Hypothyroidism Booklet

HYPOTHYROIDISM

BY HEART THROBS CASE STUDY 23.2 GROUP 3

CASE STUDY

HYPOTHYROIDISM | BY HEART THROBS | CASE STUDY 23.2 | GROUP 3

A 67-year-old woman is referred for treatment of hyperlipidemia. Her cholesterol and triglycerides are high, despite treatment with lipidlowering medication. She is noted to have hair loss (wearing a wig) and hoarseness to her voice. She complains of cold intolerance and fatigue.

DIAGNOSIS: SECONDARY HYPOTHYROIDISM Hypothyroidism is a condition associated with the underproduction of thyroid hormones such as Thyroxine (T3) and Triiodothyronine (T4) by the thyroid gland. In some cases, hypothyroidism is referred to as underactive thyroid (Brent et al 2016, Ferri 2016, & Garber et al 2012). Thus, this results in normal or high thyroid stimulating hormone (TSH). The hormones that the thyroid secretes are used to control the rates of many metabolic processes in the body as well as how the body uses energy. Thus this underproduction results in the slowing of many metabolic process and consequently bodily functions (NIH MedlinePlus, 2012).

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HYPOTHYROIDISM | BY HEART THROBS | Case Study 23.2 | Group 3

PRIMARY, SECONDARY, OR TERTIARY?

PRIMARY HYPOTHYROIDISM Primary hypothyroidism Autoimmune thyroiditis or Inflammation to the thyroid is caused by the body’s immune system attacking itself.

SECONDARY HYPOTHYROIDISM Secondary or central hypothyroidism is related to pituitary dysfunction (Bishop, Fody, & Schoeff, 2018). That cause hormonal imbalances by not releasing enough TSH

TERTIARY HYPOTHYROIDISM Tertiary hypothyroidism is very rare, so this is an unlikely diagnosis for this case study (Bishop, Fody, & Schoeff, 2018) This form of hypothyroidism is associated with disorders of the Hypothalamus. This occurs when the hypothalamus fails to secrete TRH (Demers & Spencer, 2003).

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HYPOTHYROIDISM | BY HEART THROBS | CASE STUDY 23.2 | GROUP 3

SIGNS AND SYMPTOMS Some common signs seen in patients with hypothyroidism are: delayed relaxation phase of deep tendon reflex testing, bradycardia (which is a condition in which the heart rate is slower than normal), diastolic hypertension, coarsened skin, yellowing of skin (carotenemia), periorbital edema, hinning of eyebrows/loss of lateral aspect of brows, slowed movements/speech, pleural/pericardial effusion and ascites Symptoms can vary from person to person but may include; these symptoms are associated with significantly low T4 levels. Some early symptoms include cold intolerance, depression constipation, weight gain, fatigue, paleness, joint and muscle pain, weakness and thin, brittle hair and fingernails. Late symptoms, if left untreated include mental retardation (in infants), slowed cognition or cognitive dysfunction, menorrhagia, growth failure (children), pubertal delay, dry skin, edema, hoarseness, dyspnea on exertion, thickening of the skin, puffy face, hands and feet, decreases sense of taste and smell, diastolic hypertension, pleural and pericardial effusions

Figure 1: Signs and Symptoms of Hypothyroidism (“Understanding Hypothyroidism�, 2018)

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HYPOTHYROIDISM | BY HEART THROBS | Case Study 23.2 | Group 3

Figure 2. Clinical Presentation, Tests, and Treatment for Patients Presenting Secondary Hypothyroidism.

This conditions is associated with low ACTH and adrenaline (epinephrine and norepinephrine) levels that may lead to hyperlipidemia since ACTH regulates cholesterol and lipid metabolism. Low GH, LH, and FSH levels may be documented in the presence of a pituitary adenoma. Some tests include blood baseline blood test for hypophyseal hormones (ACTH and TSH), thyroid hormone ( free/bound T4) and adrenal hormones (especially cortisol). Low serum levels of these hormones suggest secondary hypothyroidism.

Treatment is based on hormone replacement.

Information presented in the chart is a summary from all sources cited in red.

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HYPOTHYROIDISM | BY HEART THROBS | CASE STUDY 23.2 | GROUP 3

QUESTION 1. WHAT TESTING WOULD BE HELPFUL TO SCREEN FOR THYROID DISEASE? TSH TEST

used to check the level of thyroid-stimulating hormone (TSH) in the blood.

Your TSH level can indicate if your thyroid gland is working properly (Bishop, Fody, & Schoeff, 2018).

CREATINE KINASE LEVELS

FREE T4 TEST

Determines how the thyroid is functioning which is measured by radioimmunoassay (RIA), chemiluminometric assay, or similar immunometric technique.

FINE-NEEDLE ASPIRATION

Thyroid fine-needle aspiration (FNA) biopsy is most accurate screening in the evaluation of thyroid nodules in the absence of hyperthyroidism. The routine use of FNA allows prompt identification and treatment of thyroid malignancies and avoids unnecessary surgery in most individuals with benign thyroid lesions

NUCLEAR MEDICINE EVALUATION

An example is thyroid scintigraphy.

This methodology uses radioactive material to screen for diseases including analysis of structure and function (Chaudhary & Bano, 2013; NIDDK, 2017).

T3 TEST

Often useful for diagnosing hyperthyroidism or to determine the severity of the hyperthyroidism. Patients who have hyperthyroid will have an elevated T3 level.

Creatine kinase (CK) elevation is known to be related to poor thyroid function. By testing CK serum levels we can trace the cause of the elevated levels to be due to hypothyroidism. Treatment of hypothyroidism brings CK levels back to normal limits (Beyer et al., 1998).

THYROID ULTRASOUND

Usually performed after a fine needle aspiration biopsy. This tests uses sound waves in the form of ionizing radiation as a way of capturing the image of the desired organ or gland- ( thyroid)-typically looking for abnormalities such as unusual/ malignant nodules or lumps located in the neck

ANTITHYROID ANTIBODY TEST

Used to see if thyroid antibodies are formed in the patient’s blood (American Thyroid Association, 2018). This is usually used to help diagnose autoimmune thyroid disorders such as Hashimoto’s Disease or Graves’ Disease (hyperthyroidism)

MRI

to document the presence of a mass is also suggested as well as testing for alpha subunits, which are tumor markers (Loyola University, 2018).

MEDICATIONS

Check if the patient is currently taking any of these medications as they can cause hypothyroidism in individuals: amiodarone, lithium, interferon alpha, and interleukin-2 (American Thyroid Association, 2018).

THE CORTROSYN (LOW DOSE OF SYNTHETIC ACTH TEST)

ACTH regulates the intracellular availability of cholesterol, which is converted into pregnenolone inside the mitochondria. Pregnenolone is the precursor for aldosterone, cortisol, and testosterone. ACTH regulates cortisol and adrenaline production; therefore, ACTH deficiency leads to fatigue, a symptom related to secondary hypothyroidism (Holm, 2016). Cortisol aids in the conversion of T4 to T3 in the liver. T3 is the more active thyroid hormone, which governs most thyroid activities in the body, i.e. hair growth and cycle, when disrupted, leads to hair loss( Beek, et all, 2011).The Cortrosyn (low dose of synthetic ACTH) stimulation test consists in testing the levels of cortisol and ACTH before and after (1 hour later) cortrosyn administration. An abnormal adrenal function is suspected if the levels of cortisol remain the same (Margulies, 2018).

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HYPOTHYROIDISM | BY HEART THROBS | Case Study 23.2 | Group 3

QUESTION 2. What treatment might she require?

Hypothyroidism cannot be cured only treated (American Thyroid Association, 2018). Fifty percent or more of those who have untreated hypothyroidism present hyperlipidemia that can be treated with hormone replacement therapy (Bishop, Fody, & Schoeff, 2018, p. 482. ) Thyroid Hormone replacement therapy in the form of T4 Levothyroxine is the most commonly used treatment (Bishop, Fody, & Schoeff, 2018). This synthetic Thyroxine is identical to the T4 hormone. However dosage is dependant on the history, symptoms and present TSH level of the patient.Treatment is usually accompanied by regular monitoring (McIntosh, 2018). There are not many side effects presented with this treatment; however, if you take too little then you will continue to have hypothyroidism and if you take too much then you will present with hyperthyroidism (American Thyroid Association, 2018). The administration of TRH in patients with pituitary dysfunction will not increase the serum TSH levels, which confirms secondary hypothyroidism (Auburn, 2018). If secondary hypoadrenalism is present, it should be treated simultaneously with secondary hypothyroidism. Evaluate to document hypogonadism or growth hormone deficiency (Loyola University, 2018)

Figure 3 Treatment of Hypothyroidism (David et al., 2012) 7

HYPOTHYROIDISM | BY HEART THROBS | CASE STUDY 23.2 | GROUP 3

QUESTION 3. What other laboratory abnormalities are commonly seen in hypothyroid patients other than hyperlipidemia and abnormal thyroid function tests?

Anemia: Patients with

Low Platelet Adhesion: Another

hypothyroidism can present with anemia in their laboratory results (Bishop, Fody, & Schoeff, 2018).

In 55% of hypothyroidism cases, it is specifically macrocytic anemia (Antonijević, Nesović, Trbojević, & Milosević, 1999). Macrocytic anemia is caused by vitamin deficiencies in B-12 or folate. It is when the blood has an insufficient concentration of hemoglobins, which are responsible for transporting oxygen to the blood (Nagao & Hirokawa, 2017). Pernicious anemia is also very common in patients with hypothyroidism and also occurs as a incomplete absorption of vitamin B-12 (Antonijević, Nesović, Trbojević, & Milosević, 1999).

abnormal laboratory result presented in patients with hypothyroidism is low platelet adhesion (Antonijević, Nesović, Trbojević, & Milosević, 1999).

A test can be used to measure how well one’s blood coagulates. This is assessed through a beaded column, which measures retention levels in blood platelets. (Edson, 1975). Low platelet adhesion could result in the inability for the blood to clot leading to severe bleeding .

Therefore, platelet adhesion is crucial in vascular injury so levels need to monitored in patients presenting with hypothyroidism (Ruggeri & Mendolicchio, 2007).

Elevated CK levels: Creatine Kinase levels may also be elevated in patients.

Creatine kinase (CK) is an enzyme found in the heart, brain, skeletal muscle, and other tissues. CK elevation is known to be related to poor thyroid function.

Increased amounts of CK are released into the blood when there is muscle damage, therefore CK levels can be found by performing a blood test. As hypothyroidism can cause muscle weakness and pain, it can elevate the CK levels in the blood (Greco & Walton-Ziegler, 2018). By testing CK serum levels we can trace the cause of the elevated levels to be due to hypothyroidism. Treatment of hypothyroidism brings CK levels back to normal limits (Beyer et al., 1998).

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HYPOTHYROIDISM | BY HEART THROBS | Case Study 23.2 | Group 3

Diabetes insipidus: (Thirst and heavy intracellular metabolism of cholesterol

urination). A low vasopressin level with elevated plasma osmolality secures the diagnosis for diabetes insipidus (DI), which may be related to the presence of a pituitary tumor (Bishop, Fody, & Schoeff, 2018, p. 469; Loyola University, 2018). This disease can be caused by any injury, be it an injury, genetic defect, or idiopathic cause, that impedes the synthesis, transport, or release of antidiuretic hormone (Makaryus and McFarlane, 2006).

Pituitary dysfunction is related to secondary adrenal insufficiency (lack of ACTH), hypogonadism—patient may present irregular menstruations—and growth hormone deficiency (Bishop, Fody, & Schoeff, 2018).

High Cholesterol Levels: LDL and

HDL cholesterol ratios increased in both genders for primary and secondary hypothyroidism. Upon treatment, primary cases have been known to return to a normal state in contrast to patients with secondary occurrences - lipid panel is still compromised exhibiting lower highdensity cholesterol levels (Zheng, Li, Zhang, & Yang, 2015). High cholesterol levels usually go along with high triglycerides levels under secondary adrenal insufficiency, since ACTH mediates the transport and

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for stereogenic pathways as well as lipolysis (Bishop, Fody, & Schoeff, 2018, p. 442; Woodbury, 2011).

Hormonal Abnormalities: Typically

low thyroid levels related to pituitary dysfunction are associated with other hormonal abnormalities because there is a step-wise dysfunction of the pituitary gland that starts with growth hormone (GH), gonadotropins (GnRH), then thyrotropinn (TRH), and lastly Adrenocorticoid releasing hormone (ACTH) in the presence of an expanding pituitary tumor (California Center, 2016) All of these hormonal pathways are related to release of fatty acid and/or lipid metabolizing related genes. Hence, this favors the atherogenic lipid formation common with excess LDL found in secondary hypothyroidism, which can also be drug-resistant (Zheng, Li, Zhang, & Yang,2015)

HYPOTHYROIDISM | BY HEART THROBS | CASE STUDY 23.2 | GROUP 3

References: American Thyroid Association. (2018). Hypothyroidism. Retrieved September 16, 2018, from https://www. thyroid.org/hypothyroidism/ Antonijević, N., Nesović, M., Trbojević, B., & Milosević, R. (1999). Anemia in Hypothyroidism. Medicinski Pregled 52(3-5), 136-140.

BEYER, I. W., Karmali, R., DEMEESTER-MIRKINE, N. E. L. L. Y., Cogan, E., & FUSS, M. J. (1998). Serum creatine kinase levels in overt and subclinical hypothyroidism. Thyroid, 8(11), 1029-1031.

Bishop, M. L., Fody, E. P., & Schoeff, L. E. (2018). Clinical chemistry principles, techniques, and correlations(8th ed.). Philadelphia: Wolters Kluwer.

Brent, G. A., Weetman, A. P. (2016). Hypothyroidism and thyroiditis. Williams Textbook of Endocrinology.

Chapter 13 Chaudhary, V., & Bano, S. (2013). Thyroid ultrasound. Indian Journal of Endocrinology and Metabolism,17(2), 219. doi:10.4103/2230-8210.109667 David, Y., Gaitonde M. D., Kevin, D., Rowley, D. O., Lory B., Sweeney M. D. (2012) Hypothyroidism: An Update. American Family Physician, 86(1), 244-251 Demers, L. M., & Spencer, C. A. (2003). Laboratory medicine practice guidelines: laboratory support for the diagnosis and monitoring of thyroid disease. Clinical endocrinology, 58(2), 138-140.

Dussault, J. H., Coulombe, P., Laberge, C., Letarte, J., Guyda, H., & Khoury, K. (1975). Preliminary report on a mass screening program for neonatal hypothyroidism. The Journal of pediatrics, 86(5), 670-674.

Edson, J. R. (1975). Low Platelet Adhesiveness and Other Hemostatic Abnormalities in Hypothyroidism.

Annals of Internal Medicine,82(3), 342. doi:10.7326/0003-4819-82-3-342 Ferri, F. F. (2017) Hypothyroidism. Ferri’s Clinical Advisor, 2015:662.

Garber, J. R., Cobin, R. H., Gharib, H., Hennessey, J. V., Klein, I., Mechanick, J. I., . . . Kenneth A. Woeber For The American Association. (2012). Clinical Practice Guidelines for Hypothyroidism in Adults: Cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Thyroid,22(12), 1200-1235. doi:10.1089/thy.2012.0205 Makaryus, A. N., & McFarlane, S. I. (2006). Diabetes insipidus: diagnosis and treatment of a complex disease. Cleveland Clinic journal of medicine, 73(1), 65.

McIntosh, J. (2018, January 02). Hypothyroidism: Causes, symptoms, and treatment. Retrieved from https:// www.medicalnewstoday.com/articles/163729.php Nagao, T., & Hirokawa, M. (2017). Diagnosis and treatment of macrocytic anemias in adults. Journal of General and Family Medicine,18

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