"The project has the potential to significantly improve the health and well-being of older people with subclinical hypothyroidism"
- Professor David Stott from the University of Glasgow
TRUST Thyroid trial


The thyroid gland is located in the neck and controls how quickly the body uses energy and produces proteins; it also controls how sensitive the body is to various hormones.

What is subclinical hypothyroidism?

Subclinical hypothyroidism means that the thyroid gland, which is found in your neck, may not be producing the right amount of thyroid hormones that your body needs to do its job well. Thyroid hormones are important as they help regulate different parts of the body, including the circulation, heart, muscle and brain. A mildly underactive thyroid, a condition also known as subclinical hypothyroidism (SCH) affects around one in six people over the age of 65 and has been linked to various health problems, such as heart attacks and strokes, in later life. Subclinical means that there are no noticeable symptoms. Without a blood test, it is impossible to know that you have subclinical hypothyroidism.

What is the TRUST-project?

Right now, there is no common way to treat people with subclinical hypothyroidism. Researchers hope to find it with the TRUST study. TRUST researchers will follow 3,000 older people over a five year period in an attempt to better understand how to treat people who suffer from subclinical hypothyroidism. Half of the subjects will be treated with a hormone replacement drug, thyroxine, while the other half will be given a placebo; both groups will then be monitored to evaluate how they respond to the treatments.

Why have I been invited to take part?

We are inviting people over the age of 65 who have had a recent blood test at their doctors the results of which suggest that they may have subclinical hypothyroidism and therefore may be suitable to take part in the TRUST Study. We have asked your GP for permission to approach you about taking part in screening for the TRUST Study and they have agreed. However, it important to note that your GP has no other involvement with this study.

Do I have to take part?

You are not in any way obliged to take part - it is up to you to decide. If you do decide to take part you will be asked to sign a consent form for screening for the study. Even if you decide to take part you are still free to withdraw at any time and without giving a reason. This will not affect the standard of care you receive.

What will happen to me if I take part?

If you decide that you are interested in taking part in screening, you will be asked to sign a consent form. Then you would be invited to a screening visit at the Glasgow Clinical Research Facility, Western Infirmary at a time that suits you or at the Cork (Cork: please fill in). However, you may prefer to be assessed at home and this can be arranged with the study nurse. The screening visit would take place up to up to six weeks before the study starts and will last up to 30 minutes. The purpose of screening is to decide if you are eligible to take part in the TRUST study. To decide this, you would be asked some medical questions and a blood test would be taken. We would also collect some information from your medical record (paper-based and computerised, held by your GP or hospital; examples include information about your diagnoses, lab results, medical procedures, and medications). This is because we need to know if you have any problems with your health.

If the results from the screening tests and medical record examination are satisfactory you would be invited to take part in the TRUST study. The blood results from this visit will be available within 1 week. If these confirm that you are suitable to take part in the study you will be sent further details by post including a written invitation to take part in the treatment phase of the study. You will be informed in writing if you are not suitable for entry into the treatment phase of the study, with the reasons explained. If we find a medical condition of which you are unaware (e.g. high blood pressure), we will inform you, and write to your GP.

If you are suitable to take part in the full study, and decide to take part, the drug that will be tested is Levothyroxine, given as a capsule and taken by mouth. The purpose of the TRUST study is to determine whether there are benefits and drawbacks of giving Levothyroxine to older people with subclinical hypothyroidism.

We will follow up the long-term health outcomes of all people who are screened for entry into the TRUST trial, whether or not they enter the treatment phase of the study. We plan to do this by looking at routinely recorded health information held by the NHS and records maintained by the General Register Office in Scotland/ Fill in Cork. Your paper and computerised health records will be used by the University of Glasgow to follow up your future long-term health status. This will include paper and computerised records held by the NHS and electronic records maintained by the General Register Office at the Scottish Government.

If you are suitable to enter the full study, and decide to take part, the drug that will be tested is levo-thyroxine, given as a capsule orally (by mouth). We are testing whether it gives benefits to older people with a mildly underactive thyroid.

Will my expenses be paid?

Travel expenses will be provided to cover the cost of attending your visit.

Will my taking part in this study be kept confidential?

All information which is collected about you will be kept strictly confidential. We will keep your personal details on a secure computer at Glasgow University and the Clinical Research Facility. This is required to allow us to communicate with you (e.g. by post or telephone), and for us to link to the routine health information that is held by the Scottish Government.

However your name and contact details will not be disclosed to any other people, other than to your GP or hospital doctor who is providing care to you. Your GP and any hospital doctors who are caring for you will be notified of your screening for participation in the trial. Agreement from you that your GP can be informed is a condition of entering the study.

Any information which leaves your GP surgery or hospital will have your contact details, including name and address, removed so that you cannot be recognised from it. Your anonymised details and results will be shared with our collaborating investigators in the Netherlands, Ireland, Switzerland and the USA.

Who is organising and funding the research?

The organisation funding the research is the European Union. The team conducting the research in Scotland is from the University of Glasgow (linking with Greater Glasgow Health Board); this research is in collaboration with Leiden University Medical Centre in the Netherlands, Cork in Ireland, and University of Berne in Switzerland. We are also collaborating with thyroid experts from the University of California in the USA.

Contacts for Further Information

Further information can be obtained through the study freephone (number), or on the study website (www.address). General information about thyroid problems can be found on the Thyroid Federation International website at www.thyroid-fed.org.