The aim of this study is to identify whether we can improve laboratory diagnostics in patients with hypothyroidism receiving thyroid hormone supplementation. We will investigate whether, in addition to the current laboratory tests of TSH and fT4,…
ID
Source
Brief title
Condition
- Thyroid gland disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
fT3, fT3/fT4 ratio and fT4 and TSH concentrations.
Secondary outcome
- Laboratory tests: rT3, TT4, TT3, SHBG, acylcarnitine profile, tyrosine,
phenylalanine, serine and DIO1/2/3 polymorphisms
- Questionnaire: ThyPRO-39
Background summary
Hypothyroidism is a common disorder in the Netherlands. Patients with
hypothyroidism have a deficiency of thyroid hormones in blood and tissues and
are treated with thyroid hormone (T4 or levothyroxine). T4 is a prohormone that
is converted to T3, the active hormone, in the tissues. The effect of T4
treatment is monitored by measuring thyroid hormones in the blood (TSH and/or
fT4). TSH is produced by the pituitary based on the circulating thyroid hormone
concentrations and is seen as a good reflection of thyroid hormone status.
Despite TSH and fT4 concentrations within the reference intervals, a part of
the patients still experience discomfort. Moreover, fT4 does not appear to be
the most suitable parameter in all cases for measuring thyroid hormone status
in patients taking levothyroxine. However, a better alternative has not yet
been implemented. In a small group of patients, TSH measurement cannot be
relied upon because of the cause of hypothyroidism, and, therefore, fT4 is the
most important marker to assess thyroid hormone status.
Study objective
The aim of this study is to identify whether we can improve laboratory
diagnostics in patients with hypothyroidism receiving thyroid hormone
supplementation. We will investigate whether, in addition to the current
laboratory tests of TSH and fT4, other already available laboratory tests
provide better insight into the thyroid hormone status of the patient.
Alternatives could be fT3 and the derived fT3/fT4 ratio. If these measurements
better reflect patient well-being in relation to thyroid hormone status, this
will particularly benefit the follow-up of patients taking L-T4 in whom TSH
cannot be used to monitor thyroid hormone status (such as patients with central
hypothyroidism).
Study design
Cross-sectional study design
Study burden and risks
- Venous blood sampling. In healthy controls, we will draw 20 mL of blood. The
risks are negligible and are limited to the development of a hematoma due to
the venipuncture.
- Additional venous blood sampling. In the study, we will draw 20 mL of blood
in addition to regular blood draw due to clinical purposes. There are no risks
involved, since the blood is collected for clinical purposes and the additional
collection of 20mL of blood does not have any risks or consequences.
Furthermore, results that are measured extra cannot present deviant outcomes
that lead to further research.
- Completion of questionnaire (ThyPRO-39). In the study, participants complete
a one-time brief questionnaire about the impact of their thyroid disorder on
their daily lives. Participants may experience a small psychological burden
when completing the questionnaire if their thyroid disorder negatively affects
their lives. However, the questionnaire is completed only once and by using the
short version, participants are unlikely to experience any difficulties.
Meibergdreef 9
Amsterdam 1105 AZ
NL
Meibergdreef 9
Amsterdam 1105 AZ
NL
Listed location countries
Age
Inclusion criteria
Hypothyroid patients
- Ability to provide informed consent;
- Ability to speak and understand Dutch or English
- Intake of a stable dose of levothyroxine, meaning the dosage of levothyroxine
must not be changed during the appointment at the outpatient clinic
- Diagnosis of one of these forms of hypothyroidism
O Patients with primary hypothyroidism: euthyroid based on TSH according to
physician
O Patients with hypothyroidism after a total thyroidectomy due to thyroid
carcinoma (therefore athyroid): on target TSH according to physician (target
TSH depending on stage/severity of carcinoma)
O Patients using L-T4 due to therapy of Graves* disease: euthyroid based on TSH
according to physician (TSH cannot be suppressed, namely TSH within reference
interval of 0,5-5,0 mU/L)
O Patients with central hypothyroidism: euthyroid based on fT4 according to
physician (common is fT4 in the upper limit, reference interval is 12-22 pmol/L)
Healthy controls
- Ability to provide informed consent;
- Ability to speak and understand Dutch or English
- Consider themselves healthy
Exclusion criteria
Hypothyroid patients
- Not euthyroid according to physician
- Pregnant
- Patients using L-T4 due to the treatment of Graves* disease: if TSH is still
suppressed
- Any of the following medication
o Iodide
o Liothyronine (Cytomel)
o Oral anticonceptiva
o Active treatment of malignancy (except DTC)
Healthy controls
- Pregnancy
- Any of the following medication
o Thyroid medication (a.o. levothyroxine, thiamazol, PTU)
o Lithium
o Amiodarone
o Propranolol
o Iodide
o Glucocorticoids
o Oral contraceptives
o Heparin
o Growth hormone
o Active treatment of malignancy
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL81578.018.22 |