Alternative therapies for thyroid disease examined
QUEBEC CITY — As alternative therapies such as hormone extracts and dietary supplements become more popular, clinicians must be aware of what they are, the effects that they have and how best to address their use among patients, presenters said here.
Extracts, compounded therapy
One commonly used alternative treatment for thyroid disease is desiccated thyroid extract, which is derived from pig thyroid glands, according to Anne R. Cappola, MD, ScM, associate professor of medicine at the Perelman School of Medicine at the University of Pennsylvania. Although one manufacturer of thyroid extract declined to describe its manufacturing process to Cappola, another said another described a highly standardized process. However, the high concentrations and short half-life of T3 in these dessicated preparations is still a concern for clinicians. Further, there are no randomized, controlled trials comparing thyroid extract with levothyroxine, and there is an absence of scientific evidence documenting efficacy and an acceptable risk–benefit ratio, she said.
Anne R. Cappola
Nevertheless, many patients consider using these products because they view them as a “natural” alternative. By sharing data showing the ability of levothyroxine therapy to provide adequate T3 levels, however, clinicians can reassure their patients about its use over thyroid extract, according to Cappola.
“But in the back of our minds, we shouldn’t be complacent that we are doing everything we can,” Cappola said. “It is possible that there are other factors in a nonfunctioning thyroid that need to be replaced.”
Cappola also discussed the prospect of compounded thyroid hormone therapy. Potential advantages include the ability to customize strength, select a different dosage or form, combine active ingredients into one formulation and exclude ingredients to which patients are allergic. Even so, these customized products are not regulated by the FDA. Therefore, the question becomes whether a clinician can trust a particular pharmacy to properly prepare the treatment. Concerns about stability also exist, she said, with one study finding that a liquid preparation of levothyroxine at 25 mcg/L had less than 90% of its initial potency after 14 days.
Data on dietary supplements
In a review of different dietary supplements and nutraceuticals, Kenneth D. Burman, MD, chief of endocrinology at Washington Hospital Center and professor in the department of medicine at Georgetown University, Washington, D.C., addressed their potential role in treating thyroid disease.
Kenneth D. Burman
Ultimately, he said, studies fail to associate many dietary supplements and nutraceuticals with improved outcomes. Some agents, such as bugleweed, calcium, iron and bonemeal, may even have adverse effects because they interfere with thyroid hormone absorption. Several other popular supplements, including ashwagandha, also known as Indian ginseng, only have animal data available and lack appropriate evaluation.
A few agents, such as soy protein, may have clinical effects, according to Burman, although the potential for adverse events may outweigh the minimal benefits. For instance, one study linked soy protein to a threefold increased risk for developing overt hypothyroidism in patients who originally had subclinical disease.
Tiratricol (Triac), which is found in many supplements, can cause hyperthyroidism in animals and humans, he said, and there is a lack of evidence showing that euthyroid humans will benefit from its administration. In fact, it can inhibit pituitary secretion of thyroid-stimulating hormone and cause hyperthyroidism at higher doses.
On the other hand, selenium does have potential benefits, with a double blind randomized clinical trial associating the agent with improved quality of life and decreased progression of disease in patients with Graves’ orbitopathy. Burman also highlighted another study showing that selenium decreased the incidence of effects related to postpartum thyroiditis when administered during pregnancy, although more data are needed before making firm clinical recommendations about routine use.
“Is there a role for use of dietary supplements or nutraceuticals in clinical practice to 'enhance' thyroid function in a euthyroid individual? The answer is a resounding no,” Burman said. “The conclusion is that the majority of dietary supplements fail to meet a level of scientific substantiation deemed necessary to recommend use in clinical practice.
As suggested in the recent American Thyroid Association/American Association of Clinical Endocrinologists guidelines on hypothyoridism: “Physicians should specifically engage patients regarding all forms of nutraceuticals, specifically those marketed for thyroid support, and consider the possibility that any dietary supplement or nutraceutical could be adulterated with T4 or T3.”
Wilson’s temperature syndrome
David S. Cooper, MD, of the division of endocrinology and metabolism, and professor of medicine at The Johns Hopkins University School of Medicine, also stressed the importance of communication and knowing where patients are getting their information during his discussion of Wilson’s temperature syndrome — an alternative medical concept that is not recognized as a medical condition by mainstream medicine.
David S. Cooper
Essentially, Cooper said, supporters of Wilson’s temperature syndrome, also known as Wilson’s thyroid syndrome, describe it as a mix of various nonspecific symptoms that are attributed to low body temperature, defined as lower than 98.6° F and impaired conversion of T4 to T3 despite normal thyroid function tests. Recommended treatment, according to the Wilson’s syndrome website, is T3 compounded to incorporate a sustained-release agent until a person’s temperature returns to 98.6° F.
Cooper pointed out, however, that a paper published in JAMA in 1992 by Mackowiak et al showed that average oral temperature in 140 individuals was 98.2° F, and was 97.6° F in the morning, leading the researchers to suggest abandoning 98.6° F as the norm. Therefore, a person taking T3 based on a diagnosis of Wilson’s syndrome may be at risk for the adverse effects of having an unnatural amount of T3 in some organs. Excessive T3 treatment can affect the heart and skeleton, which can be serious and even life-threatening, he said.
Citing a commentary published in 2006 in Clinical Endocrinology, Cooper emphasized the need to stand firmly behind the science, but at the same time communicate with patients in an open manner to maintain a level of trust so the patient receives the best care possible. – by Melissa Foster
For more information:
Jonklaas J. Arthur Bauman clinical symposium: Non-LT4 replacement therapies: Answers to your patients’ questions. Presented at: the American Thyroid Association 82nd Annual Meeting; Sept. 19-23, 2012; Quebec City.
Disclosure: Burman, Cappola and Cooper report no relevant financial disclosures.