THYROID DISORDERS HOW TO PROPERLY ASSESS, DIAGNOSE AND TREAT YOUR PATIENTS Dacy Gaston South University Dacy Gaston South University

THE ENDOCRINE SYSTEM  The endocrine system is composed of endocrine glands, hormone- producing tissues, hormones, and hormone receptors.  The endocrine gland includes the pineal gland, pituitary gland, thyroid gland, parathyroid glands, thymus gland and adrenal glands.  Several organs and tissues that secrete hormones are also present. These organs include the heart, stomach, pancreas, kidneys, liver, circulatory system, ovaries and testes.  Most importantly, the endocrine system works collaboratively with the nervous system to manage and co-ordinate other body systems. Both systems are involved in maintaining a stable internal environment.  While the glands and tissues of the endocrine system are mostly separated from each other, they work as an integrated system.  The endocrine system is composed of endocrine glands, hormone- producing tissues, hormones, and hormone receptors.  The endocrine gland includes the pineal gland, pituitary gland, thyroid gland, parathyroid glands, thymus gland and adrenal glands.  Several organs and tissues that secrete hormones are also present. These organs include the heart, stomach, pancreas, kidneys, liver, circulatory system, ovaries and testes.  Most importantly, the endocrine system works collaboratively with the nervous system to manage and co-ordinate other body systems. Both systems are involved in maintaining a stable internal environment.  While the glands and tissues of the endocrine system are mostly separated from each other, they work as an integrated system. (Johnstone, Hendry, Farley, McLafferty, 2014)

THE ENDOCRINE SYSTEM

STRUCTURE, FUNCTION AND PATHOLOGY OF THE THYROID GLAND IN THE ENDOCRINE SYSTEM  They Thyroid gland is responsible for the production and secretion of the thyroid hormones, triiodothyronine (T3) and thyroxine (T4).  The thyroid gland is located at the front of the neck and is bilobular in structure. It has two cell types, follicular and parafollicular cells. The follicular cells are responsible for producing thyroid hormones.  They Thyroid gland is responsible for the production and secretion of the thyroid hormones, triiodothyronine (T3) and thyroxine (T4).  The thyroid gland is located at the front of the neck and is bilobular in structure. It has two cell types, follicular and parafollicular cells. The follicular cells are responsible for producing thyroid hormones.

STRUCTURE, FUNCTION AND PATHOLOGY OF THE THYROID GLAND  The thyroid gland is controlled through a feedback system involving the hypothalamus, the pituitary, and the thyroid gland. * This relationship between the hypothalamus the pituitary and the thyroid gland is called the “ HPT axis.”  The Hypothalamus produces TRH (thyrotropin-releasing hormone), which is secreted into the venous system that drains into the pituitary gland. At the pituitary junction, the TRH binds to receptors in thyrotroph cells causing the production and secretion of TSH (thyroid stimulating hormone). The secreted TSH binds to TSH receptors in the follicular cells of the thyroid gland causing the secretion of T4 and T3 into the body.  The thyroid gland is controlled through a feedback system involving the hypothalamus, the pituitary, and the thyroid gland. * This relationship between the hypothalamus the pituitary and the thyroid gland is called the “ HPT axis.”  The Hypothalamus produces TRH (thyrotropin-releasing hormone), which is secreted into the venous system that drains into the pituitary gland. At the pituitary junction, the TRH binds to receptors in thyrotroph cells causing the production and secretion of TSH (thyroid stimulating hormone). The secreted TSH binds to TSH receptors in the follicular cells of the thyroid gland causing the secretion of T4 and T3 into the body. (Chiasera, 2013)

MAINTAINING THYROID HORMONE SECRETION WITHIN RANGE  The amount of hormone released is usually maintained within a particular range. The pituitary gland and hypothalamus regulate themselves through negative feedback.  This process occurs when further secretion is controlled by the hormone itself, or the result of its action, for example, when the pituitary gland releases TSH that in turn stimulate secretion of T4 and T3, when blood levels of those hormones increase, negative feedback stops the release of those hormones and their blood level decreases. Vice Versa, when T4 and T3 decrease below normal range, TSH is released, allowing the process to start again.  The amount of hormone released is usually maintained within a particular range. The pituitary gland and hypothalamus regulate themselves through negative feedback.  This process occurs when further secretion is controlled by the hormone itself, or the result of its action, for example, when the pituitary gland releases TSH that in turn stimulate secretion of T4 and T3, when blood levels of those hormones increase, negative feedback stops the release of those hormones and their blood level decreases. Vice Versa, when T4 and T3 decrease below normal range, TSH is released, allowing the process to start again. (Johnstone, Hendry, Farley, Mclafferty, 2014)

THYROID HORMONE FUNCTION  Thyroid hormones have widespread function effecting metabolism, grown and maturation and other organ specific effects. Metabolically, thyroid hormones are calorigenic in nature and result in oxygen consumption and the generation of body heat.  Given the widespread function on the thyroid hormone, deficiencies and elevations in hormone levels cause many clinical signs and symptoms.  These deficiencies or elevations cross multiple organ systems causing great discomfort for those with associated abnormalities.  Depending on the severity of the disease the presentation of an abnormality may be absent to full blown, and can be difficult for the lay healthcare provider to pick up on the correct signs and symptoms.  Thyroid hormones have widespread function effecting metabolism, grown and maturation and other organ specific effects. Metabolically, thyroid hormones are calorigenic in nature and result in oxygen consumption and the generation of body heat.  Given the widespread function on the thyroid hormone, deficiencies and elevations in hormone levels cause many clinical signs and symptoms.  These deficiencies or elevations cross multiple organ systems causing great discomfort for those with associated abnormalities.  Depending on the severity of the disease the presentation of an abnormality may be absent to full blown, and can be difficult for the lay healthcare provider to pick up on the correct signs and symptoms.

SIGNS AND SYMPTOMS: HYPERTHYROID  Heat intolerance  Flushed skin Flushed skin  Increased appetite  Muscle wasting  Weight loss  Exothalamus  Heat intolerance  Flushed skin Flushed skin  Increased appetite  Muscle wasting  Weight loss  Exothalamus  Tachycardia  Shortness of Breath  Restlessness  Nervousness  Fatigue  Hyperdefecation  Heart Palpitations  Tachycardia  Shortness of Breath  Restlessness  Nervousness  Fatigue  Hyperdefecation  Heart Palpitations

SIGNS AND SYMPTOMS: HYPOTHYROIDISM  Cold intolerance  Dry skin  Lethargy  Generalized Weakness  Weight Gain-unexplained  Bradycardia  Apathy  Cold intolerance  Dry skin  Lethargy  Generalized Weakness  Weight Gain-unexplained  Bradycardia  Apathy  Constipation  Heart Enlargement  Mental Sluggishness  Depression  Constipation  Heart Enlargement  Mental Sluggishness  Depression

CAUSES OF HYPO/HYPER HyperthyroidismHyperthyroidism  Autoimmune (Grave’s)  Thyroiditis  Nodular Disease  TSH producing pituitary adenoma  hCG-mediated  Exogenous thyroid hormone intake  Autoimmune (Grave’s)  Thyroiditis  Nodular Disease  TSH producing pituitary adenoma  hCG-mediated  Exogenous thyroid hormone intake Hypothyroidism  Autoimmune thyroiditis (Hashimoto’s)  Iatrogenic (treatment related)  Post-thyroidectomy  Post Radioactive iodine treatment  Transient thyroiditis  Congenital hypothyroidism  Iodine deficiency  Drugs  Autoimmune thyroiditis (Hashimoto’s)  Iatrogenic (treatment related)  Post-thyroidectomy  Post Radioactive iodine treatment  Transient thyroiditis  Congenital hypothyroidism  Iodine deficiency  Drugs Low prevalence in population approx. 0.3% -0.6% Higher prevalence in population approx. 2%-15%

DIAGNOSTIC TESTS HyperthyroidismHyperthyroidism  TSH  Free T4 Free T3  Thyroid-stimulating immunoglobulin test (TSI)  Thyroid Peroxidase antibody (TPO)  Radioactive iodine uptake test  Thyroid scan  Visualization goiter  TSH  Free T4 Free T3  Thyroid-stimulating immunoglobulin test (TSI)  Thyroid Peroxidase antibody (TPO)  Radioactive iodine uptake test  Thyroid scan  Visualization goiter Hypothyroidism  TSH  Free T4 Free T3  Thyroid Peroxidase antibody (TPO)  Subjective and Objective signs and symptoms from the patient  TSH  Free T4 Free T3  Thyroid Peroxidase antibody (TPO)  Subjective and Objective signs and symptoms from the patient

DIAGNOSTIC INTERPRETATION

TREATMENT HYPOTHYROIDISM

TREATMENT HYPERTHYROIDISM

AACE RECOM 35 SIGNS SYMPTOMS VAST SO PAY ATTENTION TO YOUR PATIENT LEVOTHYROXINE ONLY RECOMMENDED TREATMENT FOR HYPOTHYROID REPLACEMENT REPEAT TESTING ATA AND AACE EVERY 3 MONTHS UNTIL EUTHYROID THEN EVERY Q?