activity of Brown Adipose Tissue

Identification and Regulation of Brown Adipose Tissue (BAT) in Humans. Implications for Energy Expenditure in Humans and in the Treatment of Obesity and Related Metabolic Diseases

Status

UNKNOWN

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT02133040

Enrollment

Registered

2014-05-07

Start date

2014-05-31

Completion date

2020-05-10

Last updated

2018-09-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hyperthyroidism

Keywords

Brown Adipose Tissue

Brief summary

The investigators wish to evaluate the effect of thyroid hormones on brown adipose tissue in humans in an observational study on patients with thyrotoxicosis. In the investigators evaluation the investigators will use FDG-PET/CT, indirect calorimetry and fat biopsies in the acute phase of the disease and in the euthyroid phase after treatment. It is the investigators hypothesis that high levels of circulating T3 might affect amount and function of brown adipose tissue.

Detailed description

10 patients with thyreotoxicosis (T3 \> 3 nmol/L and suppressed TSH) will be investigated at diagnosis and after 3-6 months of euthyroidism induced by antithyroid treatment. The patients will all be over the age of 50 due to the radiation given by the scans (requested by the local Ethical Committee). All will be scanned for active BAT by the integrated FDG PET-CT before and after treatment.BAT is activated by means of crushed ice placed under the feet in individualized intervals during the scan procedure. Indirect calorimetry is done to determine the basal metabolic rate and subcutaneous fat biopsy to examine the effect on subcutaneous white fat and the possible browning effect.

Interventions

None listed

Study design

Observational model

CASE_ONLY

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

50 Years to No maximum

Healthy volunteers

Inclusion criteria

* men and women with hyperthyroidism (T3 \> 3 nmol/l) * \> 50 years old * women must be postmenopausal

Exclusion criteria

* thyrotoxic crises * severe concurrent sickness that will make it unsafe to postpone treatment, this includes severe kidney disease (creatinin over 160)- and heart disease (NYHA group 3 and 4). * diabetes * former and current treatment with interleukin-2 * Patients who are already treated with β-blockers * severe claustrophobia * BMI \> 30 kg/m2

Design outcomes

Primary

Measure	Time frame	Description
FDG-PET/CT-scanning	6 months	Changes in Brown adipose tissue FDG uptake

Secondary

Measure	Time frame	Description
Indirect Calorimetry	6 months	Changes in basal energy expenditure

Other

Measure	Time frame
Changes in adrenergic receptor status and UCP1, PGC1alpha, PRDM16 and Dio2 levels in subcutaneous fat depots	6 months

Countries

Denmark

Outcome results