Thyroid Hormone Replacement for Subclinical Hypothyroidism

Summary

Subclinical hypothyroidism (SCH) is a common condition among older men and women. Although by definition SCH comprises biochemically mild thyroid hormone deficiency without overt symptoms, it is a possible contributor to multiple problems in older age. Thyroid hormone has effects on numerous physiological systems, including the vascular tree, heart, skeletal muscle and brain. Therefore, thyroxine substitution to overcome thyroid hormone deficiency has the potential to give multisystem benefits to older people with SCH.

Small studies have reported reduced atherosclerosis and improved heart function with thyroxine replacement, but no large clinical trials have been performed. Therefore the available evidence is limited, leading to major variations in guidelines and clinical practice, with uncertainty regarding the indications for screening and treatment. The investigators propose a multicentre randomised placebo controlled trial to assess the impact of thyroxine replacement in a minimum of 540 older adults (maximum 750) with persisting SCH (excluding those in whom it is a temporary phenomenon who are unlikely to benefit). The investigators will include older men and women with a wide age range and of varying health status. Outcomes include health related quality of life, muscle strength, executive cognitive function and cardiovascular events, with a minimum of 1 year of follow up. Blood and urine samples will be stored in a biobank, to allow future research on causes of ill health in older people with SCH.

The investigators have the support of patient advocacy groups and a consortium with the wide range of expertise and experience required to conduct large scale multicentre clinical trials. The proposal explores the multisystem and quality of life benefits to older people of a tailored approach to management of SCH.

This clinical trial should definitively clarify whether thyroxine treatment for SCH provides benefits that are relevant for patients. This trial will provide strong evidence with the potential to improve clinical practice, reduce health care costs and promote healthy ageing of older adults.

Conditions

• Subclinical Hypothyroidism

Interventions

DRUG

Levothyroxine

The intervention will start with Levothyroxine 50 µg daily (reduced to 25 µg in subjects \<50Kg body weight or if known coronary heart disease - previous myocardial infarction or symptoms of angina pectoris) versus matching placebo; at 3 months if the serum TSH level is \<0.4 mU/L dose will be reduced by 25 µg; TSH \>=0.4 and \<4.6 mU/L, no change to dose; TSH \>=4.6mUL, additional 25 µg. The process will be repeated at 12 months then annually. Mock titration will be performed in the placebo group. The maximum possible dose of Levothyroxine that will be prescribed is 150μg.

DRUG

Placebo

Sponsors & Collaborators

• University of Glasgow

  collaborator OTHER

• University College Cork

  collaborator OTHER

• University of Bern

  collaborator OTHER

• Leiden University Medical Center

  collaborator OTHER

• NHS Greater Glasgow and Clyde

  lead OTHER

Principal Investigators

• David J Stott, MBChB MD · University of Glasgow

• Jacobijn Gussekloo, MD · Leiden University Medical Center

• Nicolas Rodondi, MD · University of Bern

• Patricia Kearney, MD · University College Cork

• Rudi JG Westendorp, MD · University of Copenhagen

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2014-05-31

Primary Completion

2016-11-18

Completion

2016-11-18

Countries

• United Kingdom

Study Locations