Effect of Thyroid Hormone Replacement on Fatigability in Untreated Older Adults With Subclinical Hypothyroidism

Thyroid hormone is a key regulatory hormone for a range of physiological systems. An impaired function of the thyroid gland such as subclinical hypothyroidism (SCH) can affect quality of life. Older adults with subclinical hypothyroidism often report non-specific symptoms such as tiredness. In addition, muscle symptoms such as cramps, weakness and myalgia are more common in SCH than in healthy controls. At present, evidence is lacking about the benefits of thyroxine replacement in the elderly with SCH, as no large randomized clinical trials (RCT) on the full range of relevant clinical outcomes, including tiredness have been performed. Moreover, there is continued uncertainty about the long-term impact on health related quality of life of thyroxine treatment for SCH. The aim of the study is to examine, within a large RCT of elderly participants with subclinical hypothyroidism, the impact of thyroxine therapy on the association between subclinical thyroid disease (SCTD) and the level of physical and mental fatigue. The existing trial infrastructure (TRUST thyroid trial-Euresearch FP7; clinicaltrials.gov ID: NCT 01660126) will be utilized to collect information on the level of physical and mental fatigue by using the Pittsburgh Fatigability Scale at baseline and at 1 year from 220 participants with persistent subclinical hypothyroidism randomized to either thyroxine or placebo.

Background

Thyroid hormone is a key regulatory hormone for a range of physiological systems. An impaired function of the thyroid gland such as subclinical hypothyroidism (SCH) can affect quality of life. Older adults with subclinical hypothyroidism often report non-specific symptoms such as tiredness. In addition, muscle symptoms such as cramps, weakness and myalgia are more common in SCH than in healthy controls. At present, evidence is lacking about the benefits of thyroxine replacement in the elderly with SCH, as no large randomized clinical trials (RCT) on the full range of relevant clinical outcomes, including tiredness have been performed. Moreover, there is continued uncertainty about the long-term impact on health related quality of life of thyroxine treatment for SCH.

Objective

To examine, within a large RCT of elderly participants with subclinical hypothyroidism (the TRUST trial), the impact of thyroxine therapy on the association between subclinical thyroid disease (SCTD) and the level of physical and mental fatigue.

Methods

The existing trial infrastructure (TRUST thyroid trial-Euresearch FP7, clinicaltrials.gov ID: NCT 01660126) will be utilized to collect information on the level of physical and mental fatigue by using the Pittsburgh Fatigability Scale at baseline and at 1 year from 220 participants with persistent subclinical hypothyroidism randomized to either thyroxine or placebo.

Eligibility Criteria:
Inclusion Criteria:

* Community-dwelling patients aged \>= 65 years with subclinical hypothyroidism
* Written informed consent

Exclusion Criteria

* Subjects currently under Levothyroxine or antithyroid drugs (amiodarone, lithium)
* Recent thyroid surgery or radio-iodine (within 12 months)
* Grade IV NYHA heart failure
* Prior clinical diagnosis of dementia
* Recent hospitalization for major illness or elective surgery (within 4 weeks)
* Terminal illness
* Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption
* Subjects who are participating in ongoing RCTs of therapeutic interventions (including CTIMPs)
* Plan to move out of the region in which the trial is being conducted within the next 2 years (proposed minimum follow-up period)