Fatigue In Subclinical Hypothyroidism

Investigating the mechanisms of muscle fatigue and cognitive symptoms in subclinical hypothyroidism

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN70749570

Enrollment

Registered

2013-05-15

Start date

2010-01-07

Completion date

Unknown

Last updated

2019-03-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Subclinical hypothyroidism Nutritional, Metabolic, Endocrine Subclinical iodine-deficiency hypothyroidism

Interventions

All patients are treated with tablet thyroxine for 6 months, at a dose of 1.6 µg/Kg, titrated 6 - 8 weekly, to attain a TSH of 1 - 1.5 mU/L.

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Aged 18 to 65 years 2. Subjects with confirmed SCH thyroid stimulating hormone (TSH) between 4.1 and 10.0 for more than 3 months 3. Fatigue Impact Score greater than 40

Exclusion criteria

Exclusion criteria: 1. Subjects with previous thyroid disease or on thyroid hormone replacement, anti-thyroid drugs, oral contraceptive pill (OCP), hypotensive agents, aspirin, statins or angiotensin converting enzyme (ACE) inhibitors/angiotensin receptor blocker 2. Subjects with known diabetes mellitus/impaired glucose tolerance (IGT)/impaired fasting glucose (IFG) 3. Known renal failure or a serum creatinine greater than 120 µmol/l within the past 3 months 4. Previous participation in a clinical trial within the past month 5. Previous history of vascular/heart disease 6. Malignancy (any) 7. Active infections 8. Body mass index (BMI) greater than 35 9. Psychiatric disease 10. Drug abuse 11. Previous major head injuries/epilepsy 12. Pacemakers/cerebral aneurysm clips 13. Pregnancy

Design outcomes

Primary

Measure	Time frame
1. Brain magnetic resonance imaging (MRI) - regional cerebral blood flow and activation of specific regions of intererest during N-back testing at baseline and 6 months 2. Muscle MRI - during rest, exercise and recovery-muscle pH, pH recovery, phosphocreatinine and recovery, inorganic phosphate/adenosine tri-phosphate (ATP) ratio at baseline and 6 months 3. Cardiac MRI - phosphocreatinine/ATP ratio at rest at baseline and 6 months 4. Autonomic function tests at baseline and 6 months: 4.1. Active standing for 3 minutes 4.2. Valsalva's manoeuver 4.3. Tilt testing - 40 minutes 4.4. Heart rate variability (HRV) - time and frequency domain analysis during rest, during and recovery from above manoeuvers 5. Psychometric questionnaires at baseline and 6 months: 5.1. Wechsler Abbreviated Scale of Intelligence (WASI) 5.2. Wechsler Test of Adult Reading (WTAR) 5.3. The Controlled Oral Word Association Test 5.4. Wechsler Memory Scale-III abbreviated (WMS) 6. Fatigue Impact Symptom Score at baseline and 6 months 7. Thyroid Symptom Check List and quality of life questionnaires at baseline and 6 months	—

Measure

Time frame

1. Brain magnetic resonance imaging (MRI) - regional cerebral blood flow and activation of specific regions of intererest during N-back testing at baseline and 6 months 2. Muscle MRI - during rest, exercise and recovery-muscle pH, pH recovery, phosphocreatinine and recovery, inorganic phosphate/adenosine tri-phosphate (ATP) ratio at baseline and 6 months 3. Cardiac MRI - phosphocreatinine/ATP ratio at rest at baseline and 6 months 4. Autonomic function tests at baseline and 6 months: 4.1. Active standing for 3 minutes 4.2. Valsalva's manoeuver 4.3. Tilt testing - 40 minutes 4.4. Heart rate variability (HRV) - time and frequency domain analysis during rest, during and recovery from above manoeuvers 5. Psychometric questionnaires at baseline and 6 months: 5.1. Wechsler Abbreviated Scale of Intelligence (WASI) 5.2. Wechsler Test of Adult Reading (WTAR) 5.3. The Controlled Oral Word Association Test 5.4. Wechsler Memory Scale-III abbreviated (WMS) 6. Fatigue Impact Symptom Score at baseline and 6 months 7. Thyroid Symptom Check List and quality of life questionnaires at baseline and 6 months

—

Secondary

Measure	Time frame
No secondary outcome measures	—

Countries

United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026