Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03064542 |
| Other study ID # |
2015/00718 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
October 13, 2015 |
| Est. completion date |
May 19, 2023 |
Study information
| Verified date |
May 2023 |
| Source |
Clinical Nutrition Research Centre, Singapore |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
To determine how thyroid status regulates the relationship between brown adipose tissue (BAT)
volume/activity, white adipose tissue (WAT) partitioning and basal metabolic rate (BMR) in
hyperthyroid patients transitioning to euthyroidism via antithyroid drugs.
To compare euthyroid outcomes (BAT, WAT, BMR, body composition, body weight and insulin
resistance) achieved by hypothalamus-pituitary-thyroid (HPT) set point vs. normal ranges of
plasma free thyroxine 4 (FT4) and throxine stimulating hormone (TSH).
Description:
Study Visit 1 is meant to confirm if subject's hyperthyroidism is due to Graves' disease via
a blood test called TSH receptor autoantibody (TRAb). This is a standard test that the doctor
will routinely order as part of clinical practice to diagnose the cause of the subject's
hyperthyroidism and is not part of the research procedure. If this TRAb blood test has been
done before the subjects have been referred to the endocrinology clinic at TTSH, the doctors
will review that result and decide if a repeat test is needed. If subjects are confirmed by
blood tests to have Graves' disease type of hyperthyroidism, they are eligible to take part
in this study. However, approximately 2 teaspoons (~ 10 mL) of blood will be taken for
baseline thyroid function test just prior to the initiation of anti-thyroid drugs.
Pre-menopausal women will also undergo a urine pregnancy test to exclude pregnancy prior to
participation at study entry. Once subjects have consented to participate in this study, they
will receive standard antithyroid drug (ATD) therapy as indicated clinically which in current
practice will either be carbimazole (CMZ) or thiamazole (TMZ).The clinic endocrinologists at
TTSH will be in charge of deciding on the ATD dose required based on the latest FT4, FT3 and
TSH blood test results as per standard medical practice. . Subjects will then be scheduled
for Visit 2 for baseline research measurements while you are still hyperthyroid.
On Study Visit 2, subjects will be asked to come to the Clinical Nutrition Research Centre
(CNRC) at the Centre for Translational Medicine at the National University of Singapore in
the morning at 0830 h after an overnight fast of 8-10 hours. Subjects will undergo
anthropometry (ie. measures of body weight, height, waist and hip circumference),
non-invasive percentage fat estimation using bioelectrical impedence analysis (BIA) and body
composition evaluation using dual energy X-ray absorptiometry (DXA) which allows
quantification of fat, lean and bone mass. Subjects will then undergo metabolic rate
measurement in a whole body calorimeter coupled with infrared thermography using a thermal
camera mounted on a tripod stand (IRT) focusing on the neck and area above the collar bone in
a whole body room calorimeter for the next 45 minutes.
Subjects will then proceed to the Clinical Imaging Research Centre (CIRC) also located in the
same building at the basement where an intravenous indwelling cannula will be inserted into
an arm vein from which a fasting blood sample will be taken. At first, 30 mL of blood will be
taken (about 6 teaspoons) in which 10 mL will be tested for thyroid function while the other
10 mL will be tested for liver and kidney function and the remaining 10mL for fasting
glucose, insulin and lipids. An additional 20 mL blood (about 4 teaspoons) will be taken for
analysis of markers of fat metabolism and protein profiles reflective of brown fat activity.
A urine sample will also be collected. Subsequently, subjects will be given an intravenous
injection of a radioactive labeled glucose called 18-FDG through the intravenous cannula and
followed by PET and fat fraction MRI scanning for BAT and MRI-MRS of abdominal white fat for
the next 1 hour.
After that, subjects will then be required to go to the endocrinology clinic at TTSH for
control of their hyperthyroidism via ATD. This may take about 6 months to attain stable
thyroid hormones levels (FT4, FT3, TSH). Subjects will be followed up every 6-8 weeks as per
standard medical practice by theTTSH endocrinologist and have their ATD doses adjusted till
their thyroid function tests are stable'. When this happens, subjects will continue with the
remaining part of the research, which is Study Visit 3. With the exception an additional
urine pregnancy test, Study Visit 3 is exactly the same as Study Visit 2.
