1 / 65

Thyroid Diseases

Thyroid Diseases. Scott Urquhart, PA-C Clinical Instruct., George Washington Univ. PA Program Adjunct Clinical Prof., James Madison Univ. PA Program Diabetes and Thyroid Associates. Fredericksburg, Virginia. Q1: The most common thyroid function disorder is?. 1) Graves’ disease

lula
Download Presentation

Thyroid Diseases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Thyroid Diseases Scott Urquhart, PA-C Clinical Instruct., George Washington Univ. PA Program Adjunct Clinical Prof., James Madison Univ. PA Program Diabetes and Thyroid Associates. Fredericksburg, Virginia

  2. Q1: The most common thyroid function disorder is? • 1) Graves’ disease • 2) Hypothyroidism • 3) Sub-acute thyroiditis • 4) Thyroid cancer

  3. Q2: The most sensitive test for thyroid function is? • 1) Free T4 • 2) Free T3 • 3) TSH • 4) Thyroid ultra sound

  4. Q3: The best assay to confirm that a patient’s hypothyroidism is autoimmune in nature? • 1) Thyroid stimulating immunoglobulins • 2) Anti-nuclear antibody • 3) TSH • 4) Thyroid peroxidase antibodies

  5. Q4: The best assay to confirm that a patient’s hyperthyroidism is autoimmune in nature? • 1) Thyroid stimulating immunoglobulins • 2) Anti-nuclear antibody • 3) TSH • 4) Thyroid peroxidase antibodies

  6. Q5: Which is the best study to confirm the etiology of a patient’s thyrotoxicosis? • 1) I123 thyroid scan/uptake • 2) Neck CT or MRI • 3) Thyroid ultrasound • 4) Fine needle aspiration of the thyroid

  7. Q6: Which is the best study to make the initial evaluation for thyroid nodules discovered on routine physical exam? • 1) I123 thyroid scan/uptake • 2) Neck CT or MRI • 3) Thyroid ultrasound • 4) Fine needle aspiration of the thyroid

  8. Q7: Patient has a thyroid U/S showing a solid dominant (>10mm) nodule and normal thyroid function, what is your next step? • 1) Re-check thyroid U/S in 1 year • 2) Fine needle aspiration of the thyroid • 2) Neck CT or MRI • 4) I123 thyroid scan/uptake

  9. Q8: Thyroid U/S shows homogeneous increased radiotracer uptake, the diagnosis is? • 1) Metastatic thyroid cancer • 2) Graves’ disease • 3) Toxic multi-nodular goiter • 4) Toxic thyroid nodule

  10. Q9: Methimazole or propylthiouracil and used to treat hypothyroidism? • 1) True • 2) False

  11. Q10: Which in not an appropriate treatment for Graves’ disease? • 1) Thyroidectomy • 2) Anti-thyroid medications such as propylthiouracil or methimazole • 3) Levothyroxine sodium • 4) I131 radioactive iodine

  12. OBJECTIVES • Order and interpret appropriate labs and studies necessary for the diagnosis of the thyroid disorders discussed in this lecture. • Describe the common signs and symptoms of hyper/hypothyroidism, work-up, treatment, and follow-up. • Provide a practical approach to the work-up and diagnosis of thyroid nodules. • Know when to refer.

  13. Thyroid Diseases Scott Urquhart, PA-C Clinical Instruct., George Washington Univ. PA Program Adjunct Clinical Prof., James Madison Univ. PA Program Diabetes and Thyroid Associates. Fredericksburg, Virginia

  14. Major Thyroid Abnormalities Functional / Biochemical Structural / Anatomy • Thyroid • Goiter • Nodules • Cold • Warm or Hot • Cysts • Malignancies • Hypothyroidism • Hyperthyroidism

  15. At Risk Population for Thyroid Dysfunction • Women, elderly, postpartum 4-8 months. • FamHx of Hashimoto’s or Graves’ dz. • PMHx or FamHX autoimmune diseases – SLE, RA, DM1, Addison’s, vitiligo, pernicious anemia. • Type 1 DM: ~20% increase risk for thyroid dysfunction, mainly hypothyroid. • Patients treated with amiodarone, lithium, others. Am. Thyroid Association, postpartum thyroiditis, accessed 6/4/2011 AACE Thyroid Guidelines, Endocr Pract. 2002;8(No. 6) Basic and Clinical Endocrinology, Lange Series, 7th edition

  16. HYPOTHALAMIC / PITUITARY THYROID AXIS • TRH: stimulate anterior pituitary to release TSH. • TSH:stimulate thyroid for synthesis and release of T4 and T3. • Low T4, Low T3: stimulate TSH and TRH. • High T4, High T3: inhibit TSH and TRH. Basic and Clinical Endocrinology, Lange Series, 7th edition

  17. THYROID HORMONES • T4 to T3 secretion ratio of 10:1. • T3 is 4X more biologically active than T4. • T1/2: T4 = 7days, T3 = 1 day. • T4,T3: 99% bound to protein, i.e. metabolically inactive. • From thyroid: 100% - T4, 20% - T3 remainder of T3 is from T4 to T3 conversion in peripheral tissues. Basic and Clinical Endocrinology, Lange Series, 7th edition

  18. THYROID TESTINGBiochemical 1) TSH - highly sensitive, best test for thyroid function. • Free T4 (FT4)- biologically active. • Free T3 (FT3) - biologically active. - rarely need to check unless, TSH is low or undetectable with a normal FT4.

  19. THYROID TESTING(more specific) • Thyroid Peroxidase Antibodies (TPO-Ab’s) - Hashimotos Thyroiditis • Thyroid Stimulating Immunoglobulins (TSI’s) or TSH receptor antibodies (TRAb). - Unique to Graves’ disease • I-123 RAIU (Radio Active Iodine Uptake) evaluation for thyrotoxicosis, shape, size. Don’t use to confirm hypothyroidism.

  20. DON’T FORGET THE BASICS • History of present illnessand ROS. • PMHx – postpartum • Past Hx of thyroid pain/tenderness/nodule/ enlargement or goiter • H/O autoimmune diseases • FamHX – thyroid dysfunction, thyroid cancer, Autoimmune diseases. • Medications • Systematic physical exam

  21. Hypothyroidism

  22. HYPOTHYROIDISM • Prevalence: 4 - 8% general population. • Mean age of Dx: 5th decade of life • Female to male ratio: 10:1 Endocrine Secrets. McDermott, 4rd Edition

  23. PRIMARY HYPOTHYROIDISM • Identification on clinical basis can be challenging. • Symptoms generally vague. • Frequently goes unnoticed, confused as other health problems. • Insidious onset + poor index of suspicion = misdiagnosis

  24. ETIOLOGY • Autoimmune: - Chronic lymphocytic thyroiditis = Hashimoto’s - positive TPO-Ab’s - remember postpartum thyroiditis • Iatrogenic: I-131 RAI, total/subtotal thyroidectomy, neck irradiation. • Congenital: agenesis, dysgenesis. • Drug induced: lithium, amiodarone, chemotherapy, others. Endocrine Secrets. McDermott, 4rd Edition Basic and Clinical Endocrinology, Lange Series, 7th edition

  25. Clinical Symptoms of Hypothyroidism • Fatigue • Lethargy • Cold intolerance • Constipation • Decreased memory • Depression • Mental Impairment • Arthralgias • Hoarseness • Heavy menstrual flow • Paresthesias • Sleepiness • Weight gain ,edema • Muscle cramps AACE Thyroid Guidelines, Endocr Pract. 2002;8(No. 6) Braverman LE, et al. Werner & Ingbar’s The Thyroid. A Fundamental and Clinical Text. 8th ed. 2000.

  26. Clinical Signs of Hypothyroidism • Bradycardia • Coarse hair, hair loss • Delayed relaxation phase of deep tendon reflexes • Dry, cool, pale skin • Goiter • Hoarseness • Non-pitting edema (myxedema) • Puffy eyes and face • Slow movements • Slow speech • Thinning lateral third of eyebrows AACE Thyroid Guidelines, Endocr Pract. 2002;8(No. 6) Braverman LE, et al. Werner & Ingbar’s The Thyroid. A Fundamental and Clin. Text. 8th ed. 2000.

  27. Example of Clinical Manifestationsof Hypothyroidism • Patient example • Fatigue (“no energy”), cold intolerance, constipation, weight gain, fatigue, problems with concentration (“mental clouding”), dry skin

  28. CLINICALMANIFESTATONSEXAM • NECK: thyroid may be normal, enlarged, symmetric/asymm., smooth or lumpy. • HEART: bradycardia. • EXTREMS: pretibial/ankle edema, dry cool skin, brittle nails. • NEURO: DTR’s with delayed relaxation phases • HEENT: periorbital puffiness, loss of lateral eyebrows, coarse/thinning hair.

  29. LABORATORY EVALUATION • TSH - high • Free T4 - low • Check both if new diagnosis to make sure PITUITARY-THYROID AXIS intact. • Consider TPO-Ab

  30. Levothyroxine Sodium (LT4 ) • Exogenously administered LT4 hormone • Indistinguishable from endogenous T4, both in its physiologic effects and its quantification as measured in blood • LT4 is the treatment of choice as replacement or supplemental hormone therapy • Branded preparations are preferred Levothyroxine Bioequivalence Briefing Document. Available at: http://www.fda.gov/ohrms/dockets/ac/03/briefing/3926B1_02_A-abbott.pdf

  31. TREATMENT • Levothyroxine (LT4), narrow therapeutic range • 0.3 – 3.0 IU/mL, caution in lower range TSH. • Brand vs. generic vs. T4 + T3 combination. • Lifelong treatment, most cases • Dosing: 1.6 mcg/kg/day = ~100 - 125 mcg/day. • Compliance, empty stomach, competing agents for absorption (Iron, Calcium ) • Check TSH no sooner than 6 weeks after initial start of LT4 or any adjustment. AACE Thyroid Guidelines, Endocr Pract. 2002;8(No. 6)

  32. Therapy Monitoring • Clinical and laboratory monitoring enable • Evaluation of the clinical response • Assessment of patient compliance • Assessment of drug interactions, if applicable • Adjustment of dosage, as needed • Clinical and laboratory evaluations should be performed • At 6- to 8-week intervals while titrating • Annually once a euthyroid state is established

  33. Factors That May Reduce Levothyroxine Effectiveness • Malabsorption Syndromes • Post jejunoileal bypass surgery • Short bowel syndrome • Celiac disease • Reduced Absorption • Colestipol hydrochloride • Sucralfate • Ferrous sulfate • Food (eg, soybean formula) • Aluminum hydroxide • Cholestyramine • Sodium polystyrene sulfonate • Drugs That Increase Clearance • Rifampin • Carbamazepine • Phenytoin • Factors That Reduced T4 to T3 Clearance • Amiodarone • Selenium deficiency • Other Mechanisms • Lovastatin • Sertraline Braverman LE, Utiger RD, eds. The Thyroid: A Fundamental and Clinical Text. 8th ed. 2000. Synthroid® [package insert]. Abbott Laboratories; 2003.

  34. Thyroid Hormone TherapySpecial Treatment Populations • Patients 50 years of age or with underlying cardiac disease • Initial dose of LT4 - 25 to 50 mcg/d • Elderly patients with cardiac disease • Initial dose of LT4 - 12.5 to 25 mcg/d • Patients with heart failure • Both hypo- and hyperthyroidism can worsen heart failure Levothyroxine Bioequivalence Briefing Document. Available at: http://www.fda.gov/ohrms/dockets/ac/03/briefing/3926B1_02_A-Abbott.pdf

  35. Treating Hypothyroidism Before and During Pregnancy • Encourage adherence with LT4 replacement therapy before conception • Monitor TSH levels before conception and during first trimester • Consider increase of LT4 dosage in athyreotic patients by 25% - 50% when pregnancy is confirmed • Monitor TSH levels every 6 to 8 weeks throughout pregnancy • Reinstate pre-pregnancy LT4 dosage immediately following delivery Gharib H, et al. Endocr Pract. 1999;5:367-368. Mandel SJ, et al. N Engl J Med. 1990;323:91-96.

  36. Over-Replacement Risks • Switching a narrow therapeutic index drug, such as LT4, without retesting and re-titrating can cause inconsistent TSH control, resulting in over-replacement • Over-replacement risks (TSH <0.5 IU/mL) • Iatrogenic thyrotoxic state • Increased heart rate and myocardial contractility • For cardiac patients, increased risk of angina and MI • Reduced bone density/osteoporosis • Psychiatric symptoms, such as anxiety, sleep disturbance, irritability, and fatigue Synthroid® [package insert]. Abbott Laboratories; 2003. Braverman LE, et al. Werner & Ingbar’s The Thyroid. A Fundamental and Clinical Text. 8th ed. 2000. Felicetta JV. Consultant. 2002;1597-1606. Available at: www.consultantlive.com. Accessed July 1, 2003.

  37. Case 1 46 y.o. female presents with a 3 - 4 month history of heavier than usual menstrual cycles, fatigue, “feeling sleepy all of the time”, depressed, constipation, problems concentrating, cold intolerance. • PMHx: unremarkeable • FAMHx: Adopted.

  38. Case 1 continued • P.E. : DTR’s show delayed relaxation phases of biceps and brachioradialis, non tender symmetric goiter @ 2 times normal size without nodules. • LABS : TSH 77.02 (0.45-4.50) Free T4 0.38 (0.8 – 1.50) TPO-Ab 267 reactive greater 40.

  39. Case 1 continued • Dx: Hashimoto’s Thyroiditis • Tx: 100 mcg qd, non-generic LT-4 Follow-up in 6 weeks and recheck TSH • F/U: Feeling “90% better” TSH 7.62 Increase to 112mcg qd. Follow-up in 2 months. • 2 months later TSH – 2.11 (0.50 - 3.00). Plan: follow and adjust LT-4 based on TSH

  40. SUBCLINICAL HYPOTHYROIDISM • Very difficult to diagnose clinically • High index of suspicion, may be asymptomatic • 4 -15% of general population* • 20% of pts. over 60 y.o. (esp. women)** • LABS: TSH - minimally high (6 - 10 IU/mL) Free T4 – low normal • TREATMENT: controversial, consider if symptoms, lipid abnormality, if TPO-Ab positive • Low dose LT-4 vs. surveillance, education. *US Endocrinology Volume 4 Issue 1 *www.aace.com accessed 6/4/2011

  41. Mild Thyroid Failure and Neurobehavioral Abnormalities • Conditions reported to occur more frequently in patients with mild thyroid failure • Depression • Anxiety • Somatic complaints • Cognitive abnormalities Braverman LE, et al. Werner & Ingbar’s The Thyroid. A Fundamental and Clinical Text. 8th ed. 2000. Cooper DS. N Engl J Med. 2001;345:260-264.

  42. Rationale for Treating Mild Thyroid Failure • Potential benefits from treatment • Prevent progression to overt hypothyroidism • Improve serum lipid profile, which may reduce the risk of death from cardiovascular causes • Reduce symptoms, including psychiatric and cognitive abnormalities Cooper DS. N Engl J Med. 2001;345:260-264.

  43. Case 2 • Hx: 32 y.o. women referred for mildly increased TSH 8.69 (0.46-4.68) • Symtoms: mild fatigue, dry skin, “not feeling my usual self” • PMHx: no H/O thyroid disorders, or recent of remote thyroid pain/tender. • FAMHx: Mother, two maternal aunts with hyperthyroidism.

  44. Case 2 continued • P.E. : Thyroid minimally enlarged and non-tender, no nodules. remainder of exam unremarkable. • Labs: TSH 7.5 (.46 – 4.68) FREE T4 0.82 (0.80-1.50). TPO-Ab 317 reactive greater than 40

  45. Case 2 continued • DX:Subclinical Hypothyroidism • Hashimotos thyroiditis • Tx: “Brand LT4” 25 mcg q.d. Follow-up and TSH in 2 months. • Follow-up: patient feeling better without complaints TSH 1.89 (0.5 – 3.0) Education, need to follow

  46. Hyperthyroidism

  47. HYPERTHYROIDISMETIOLOGY • Graves’ disease ( autoimmune ). • Toxic multi-nodular goiter ( toxic MNG ). • Toxic nodule (hot or warm nodule)

  48. Common Symptoms and Signs of Thyrotoxicosis Symptoms • Nervous / shaky • Fatigue • Muscle weakness • Increased perspiration • Heat intolerance • Tremor • Palpitations • Appetite/weight changes • Menstrual disturbances Signs • Goiter • Hyperactivity • Tachycardia / arrhythmia • Systolic hypertension • Warm, moist, or smooth skin • Stare and eyelid retraction • Tremor • Hyper-reflexia Braverman LE, et al. Werner & Ingbar’s The Thyroid. A Fundamental and Clinical Text. 8th ed. 2000.

  49. GRAVES’ Dz • ~75% of cases of hyperthyroidism. • Thyroid Stimulating Immunoglobulins (TSI’s) and / or TSH receptor antibodies (TRAb) levels usually increased • Incidence 2nd – 4th decade of life. • ~5 times more likely in women. Basic and Clinical Endocrinology, Lange Series, 7th edition

  50. Thyrotoxicosis - work-up • Labs- demonstrate thyrotoxicosis. • TSH - Low or undetectable • Free T4 and/or Free T3 – Increased I123 thyroid scan / uptake • Uptake is increased. • 4 hour: normal ref. (5 – 15%) • 24 hour: normal ref. (6 - 30%) • Scan (anatomical findings via radiotracer uptake) • Homogeneous ( Graves’ Dz) • multiple areas (Toxic MNG) • single area (Hot or warm nodule) Hyperthyroidism Management Guidelines, Endocr Pract. 2011;17(No. 3)

More Related