By Bernard S. Little
WRNMMC Command Communications

Navy Capt. (Dr.) Thanh Hoang, program director for the National Capital Consortium (NCC) Endocrinology Fellowship and on staff at Walter Reed, recently spoke at the American Thyroid Association Annual Meeting in Washington, D.C., discussing his noted research focused on changing the paradigm of hypothyroidism treatment.

January is Thyroid Awareness Month, observed to raise awareness about thyroid-related diseases and thyroid cancer. According to the Centers for Disease Control and Prevention (CDC), “Thyroid disease is common, especially among older people and women, and checking for thyroid disease involves an evaluation of the thyroid by an experienced doctor.”
Approximately 1 in 10 people suffer from a thyroid disorder, and at least 1 in 8 women will develop a thyroid disorder during her lifetime.

“The thyroid gland, located in the front of the neck just below the Adam’s apple, takes iodine from the diet and makes thyroid hormone. Thyroid hormone affects a person’s physical energy, temperature, weight and mood,” the CDC explains.

According to health care providers, thyroid disorders generally fall into two broad groups: abnormal growth (nodules) in the gland and abnormal function. Most thyroid problems can be detected and treated, Hoang explained.

Benign nodules in the thyroid are common and don’t usually cause serious health problems, according to providers. Abnormal cell growth causes the nodules, which can occasionally put pressure on the neck and cause trouble swallowing, breathing or speaking if they are too large. The thyroid usually functions normally even when nodules are present.

Thyroid cancers are much less common than benign nodules, but with treatment, the cure rate for thyroid cancer is more than 90 percent.
Functional disorders of the thyroid are usually related to the gland producing too little thyroid hormone (hypothyroidism), also referred to as underactive, or too much thyroid hormone (hyperthyroidism), also described as overactive.

Symptoms of hyperthyroidism include unexpected weight loss, rapid or irregular heartbeat, sweating, and irritability, although some people experience no symptoms. Treatments consist of antithyroid medications, radioactive iodine, and sometimes surgery.

Hypothyroidism, when the thyroid gland doesn’t produce enough hormone, disrupts such things as heart rate, body temperature, and metabolism. Symptoms include fatigue, weight gain, mood swings and lethargy. Treatment consists of thyroid hormone replacement.

Hoang’s research, “Desiccated Thyroid Extract compared with Levothyroxine in the Treatment of Hypothyroidism: A randomized, double-blind, cross-over study,” was one of the first land-mark publication in hypothyroidism treatment, the first randomized, double-blind crossover study.

Hypothyroidism requires lifelong treatment with thyroid hormone pills. Levothyroxine is the main thyroid hormone produced by the thyroid gland and the synthetic form is the most common form of thyroid hormone replacement therapy. But before the availability of the pure levothyroxine, desiccated animal thyroid extract was the only treatment for hypothyroidism.

Hoang’s study compared levothyroxine to desiccated thyroid extract in terms of thyroid blood tests, changes in weight, psychometric test results and patient preference. The study included 70 patients with hypothyroidism treated with either desiccated thyroid extractor levothyroxine for 12 weeks followed by a switch to the other option for another 16 weeks. The participants were “blinded” during both phases – they did not know the type of pill they received. After each treatment period patients were weighed, had blood tests, underwent psychometric testing and were asked which therapy they preferred.

Hoang and his fellow researchers reported that 49 percent of the patients preferred desiccated thyroid extract, 19 percent preferred levothyroxine and 23 percent had no preference. Hoang reported desiccated thyroid extract use was also associated with more weight loss. There was no difference in the psychometric testing or in any symptoms. Both types of thyroid hormone were able to normalize the abnormal thyroid blood tests.

“These results suggest that there may be a certain number of patients in who desiccated thyroid extract might be a reasonable treatment option.
Further research is needed on this topic to confirm which patients this might benefit the most from desiccated thyroid extract therapy,” Hoang and his fellow researchers shared.

Hoang’s shared his history and study results at the ATA annual meeting alongside Dr. Elizabeth McAninch, another scientist and endocrinologist who works at Stanford University School of Medicine.

“I spoke about the key events in my journey to a focus on hypothyroidism,” Hoang shared. “My interest in hypothyroidism research began with my endocrine fellowship in 2009 at Walter Reed National Military Medical Center (WRNMMC), which was the National Naval Medical Center (NNMC) at that time, under the mentorship of Dr. Mohamed Shakir, now a retired US Navy captain and endocrinologist.

Hoang graduated from Lake Erie College of Osteopathic Medicine (LECOM) with assistance from the Health Professions Scholarship Program offered by the U.S. Navy. He completed his internal medicine internship/residency at NNMC, and then his endocrinology fellowship at the WRNMMC.

“I’ve had a great opportunity to work, collaborate, and publish with internationally recognized scientists and endocrinologists,” Hoang added. In addition to WRNMMC, his affiliations include the Uniformed Services University of the Health Sciences, National Institutes of Health, and MedStar Washington Hospital Center – “robust programs with significant scholarly activities and military relevant research,” he added.