Stand the Test of Time

Let’s look at a brief and very condensed history of the thyroid gland. The earliest known record of any thyroid issues occurred in 2700 BC—in which an enlarged thyroid (goiter) was noted. Around 1600 BC, the Chinese started to use burnt seaweed and sponge for a goiter. In Indian medicine (Ayurveda) thyroid issues were described and called “galaganda”; the mainstay of treatment was a collection of herbs and balancing the “pitta dosha.” Around 1475 AD, Chinese scientist Wang Hei recommended that the treatment of thyroid issues should be ingestion of dried thyroid. In 1656, anatomist Thomas Wharton first penned the modern thyroid gland “glandula thyreoidea,” which is derived from the Greek word meaning “shield.” In 1811, Bernard Courtois discovered the element iodine, which proved to be very important to thyroid hormone synthesis. These early medical treatments are the basis of today’s treatment options.

Thyroid function

Many different conditions can affect the thyroid. We are going to focus on two of the major issues: primary hypothyroidism and primary hyperthyroidism. Remember, this is a very basic overview for further information; please discuss these with your primary care provider.

The thyroid gland is an organ that appears H-shaped or butterfly-shaped that has two lobes and is joined by a tissue called isthmus. The thyroid keeps your metabolism under control through the action of thyroid hormone, which it makes by extracting iodine from the blood. Thyroid cells are unique in that they are highly specialized to absorb and use iodine with the help of an amino acid called tyrosine. Every other cell depends on the thyroid to manage its metabolism. The two main hormones that the thyroid produces are T3 (triiodthyronine) and T4 (thyroxine). T3 is only around 20 percent of thyroid hormone produced, but it is the “stronger” of the two hormones. The thyroid gland works with the pituitary gland and hypothalamus to regulate T3 and T4 production. When T3 and T4 levels are low in the blood, the pituitary gland releases more TSH to tell the thyroid gland to produce more thyroid hormones. If T3 and T4 levels are high, the pituitary gland releases less TSH to the thyroid gland to slow production of these hormones.

Primary hypothyroidism

Primary hypothyroidism is defined by a high level of TSH and a low T4 concentration. The American Thyroid Association (ATA) and the American Association of Clinical Endocrinologists (AACE) recommend measurement of TSH in any individual at risk for hypothyroidism (e.g., personal history of type 1 diabetes or other autoimmune disease, family history of thyroid disease, history of neck radiation to the thyroid, history of thyroid surgery) and recommend consideration of measurement of TSH in patients over the age of 60 years.

Signs and symptoms of hypothyroidism include:

• Fatigue

• Weakness

• Weight gain or increased difficulty losing weight

• Coarse, dry hair

• Dry, rough, pale skin

• Hair loss

• Cold intolerance (you can’t tolerate cold temperatures like those around you)

• Muscle cramps and frequent muscle aches

• Constipation

• Depression

• Irritability

• Memory loss

• Abnormal menstrual cycles

• Decreased libido

Hypothyroidism in adults usually requires lifelong treatment. The goal of this treatment is to restore your body to a normal functioning thyroid (euthyroid) state. Treatments most commonly with levothyroxine (T4) and should ideally be taken on an empty stomach 60 minutes before a meal, preferably breakfast. Once treatment is initiated, your TSH level should be revaluated in six weeks, and changes made until levels are within normal range, which can vary from 0.45 to 4.5 milli-international units per liter (mIU/L). Many studies have shown better outcomes with this level closer to 2.

Primary hyperthyroidism

Around 20 times more women than men have hyperthyroidism. The diagnosis of hyperthyroidism is established by a raised serum total or free T4 or T3 hormone levels, reduced TSH level, and high radioiodine uptake in the thyroid gland along with features of thyrotoxicosis. A goiter may be present. Once the diagnosis of hyperthyroidism has been established, the cause of the hyperthyroidism should be determined, which is aided by additional lab tests such as thyrotropin receptor antibodies (TSI) and possible imaging of the head and/or neck.

Signs and symptoms of hyperthyroidism include:

• Fatigue or muscle weakness

• Hand tremors

• Eyelid lag/retraction

• Nervousness or anxiety

• Rapid heartbeat

• Heart palpitations or irregular heartbeat

• Skin dryness

• Trouble sleeping

• Weight loss

• Increased frequency of bowel movements

• Light periods or skipping periods Mainstay of treatment is with antithyroid drugs (thionamides) such as methimazole.

These drugs block the formation of thyroid hormone by the thyroid gland, therefore decreasing T3 and T4 levels. In most cases a beta blocker will also be prescribed to control the heart rate. Other treatment options include radioiodine or surgery. All three options may be used to treat the individual.

Always consult with your primary care provider or endocrinologist if you suspect you have an issue with your thyroid. The treatment needs to be tailored to each individual.

Graham Rachal, DNP, FNP-C is board-certified through the American Academy of Nurse Practitioners and completed his Doctorate of Nursing Practice through the University of South Alabama with a concentration and research emphasis in diabetes management. He is a member of Sigma Theta Tau, American Association of Nurse Practitioners and the Louisiana Association of Nurse Practitioners. He can be reached at (318) 798-4488, at his third-floor offices, 1455 East Bert Kouns Industrial Loop, Suite 300, Internal Medicine. For more information, visit the website http://www. highlandclinic.com/staff/graham-w-rachal-fnp.