The thyroid gland and thyroid hormones predominantly affect metabolism in our bodies (protein, fat, and carbohydrate metabolism). The thyroid hormones can also affect the way in which our body uses and processes other important hormones. Thus, our thyroid gland is an integral part of our total body system functions.
Many patients are concerned about their thyroid function most specifically when it comes to weight management, energy, bowel function, and an overall feeling of wellness. When an individual is told ‘there is nothing wrong with your thyroid’, it is disappointing as they may assume that low thyroid function is the root cause of their health concerns. Additionally, a person with a diagnosed low functioning thyroid may feel that their medications are not relieving their symptoms. In these cases, it is important to look at a detailed set of lab exams in conjunction with a comprehensive medical intake of individual symptoms.
Thyroid stimulating hormone (TSH) is the lab marker most commonly used to evaluate total thyroid function. TSH will indicate how much ‘stimulation’ the thyroid needs to release the two most active thyroid hormones, T3 and T4. Current medical standard dictates that a person has a thyroid function issue only if they fall outside the TSH range of 0.5–4.5.1 However, there are individuals, approximately 6-8% of the population,2 with a seemingly normal TSH lab range of 2.5-4.0 that are still symptomatic of a low functioning thyroid. In the case where the patient has symptoms of low thyroid function, yet ‘normal’ labs, we must run further lab tests to assess the potential for ‘subclinical hypothyroidism’.
To fully assess thyroid function, lab tests for specific thyroid function and active thyroid hormones are run including: Free T3, Free T4, Free Thyroxine Index (FTI) and Reverse T3 (rT3). Free T3 and Free T4 are markers for the level of active, unbound thyroid hormone available in the body. It is essential to run both values, as often the treatment for low thyroid is to supplement with T4 hormone and in many cases some amount of T3 hormone is necessary. FTI is an indirect measurement of active T4, which, is analyzed alongside Free T4 values, and rT3 is an additional marker of potentially active T3 in the peripheral tissues of the body.3 Correlating these lab results with the patient’s medical history and symptoms will indicate if subclinical hypothyroidism is an issue.
Treatment for subclinical hypothyroidism will most often include a compounded prescription for T4 and T3, specifically tailored to the patient. A prescription of armour or generic dessicated porcine thyroid can also be used, depending on the individual’s needs. In a patient with a current diagnosis of hypothyroidism who still feels symptomatic, the labs mentioned above and a prescription change to armour thyroid or added T3 may assist in relieving these symptoms.
To assess total thyroid health, and the potential for subclinical hypothyroidism, a complete lab panel and a comprehensive physical exam are required. Additionally we look at underlying factors affecting thyroid function such as stress, exercise, dietary irritants, and environmental exposure, to get a patient’s total health picture. Thyroid health should only be evaluated and treated by a qualified health practitioner.
Dr. Shannon Sinsheimer is a Naturopathic Doctor at Optimal Health Center in Palm Desert and can be reached at (760) 568-2598.
Sources: 1) Surks M, Goswami G, Daniels G. The Thyrotropin Reference Range Should Remain Changed. The Journal of Clinical Endocrinology & Metabolism. 2005; 5489-5496. 2) Hollowell JG, Staehling NW, Flanders WD, Hannon WH, Gunter EW, Spencer CA, Braverman LE. Serum. TSH, T(4), and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). The Journal of Clinical Endocrinology & Metabolism. 2002; 489-99. 3) Powell DW: Endocrinology & Naturopathic therapies. Bastry University, Bothell. WZ.2005