Do You Need Preventive Thyroid Treatment?

Treating Antibodies When TSH is Normal


Preventive thyroid treatment is a controversial subject, and many endocrinologists will simply dismiss you if you ask about it. But new research has been published that supports the understanding that autoimmune Hashimoto's disease may be preventable, slowed, or even stopped entirely before it progresses to destruction of the thyroid gland and hypothyroidism.

In a June 2005 presentation at the Endocrine Society's Endo 2005 conference, Dr. Ting Chang and colleagues reported on giving levothyroxine (i.e., Synthroid, Levoxyl, etc.) to euthyroid Hashimoto's thyroiditis patients -- patients who had normal range TSH (known as "euthyroid), but elevated antibodies.

Half the patients were given levothyroxine for six months and the other half not treated. Thyroid function tests and autoantibody titers were measured before and after the 6 month period. Those receiving levothyroxine had substantially decreased autoantibody levels; levels actually increased in some among the untreated group. TSH levels also decreased in the treated group, averaging 0.5 vs 2.5 in the untreated group. The researchers concluded that early prophylactic (preventative) levothyroxine treatment might be useful to help slow down the progression of the autoimmunity of Hashimoto's Thyroiditis.

This is not the first study to show that treatment can help.

In the March 2001 issue of the journal Thyroid, German researchers reported on their study of patients with euthyroid Hashimoto's, half of whom were treated with levothyroxine for a year, the other half untreated. After 1 year, the antibody levels and lymphocytes (evidence of inflammation) decreased significantly only in the group receiving the medication.

Among the untreated group, antibody levels rose or remained the same.

The researchers concluded that preventative treatment of euthyroid Hashimoto's patients reduced various markers of autoimmune thyroiditis, and speculated that such treatment might be able to stop the progress of Hashimoto's disease, or perhaps prevent development of hypothyroidism.

Just this year, Japanese researchers found that treatment with levothyroxine can reduce the incidence of Hashimoto's thyroiditis, as well as help alleviate the symptoms of the disease.

In the study of patients with euthyroid Hashimoto's disease, one group of patients received levothyroxine treatment, and the other group did not receive treatment. After 15 months, the treated group had significantly increased Free T4, significantly decreased TSH levels, and a reduction in both anti-thyroglobulin antibody (Tg-Ab) and anti-thyroid peroxidase antibody levels (TPO-Ab). The size of the thyroid also decreased in the treated group, while those not receiving treatment had an increase in thyroid size.

The researchers reported that although levothyroxine treatment is "mandatory in hypothyroid autoimmune thyroiditis patients, LT4 treatment which is shown to inhibit autoimmune process in animal models is still controversial in euthyroid Hashimoto's disease patients where disease has not destroyed the thyroid gland enough to cause hypothyroidism."

They found, however, that levothyroxine treatment at doses keeping TSH at low-normal levels appear to be effective not only in decreasing the autoantibody levels but also in the goiter size, which could ultimately prevent progression to overt autoimmune hypothyroidism.

What Do You Need to Know?

Some research shows, and practitioners have found​, that preventative treatment with levothyroxine may be warranted in people with euthyroid Hashimoto's disease (normal TSH levels, but thyroid auto-antibodies that show evidence of autoimmune Hashimoto's disease). Such treatment can in some cases slow down elevation of antibodies, and help prevent autoimmune disease and hypothyroidism.

If you have thyroid symptoms, a "normal" TSH level, but haven't been tested for thyroid auto-antibodies, insist on testing.

If you have thyroid symptoms, a "normal" TSH level, and elevated thyroid auto-antibodies, consider asking for treatment, and if your physician is unwilling, consider finding a more knowledgeable doctor.


En-Ting Chang, Du-An Wu, Dee Pei, Shi-Wen Kuo, Ming-Chen Hsieh. [P2-552] Influence of L-Thyroxine Administration in Patients with Euthyroid Hashimoto's Thyroiditis. Endocrine Society Endo 2005 Abstracts

Thyroid, 2001 Mar;11(3):249-55, "One-year prophylactic treatment of euthyroid Hashimoto's thyroiditis patients with levothyroxine: is there a benefit?"

Duygu Yazgan Aksoy, et. al. "Effects of Prophylactic Thyroid Hormone Replacement in Euthyroid Hashimoto's Thyroiditis" Endocr J (Japan) Vol. 52: 337-343, (2005).

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