Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
The thyroid gland is a small gland found in the neck that produces two hormones, thyroxine and triiodothyronine, to help regulate the body’s metabolism. Hypothyroidism is a medical condition where the thyroid gland doesn’t produce enough of these hormones, causing many of the body functions to slow down. Symptoms of the condition include feeling tired and cold, gaining weight, difficulty concentrating and feeling depressed. It is also linked to an increased risk of cardiovascular (for example, heart) disease and oxidative stress. Endothelial Progenitor Cells (EPC) are cells that help regenerate the inner lining (endothelial layer) of blood vessels. They represent a well know marker of cardiovascular risk. The lower the EPC count the higher is the cardiovascular risk. Recent studies have demonstrated that EPC count is reduced in patients suffering from subclinical (without symptoms) hypothyroidism, and that replacement hormone treatment with Levothyroxine is able to restore an EPC count at similar levels to normal. It can therefore be speculated that low EPC count may contribute to the increased cardiovascular risk seen in people with hypothyroidism. One of the aim of this study is to evaluate EPC count either in subclinical hypothyroidism, or in overt (with symptoms) hypothyroidism and see whether there is a link between hypothyroidism and low EPC count. Blood pressure, and blood glucose and lipid levels are also measured to assess patients’ metabolic profile. The other aim of the study is to test the hypothesis that treatment with Levothyroxine is able to restore a normal EPC count in people with hypothyroidism. As already mentioned, hypothyroidism is also a condition characterized by increased oxidative stress, and Selenium, a trace element that is involved in thyroid function and thyroid hormones metabolism, has been shown to have anti-oxidant activity. With this in mind, we also test the hypothesis that Selenium, thanks to its anti-oxidant activity, may have a role in hypothyroid EPC count.

Who can participate?
Adults with hypothyroidism.

What does the study involve?
Participants are randomly allocated into one of 4 groups. Those in group 1 are given Levothyroxine once a day. Hose in group 2 are given 83 mg of Selenium once a day. Those in group 3 are given 166 mg of Selenium once a day. Those in group 4 are given 249 mg of Selenium once a day. All participants have thyroid function tests and EPC count tests at the start of the study and 3 months later. Participants in group 1 have an additional thyroid function test 45 days after starting their treatment to adjust the dose of Levothyroxine if required.

What are the possible benefits and risks of participating?
Not provided at time of registration.

Where is the study run from?
V. Fazzi Hospital (Italy)

When is the study starting and how long is it expected to run for?
May 2015 to July 2015

Who is funding the study?
V. Fazzi Hospital (Italy)

Who is the main contact?
Dr Roberto Negro

Trial website

Contact information



Primary contact

Dr Roberto Negro


Contact details

Piazza F. Muratore

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Levothyroxine and selenium effect on endothelial progenitor cells count in hypothyroid subjects: an interventional single centre trial


Study hypothesis

To test the impact of levothyroxine or selenium in endothelial progenitor cells count in hypothyroid patients

Ethics approval

Not provided at time of registration

Study design

Interventional single-centre trial

Primary study design


Secondary study design

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Endothelial progenitor cells in hypothyroid patients


The study has four treatment arms:
1. First arm, hypothyroid patients received Levothyroxine (once a day)
2. Second arm hypothyroid patients received Selenium 83 mg (once a day)
3. Third arm hypothyroid patients received Selenium 166 mg (one a day)
4. Fourth arm hypothyroid patients received Selenium 249 mg (once a day)
Thyroid function test were checked 45 days after initiation treatment to adjust the dose of Levothyroxine. In all the four arms thyroid function test end Endothelial Progenitor Cell count are checked at baseline and three months later.

Intervention type



Not Applicable

Drug names

1. Levothyroxine
2. Selenium

Primary outcome measure

EPC count in hypothyroid patients before and three months after treatment

Secondary outcome measures

Anthropometric and biochemical measures before and after treatment

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Hypothyroid patients having TSH>4.5mIU/L and <20mIU/L

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Cardiovascular disease
2. Diabetes
3. Hypertension
4. Drugs interfering with EPC count

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

V. Fazzi Hospital

Sponsor information


V. Fazzi Hospital

Sponsor details

Piazza F. Muratore

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

V. Fazzi Hospital (Italy)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The aim is to be published in a peer reviewed endocrine journal.

Intention to publish date

Participant level data

Not expected to be available

Basic results (scientific)

Publication list

2016 results in (added 02/09/2020)

Publication citations

Additional files

Editorial Notes

02/09/2020: Publication reference and total final enrolment number added.