What is Hashimoto's (Hashimoto's thyroiditis)?

From the Guidelines

Hashimoto's thyroiditis is an autoimmune disorder that requires lifelong management, primarily through thyroid hormone replacement therapy, with the standard treatment being levothyroxine (T4) and dosage adjusted based on TSH levels, aiming for a TSH between 0.5-2.5 mIU/L, as recommended by the USPSTF 1.

Key Points

• The most common cause of hypothyroidism in the United States is chronic autoimmune (Hashimoto) thyroiditis, with risk factors including female sex, advancing age, white race, type 1 diabetes, Down syndrome, family history of thyroid disease, goiter, previous hyperthyroidism, and external-beam radiation in the head and neck area 1.
• The serum TSH test is the primary screening test for thyroid dysfunction, with multiple tests done over a 3- to 6-month interval to confirm or rule out abnormal findings, and follow-up testing of serum T4 levels to differentiate between subclinical and overt thyroid dysfunction 1.
• Treatment is generally recommended for patients with a TSH level that is undetectable or less than 0.1 mIU/L, particularly those with overt Graves disease or nodular thyroid disease, while treatment is typically not recommended for patients with TSH levels between 0.1 and 0.45 mIU/L or when thyroiditis is the cause 1.

Implementation of Treatment

1. Take levothyroxine on an empty stomach, 30-60 minutes before breakfast.
2. Avoid taking it with calcium, iron supplements, or certain foods that can interfere with absorption.
3. Have TSH levels checked every 6-8 weeks initially, then annually once stabilized.
4. Monitor symptoms such as fatigue, weight changes, and cold sensitivity. Additionally, maintain a healthy lifestyle with a balanced diet, regular exercise, and stress management, and consider selenium supplementation (200 mcg daily) to support thyroid function, as discussed with a healthcare provider 1.

From the Research

Definition and Prevalence of Hashimoto's Thyroiditis

• Hashimoto's thyroiditis (HT) is a common autoimmune disorder that affects approximately 1 in 1000 people 2.
• It is characterized by the destruction of thyroid cells, leading to hypothyroidism, and is more prevalent in women than men, affecting them 7-10 times more often 3.

Clinical Presentation and Diagnosis

• The clinical presentation of HT can vary, including thyrotoxicosis, euthyroidism, and hypothyroidism 3.
• Diagnosis is typically made through thyroid function tests, such as thyroid-stimulating hormone (TSH) measurements, and the presence of thyroid peroxidase antibodies (TPOAbs) 3.
• Thyroid ultrasonography can also be useful in assessing the degree of thyroid inflammation and guiding treatment decisions 4.

Treatment and Management

• Treatment for HT typically involves thyroid hormone replacement therapy, such as levothyroxine (LT4), to manage hypothyroidism 3, 5.
• The dose of LT4 used for treatment is based on the degree of preserved thyroid functionality and lean body mass, and usually ranges from 1.4 to 1.8 mcg/kg/day 3.
• Photobiomodulation (PBM) has also been shown to be effective in increasing T3/T4 ratio and decreasing TPOAb levels and weekly dosages of LT4 replacement therapy 6.
• A Paleolithic diet (PD) may also be used as a nutritional therapeutic protocol in patients with HT who have complications reducing weight and alleviating gastrointestinal and neurological symptoms 2.

Complications and Associated Risks

• HT is associated with an increased risk of papillary thyroid cancer and thyroid lymphoma, as well as recurrent miscarriages and preterm birth in pregnant women 3.
• Patients with HT may also experience complications such as lipid metabolism disorders, kidney injury, and muscle damage, which can be reversed with LT4 replacement therapy 5.