From the Guidelines
Hashimoto thyroiditis should be treated with oral T4 monotherapy (levothyroxine sodium) as the principal treatment for hypothyroidism, with the goal of improving morbidity, mortality, and quality of life. The treatment approach for Hashimoto thyroiditis involves managing the resulting hypothyroidism, which is typically achieved through daily oral levothyroxine administration 1. The dosage is usually started at 1.6 mcg/kg body weight and adjusted based on thyroid function tests every 6-8 weeks until stable, then annually. It is crucial to take the medication on an empty stomach, 30-60 minutes before breakfast or 3-4 hours after dinner, to ensure proper absorption.
Key considerations in managing Hashimoto thyroiditis include:
- Regular monitoring of thyroid-stimulating hormone (TSH) levels to ensure proper dosing 1.
- Awareness that treatment is typically lifelong due to the progressive destruction of thyroid tissue caused by the condition.
- Recognition of common symptoms such as fatigue, weight gain, cold intolerance, constipation, dry skin, and depression, which can be managed with medication and, to some extent, diet and lifestyle changes.
- The importance of informing healthcare providers about all medications being taken, as some can interfere with levothyroxine absorption.
The optimal screening interval for thyroid dysfunction, including Hashimoto thyroiditis, is unknown 1, but the serum TSH test is the primary screening test, with follow-up testing of serum T4 levels in persons with persistently abnormal TSH levels to differentiate between subclinical and overt thyroid dysfunction 1. While detection and treatment of abnormal TSH levels in asymptomatic persons are common practices, evidence that this approach improves important health outcomes, such as cardiovascular- and cancer-related morbidity and mortality, as well as falls, fractures, functional status, and quality of life, is lacking 1.
From the Research
Hashimoto Thyroiditis Overview
- Hashimoto thyroiditis is a common autoimmune disorder that affects women 7-10 times more often than men 2
- It is characterized by thyroid infiltration by lymphocytes, potentiated by antibody-mediated autoimmune response through the antibodies against thyroid peroxidase (TPOAbs) 2
- The presence of TPOAbs is associated with a 2 to 4-fold increase in the risk of recurrent miscarriages and preterm birth in pregnant women 2
Diagnosis and Treatment
- Diagnosis requires a detailed medical history, sonography, and blood analysis of thyroid function and thyroid antibodies 3
- Treatment typically involves levothyroxine replacement therapy, with a dose based on the degree of preserved thyroid functionality and lean body mass 2
- The dose of levothyroxine (LT4) used for treatment usually ranges from 1.4 to 1.8 mcg/kg/day 2
- There is insufficient evidence to recommend for or against therapy with triiodothyronine (T3), apart from in pregnancy when only levothyroxine is indicated 2
Cognitive Functioning and Quality of Life
- Patients with Hashimoto thyroiditis on long-term levothyroxine replacement may experience persistent impairments in both cognitive functioning and general well-being 4
- Global cognitive function, conceptual tracking, verbal divergent thinking, and anxiety and depression scores were significantly worse in patients compared to controls 4
- Quality of life was also impaired in patients, with a significant negative correlation between antibodies (TPOAb, TgAb) and quality of life (total SF36 score) 4
Malabsorption and Treatment Options
- Malabsorption of levothyroxine is often seen in patients with Hashimoto's disease-related hypothyroidism and comorbid GI conditions, such as gastroparesis and SIBO 5
- Switching to levothyroxine sodium oral solution may result in sustained TSH control and resolution of symptoms in patients with malabsorption issues 5