Upload
dangxuyen
View
218
Download
0
Embed Size (px)
Citation preview
1
Who should have a thyroid eval?What do those labs mean?What causes hypothyroidism?Should I treat subclinical cases?How do I give ADTs and RTH?…What’s for lunch?
Christine Kessler RN, MN, CNS, ANP-BC, BC-ADMWashington D.C./Bethesda, MD/Fort Belvoir, VA
Managing Hyper- & Hypothyroid Disorders in Clinical Practice
Objectives:At the conclusion of this session, the participant will be
able to:1. Relate underlying physiology of thyroid hormone
production to diagnostic and assessment findings.
2. More accurately interpret thyroid-related laboratory findings and discern factors that may adversely affect accuracy of findings.
3. Analyze selected case studies for the diagnosis and treatment of various abnormal thyroidal conditions.
4. Discuss the cardiovascular impact of hyper-and hypothyroidism.
Questions• When should you screen for thyroid
dysfunction?
• Is TSH the best laboratory screening for thyroid disorders?
• What are other pertinent diagnostic data and how do they relate to thyroid pathology?
• What are the most common forms of hyper- & hypothyroidism?
• Should subclincal cases be treated?
• Can armour thyroid or T3 be used as replacement therapy
2
Case 1A 75 yo woman c/o “slowing down” & feeling a “little
forgetful.” She has constipation. BP 156/88; HR 62 regular; Physical exam normal for age:
LAB: TSH 9.0 (0.5-4.5 mU/L) FT4 1.1 (0.8-1.8 ng/dL), normal chemistry. Lipids not done
Which of the following actions would be most appropriate?A. Initiate treatment of levothyroxine 25 mcg/day &
recheck TSH in 6 weeks.B. Check lipid profile and start her on treatment if her LDL
is high.C. Check FT3, if low initiate therapy with levothyroxine.D. Check anti-TPO, and repeat TSH & FT4 in 2 – 6 weeks.
Case 2A 60 yo male with history htn, dm type 2, and
hyperlipidemia.MEDS: lisinopril, HCTZ, glipizide XL, and simvastatin. VS: 98.5, HR 98 (reg), resp rate 18, BP 118/78Phys exam is unremarkable. LABS: TSH 0.18 (0.45 – 5.0 mU/L), FT4 1.6 (0.8 – 1.8
ng/dL), FT3 3.5 (1.5-7.0 pmol/L). Chem panel/lipids normal. EKG is also normal
Which of the following statements would be appropriate?A. He has subclinical hypothyroidism with increased risk of develop
osteosporosis & atrial fibrillation so start treatment.B. Check anti-TPO. If it’s positive he will likely develop Graves’
disease in the future.C. He should have thyroid ultrasound, and start ATD.D. He should have a repeat TSH and FT4 in 3 – 6 weeks along with
anti-TPO.
Prevalence of thyroid disorders
• 10 million diagnosed—13 million undiagnosed
• 360,000 new cases each year• 1:8 women will have thyroid problems in
her lifetime (5x>men)• By 60 yrs 20% woman have a thyroid
problem• 40% pts taking thyroid meds have
abnormal TSH!!
3
Canaris GJ, et al. Arch Intern Med. 2000;160:523-534.
Prevalence of Thyroid Disease by Age
Elevated TSH, %(Age in Years)
18 25 35 45 55 65 75
Male 3 4.5 3.5 5 6 10.5 16
Female 4 5 6.5 9 13.5 15 21
•The incidence of thyroid disease increases with age
Are You at Risk?
• Hx of endocrine problem, autoimmune disease
• Fibromyalgia• Female• 60 y/o• Had baby recently or menopausal• Smoker or exposed to radiation• Lithium, amiodarone, excessive flouride
or soy products
When should we screen for thyroid dysfunction?
4
Screening for Thyroid Dysfunction Recommendations for Asymptomatic Adults
OrganizationAmerican Thyroid Association
American Association ofClinical Endocrinologists
American College ofPhysicians
Screening RecommendationWomen and men >35 years of age should be screened every 5 years
Older patients, especially women, should be screened—no mention of age
Screening only in asymptomatic patients older than 60.
Ladenson PW, et al. Arch Intern Med. 2000;160:1573-1575.Cooper DS. N Engl J Med. 2001;345:260-265
Baskin HJ.AACE Thyroid Guidelines, Endocr Pract. 2002;8(No. 6) revised 2002.
Screening for Thyroid Dysfunction Recommendations for Asymptomatic Adults
OrganizationRoyal College of Physicians of London, and the U.S. Preventive Services Task Force (USPSTF)
BUT:…there are ATA pregnancy guidelines:
Screening RecommendationDo not recommend any routine screening for thyroid disease in adults
Check thyroid prior to pregnancy (if at risk) and .during first trimester
Screening for Thyroid Disease: Agency for Healthcare Research and QualityU.S. Department of Health and Human Services. 2004.
.
Joint Statement of AACE, ATA andEndocrine Society:
Lack of definitive evidence for a benefit does not equate to evidence for lack of benefit. Potential benefits of early detection and treatment of subclinical thyroid dysfunction outweigh the potential side effects that could result from early detection and therapy….Therefore, we favor screening for subclinical thyroiddysfunction in adults, including pregnant women andthose contemplating pregnancy.
Thyroid, January, 2005
5
Pregnancy: What ThryoidScreening?
• Ideally, check TSH preconception/ first trimester:
• 0.4-2.5 mU/L: do not need to recheck during preg
• 2.5-5.0 mU/L: recheck TSH during 1st trimester– Check thyroid antibodies—IF THEY ARE
POSITIVE—TREAT SUBCLINICAL HYPOTHYROIDISM
What Do Thyroid Hormones Do?
The great SYNERGIZERIncreases fetal development (synergy with GH)
Increases MVO2, CO, HR
Increased B-adrenergic Beta receptor in heart
Stimulates gut motility and protein catabolism
Major impact on menses and fertility
Lipid Effects of T3
• Stimulates lipolysis and release of free fatty acids and glycerol
• Induces expression of lipogenic enzymes
• Effects cholesterol metabolism• Stimulates metabolism of cholesterol to bile
acids• Facilitates rapid removal of LDL from plasma
6
T4
T3
Hypothalamic-Pituitary-Thyroid Axis
Physiology
Pituitary
Thyroid Gland
Hypothalamus TRH
T4 T3
Liver
T4 T3
Heart
Liver
Bone
CNS
TR
Target Tissues
–
–
TSH
Adapted from Merck Manual of Medical Information. ed. R Berkow. 704:1997.
Production of T4 and T3
• T4 is the primary hormone of the thyroid gland, nearly 9-10x more T4 than T3
• T3 released in very small amounts from thyroid (but is MOST physiologic)
– About 80% of circulating T3 comes from deiodination of T4 in peripheral tissues
– About 20% comes from direct thyroid secretion
Carriers for Circulating Thyroid Hormones
• More than 99% of circulating T4 is bound to plasma carrier proteins---less T3– Thyroxine-binding globulin (TBG), binds
about 75%– thyroxine-binding prealbumin , albumin,
HDL binds the rest– Carrier proteins can be affected by
physiologic changes, drugs, and disease
7
What Can Go Wrong?
Hypothyroidism
Hyperthyroidism
Thyroid nodules/cancer
The problem can be
Intrinsic: thyroid
Extrinsic: H-P disorders
Or dietary/ medication/ acute illness problems
What are the MOST important labs to know?
• TSH
• FT4
• FT3• Thyroid
antibodies
TSH—The Gold Standard
• Assess HPA axis—feedback system
• Less errant than FT4
• Most sensitive for subclinical thyroid disease (98%) & specific (92%)
• Not as useful in central diseases
8
Thyroid Testing
• TSH (0.5-4.5 uU/ml) BUT 0.3-3.0 more appropriate
– Best test for screening for thyroid dysfunction!
– Log/linear response w/ FT4• A 2-fold change in FT4 produces a 100-fold
change in TSH
– Not specific for a particular thyroid disease.• Don’t use TSH alone for diagnosis!
– Also useful in• Assessing thyroid Rx in primary hypothyroidism
• Monitoring TSH-suppressive tx in thyroid Ca
TSH Accuracy Affected By:• Age-increased
• Pregnancy: 1st trimester increased; then decreased
• Critical illness
• Drugs: – Dopamine, steroids—decreased
– Amiodarone, heroin—increased
TSH Findings
• Hypothyroidism (primary) increased
• Hypothyroidism (secondary) decreased
• Hyperthyroidism (primary) decreased
• Hyperthyroidism (secondary) increased
•TSH is less reliable during first 2-3 months of thyroid replacement therapy
9
TSH Targets in Pregnacy
• The new recommendations for TSH levels during pregnancy are the following:
• First trimester: less than 2.5 with a range of 0.1-2.5
• Second trimester: 0.2-3.0
• Third trimester: 0.3-3.0.
Stagnaro-Green A, Abalovich M, Alexander E, et al. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid. 2011;21:1081-1125
10-20% women have reduced TSH with HCG peak
Thyroid Testing• FT4 (0.7-1.9 ng/dl)
– Testing methods: various(check if abnormal TSH)
– Indications:• In conjunction w/ TSH for DX hyperthyroidism or
hypothyroidism.• Monitoring ATD in central hypothyroidism • Assessing response to 131-RAI• Monitoring ATD tx in pregnancy
• FT3 (230-619 pg/dl)– Abnormal TSH + normal FT4, then check for T3
Thyrotoxicosis
10
FT4 Findings
• Inverse relationship with TSH• More reliable in unstable thyroid
status• More affected by other variables• Genetic FT4 set-point likely
• Hyperthyroidism: increased!• Hypothyroidism: decreased!• Subclinical varied
Typical Thyroid Hormone Levels in Thyroid Disease
TSH T4 T3
Hypothyroidism High Low Low
Hyperthyroidism Low High High
TSH
HIGH
LOW
FT4 Clinical StatusLOW Primary Hypothyroidism, Thyroiditis (stage 3)
NORMAL Subclinical Hypothyroidism
HIGH Pituitary (secondary) Hyperthyroidism
HIGH Thyrotoxicosis, Thyroiditis (stage 1)
NORMAL Subclinical Hyperthyroidism, Autonomous nodules
LOW Pituitary (secondary) Hypothyroidism
Overview of Thyroid Function Tests
11
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
Antithyroid Antibodies
• Thyroid peroxisome -- Anti-TPO– 95% sensitive for Hashimotos– Less sensitive for Graves– False positive too
• TSH receptor stimulator (TSI)—found in 85% Graves disease
• Thyroglobulin: Monitor RX with RAI or Rx for thyroid CA
Ancillary Testing
• Radioactive uptake (RAIU)- scans
• Ultrasound
12
Thyroid Ultrasound
Thyroid nodules
Case Study:
54 y/o woman with hypothyroidism (Hashimoto’s) for 21 years--on stable Synthroid dose of 150 mcg/day. Her TSH has dropped abruptly.
Recently dx’d with HTN, HLD, and T2DM. On metformin XR 1500 mg daily, lisinopril 20 mg, lipitor 20 mg.
What does her fall in TSH mean and what may have caused it?
13
Hyperthyroidism• Hyperthyroidism refers to excess synthesis
and secretion of thyroid hormones by the thyroid gland, which results in accelerated metabolism in peripheral tissues
•Incidence ranges from
–1.9% to 2.7% in women
–0.16% to 0.23% in men
Bahn Chair RS, Burch HB, Cooper DS, et al. Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists. Thyroid. 2011;21:593–646
HyperthyroidismUnderlying Causes
– Toxic diffuse goiter (Graves disease)
– Toxic uninodular or multinodular goiter
– Toxic adenoma
– Painful subacute thyroiditis
– Silent thyroiditis
– Iodine and iodine-containing drugs and radiographic contrast agents
– Trophoblastic disease, including hydatidiform mole
– Exogenous thyroid hormone ingestion
Nervousness/Tremor
Mental Disturbances/ Irritability
Difficulty Sleeping
Bulging Eyes/Unblinking Stare/ Vision Changes
Enlarged Thyroid (Goiter)
Menstrual Irregularities/Light Period
Frequent Bowel Movements
Warm, Moist Palms
First-Trimester Miscarriage/Excessive Vomiting in Pregnancy
Hoarseness/Deepening of Voice
Persistent Dry or Sore Throat
Difficulty Swallowing
Palpitations/Tachycardia
Impaired Fertility
Weight Loss or Gain
Heat IntoleranceIncreased Sweating
Family History ofThyroid Disease
or Diabetes
Signs and Symptoms of Hyperthyroidism
Sudden Paralysis
14
FT4 Levels & Atrial Fibrilation
Selmer C, Olesen JB, Hansen ML, et al. The spectrum of thyroid disease and risk of new onset atrial fibrillation: A large population cohort study. BMJ 2012; DOI:10.1136/bmj.e7895. Available at: http://www.bmj.com
Graves Disease(Toxic Diffuse Goiter)
The most common cause of hyperthyroidism– Accounts for 60% to 90% of cases– Affects females >males– Graves disease is an
autoimmune disorder
Presents with goiter,exophthalmia, dermopathy
Labs: TSI, anti-TPO
Thyroid Acropachy
Thyroid acropachy. This is most marked in the index fingers and thumbs.
15
Onycholysis
Graves’ Dermopathy
Thyroid Dermopathy
– Thickening and redness of the dermis
• Due to lymphocytic infiltration
– Distribution
• Pretibial > 90%
• May include feet
Pink and skin coloured papules, plaques on the shin
Hyperthyroid Eye Disease• Hyperthyroidism (any cause)
– Lid lag, lid retraction and stare
• True Graves’ Ophthalmopathy– Proptosis– Diplopia– Inflammatory changes
• Conjunctival injection• Periorbital edema
16
Exophthalmus
Cranial nerve palsy
DiagnosisAssessment data:
Cardiovascular
Neuromuscular
Dermatological
Thyroid palpation Lab Data
TSH ;FT4 ; FT3
TSI, thyroid scan, US
TreatmentADTs almost always work
Methimazole is first choiceEXCEPT in first trimester, thyroid storm, or if Methimazole intolerance
Dose: 10-20 mg/day PO; after euthyroidism is achieved, reduce by 50% & administer for 12-18 months
PTU: drug of choice in uncommon situations of life-threatening severe thyrotoxicosis. May be preferable during & before the first trimester.
Dose: 300-450 mg/day PO divided q8hr initially (may require up to 600-900 mg/day)
Maintenance: 100-150 mg/day divided q8hr
17
Further Treatment
• Prolonged ATD use in toxic nodular goiter
• Radioactive Iodine
• Potassium iodide (Lugol's solution) is primarily administered for 10 days before thyroidectomy or during thyrotoxic crisis
• Non-selective beta blockers
• Surgery for MNG (RAI if needed), CA
Treatment Pointers
• Antithyroid drugs block thyroid hormone synthesis—usually short term Rx, dose individualized
• Treatment of subclinical hyperthyroidism– Yes, maybe, and no
– Consider pts at risk of atrial fibrillation/ osteoporosis
Thyroid Storm
• Exaggeration of hyperthyroid signs
• Tachycardia pronounced• Heart failure • Patient in a meltdown!!!
18
Case Study:
63 y/o woman, with hx of HLD and HTN,
Presents TSH of 0.12 mlU/ml (0.45-4.5) & FT4 of 1.0 ng/dl (4.5-11).
She is asymptomatic.
What is her diagnosis and how (or will) you treat her?
Hypothyroidism
• Hypothyroidism is a disorder with multiplecauses in which the thyroid fails to secrete an adequate amount of thyroid hormone
– The most common thyroid disorder
– Usually caused by primary thyroid gland failure
– Also may result from diminished stimulation of the thyroid gland by TSH (secondary)
Incidence of Hypothyroidism
• Woman 5-10x > men• 6-9% woman; 21% by 75 yrs
(16% in men)• 1:4000 neonates
19
Primary Hypothyroidism: Underlying Causes
• Congenital hypothyroidism– Agenesis of thyroid– Defective thyroid hormone synthesis
• Thyroid tissue destruction as a result of– Chronic autoimmune (Hashimoto) thyroiditis– Radiation (like radioactive iodine treatment for thyrotoxicosis)– Thyroidectomy– Other infiltrative diseases of thyroid (eg, hemochromatosis)
• Drugs with antithyroid actions (eg, lithium, iodine, iodine-containing drugs, radiographic contrast agents, interferon alpha)
Subclinical Hypothyroidism
• Subclinical hypothyroidism affects 2-3% of women in pregnancy.
Common Features of Hypothyroidism
Hypothermia
Hypoventilation
Bradycardia
20
Tiredness
Forgetfulness/Slower Thinking
Moodiness/ Irritability
Depression
Inability to Concentrate
Thinning Hair/Hair Loss
Loss of Body Hair
Dry, Patchy Skin
Weight Gain
Cold Intolerance
Elevated Cholesterol
Family History of Thyroid Disease or Diabetes
Muscle Weakness/Cramps
Constipation
Infertility
Menstrual Irregularities/Heavy Period
Slower Heartbeat
Difficulty Swallowing
Persistent Dry or Sore Throat
Hoarseness/Deepening of Voice
Enlarged Thyroid (Goiter)
Puffy Eyes
Clinical Features of Hypothyroidism
Diagnosis Algorithm for Hypothyroidism
TSH0.4 to 4.0 IU/mL
PatientEuthyroid
TSH<0.4 IU/mL
Patient Hyperthyroid?Hyperthyroidism
Diagnosis
TSH>4.0 IU/mL
Go to Next Step
SuspectHypothyroid? Test TSH
Primary Hypothyroidism Diagnosis Algorithm
FT4 High
ConsultEndocrinologist
for PossibleTSH-Secreting
Pituitary Tumor orThyroid Hormone
Resistance
TSH >4.0 IU/mL Test FT4
*Free T4 estimate
FT4
Low
PatientHypothyroid
HypothyroidismManagement
FT4
Normal
HypothyroidismManagement
PatientSubclinicalHypothyroid
Demers LM, Spencer CA, eds. The National Academy of Clinical Biochemistry Web site. Available at: http://www.nacb.org/lmpg/thyroid_lmpg.stm. Accessed July 1, 2003.
Ayala AR, et al. Cleve Clin J Med. 2002;69:313-320.
Ayala AR, et al. The Endocrinologist. 1997;7:44-50.
Endocr Pract. 2002;8:457-469.
21
Diagnostic Studies of Hypothyroidism
• High TSH, low FT4 +/or FT3
• Elevated Anti-TPO or anti-TG in Hashimotos thyroiditis
• Abnormal thyroid scan
• Lipids, electrolytes, EKG, LFTs
Cholesterol Levels Elevate With Increasing TSH Levels
Canaris GJ, et al. Arch Intern Med. 2000;160:526-534.
209216
223 226229
238 239
270 267
200
210
220
230
240
250
260
270
280
Mea
n To
tal C
hole
ster
ol
Leve
l, m
g/dL
<0.3 0.3-5.1
>5.1-10
>10-15
>15-20
>20-40
>40-60
>60-80
>80
TSH, IU/mL
Abnormal
Euthyroid
Definition of Mild Thyroid Failure
• Elevated TSH level (>4.0 IU/mL)
• Normal total or free serum T4
and T3 levels
• Few or no signs or symptoms of hypothyroidism
McDermott MT, et al. J Clin Endocrinol Metab. 2001;86:4585-4590.
Braverman LE, Utiger RD, eds. The Thyroid: A Fundamental and Clinical Text. 8th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 2000;1001.
22
Populations at Risk for Mild Thyroid Failure
• Women• Prior history of Graves disease or
postpartum thyroid dysfunction• Elderly• Other autoimmune disease• Family history of
– Thyroid disease– Pernicious anemia– Type 1 Diabetes mellitus
Caraccio N, et al. J Clin Endocrinol Metab. 2002;87:1533-1538.
Carmel R, et al. Arch Intern Med. 1982;142:1465-1469.
Perros P, et al. Diabetes Med. 1995;12:622-627.
Mild Thyroid Failure May Be Confused With Other Disorders
• Hyperlipidemia
• Depression
• Gynecological conditions
• Aging
Canaris GJ, et al. Arch Intern Med. 2000;160:526-534.
Aldin V, et al. Am Fam Physician. 1998;57:776-780.
Nemeroff CB. J Clin Psychiatry. 1989;50(suppl):13-20.
Braverman LE, et al. Werner & Ingbar’s The Thyroid. A Fundamental and Clinical Text. 8th ed. 2000.
Mild Thyroid Failure May Increase Cardiovascular Disease Risk
• Mild thyroid failure has been evaluated as a cardiovascular risk factor– Increased (LDL-C) levels
– Reduced HDL
– Increased prevalence of aortic atherosclerosis
– Increased incidence of myocardial infarction
23
Primary Hypothyroidism Treatment Algorithm
TSH >4 IU/mL TSH <0.5 IU/mL
Initial Levothyroxine Dose
IncreaseLevothyroxine
Dose by12.5 to 25 g/d
Repeat TSH Test
6-8 Weeks
TSH 0.5- 2.0 IU/mLSymptoms Resolved
Measure TSH at 6 Months, Then Annually or
When Symptomatic
Continue Dose DecreaseLevothyroxine
Dose by12.5 to 25 g/d
Singer PA, et al. JAMA. 1995;273:808-812.
Demers LM, Spencer CA, eds. The National Academy of Clinical Biochemistry Web site. Available at:
http://www.nacb.org/lmpg/thyroid_lmpg.stm. Accessed July 1, 2003.
< 50 yrs: 25-50IU/mL
Half that in elderly
Hypothyroidism (Treatment)
Synthroid (LT4)
• 80% of PO dose is absorbed
• The main absorptive sites proximal and mid-jejunum.
• Food can ↓ LT4 absorption up to 40-50%. .
• T-1/2 LT4 is 7 days – can be given weekly in non compliant pt’s.
• Target: TSH 1.0-2.5 mU/L
Factors That May Reduce Levothyroxine Effectiveness
• Malabsorption Syndromes– Postjejunoileal 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 T4to 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.
24
T3 Replacement
• Yeah or nay?
• Triiodothyronine (Cytomel) 25 mcg (fast)
• Liotrix (Thyrolar) – 1 unit 12.5 mcg T3/ 50 mcg t4– Dosing consideration
Drug →Thyroid Tablets,
USP(Armour®
Thyroid)
Liotrix Tablets, USP
(Thyrolar™a)
LiothronineTablets, USP(Cytomel®b)
Levothyroxine Tablets, USP(Unithroid® c, Levoxyl® d,
Levothroid® e, Synthroid® f)
Approx. Dose Equivalent
1/4 grain (15 mg) 1/4 25 mcg (.025 mg)
Approx. Dose Equivalent
1/2 grain (30 mg) 1/2 12.5 mcg 50 mcg (.05 mg)
Approx. Dose Equivalent
1 grain (60 mg) 1 25 mcg 100 mcg ( .1 mg)
Approx. Dose Equivalent
1 1/2 grains (90 mg) 1 1/2 37.5 mcg 150 mcg (.15 mg)
Approx. Dose Equivalent
2 grains(120 mg) 2 50 mcg 200 mcg (.2 mg)
Approx. Dose Equivalent
3grains (180 mg) 3 75 mcg 300 mcg (.3 mg)
Dessicated Armour Thyroid
The basic "rule of thumb" in converting thyroid doses:
100 mcg of T4 is roughly equivalent to 25 mcg of T3, or 1 grain (60 mg) of desiccated thyroid
25
Case 1A 75 yo woman c/o “slowing down” & feeling a “little
forgetful.” She has constipation. BP 156/88; HR 62 regular; Physical exam normal for age:
LAB: TSH 9.0 (0.5-4.5 mU/L) FT4 1.1 (0.8-1.8 ng/dL), normal chemistry. Lipids not done
Which of the following actions would be most appropriate?A. Initiate treatment of levothyroxine 25 mcg/day &
recheck TSH in 6 weeks.B. Check lipid profile and start her on treatment if her LDL
is high.C. Check FT3, if low initiate therapy with levothyroxine.D. Check anti-TPO, and repeat TSH & FT4 in 2 – 6 weeks.
Case 2A 60 yo male with history htn, dm type 2, and
hyperlipidemia.MEDS: lisinopril, HCTZ, glipizide XL, and simvastatin. VS: 98.5, HR 98 (reg), resp rate 18, BP 118/78Phys exam is unremarkable. LABS: TSH 0.18 (0.45 – 5.0 mU/L), FT4 1.6 (0.8 – 1.8
ng/dL), FT3 3.5 (1.5-7.0 pmol/L). Chem panel/lipids normal. EKG is also normal
Which of the following statements would be appropriate?A. He has subclinical hypothyroidism with increased risk of develop
osteosporosis & atrial fibrillation so start treatment.B. Check anti-TPO. If it’s positive he will likely develop Graves’
disease in the future.C. He should have thyroid ultrasound, and start ATD.D. He should have a repeat TSH and FT4 in 3 – 6 weeks along with
anti-TPO.
Postpartum Thyroiditis
• Postpartum thyroiditis (PPT) reportedly affects 4-10% of women.
• PPT is an autoimmune thyroid disease that occurs during the first year after delivery.
• Will develop transient hyper- or hypothyroidism.
26
A word about goiters---seen in people with hyper-, hypo-, and euthyroid
References
• https://www.aace.com/files/hypo-hyper.pdf
• Burman KD. What Is the Clinical Importance of Subclinical Hyperthyroidism? Arch Intern Med. 2012;172(10):809-810. doi:10.1001
• .LeBeau SO, Mandel SJ. Thyroid disorders during pregnancy. Endocrinol Metab Clin North Am. Mar 2006;35(1):117-136, vii
• Rosario PW, Bessa B, Valadao MM, et al. Natural history of mild subclinical hypothyroidism: prognostic value of ultrasound. Thyroid. Jan 2009;19(1):9-12.
• The Endocrine Society. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline. National Guideline Clearinghouse. Available at http://guideline.gov/content.aspx?id=11283. Accessed April 24, 2009
• http://thyroidguidelines.net
• Wartofsky L. Myxedema coma. Endocrinol Metab Clin North Am. Dec 2006;35(4):687-698
• Zamfirescu I, Carlson HE. Absorption of levothyroxine when coadministered with various calcium formulations. Thyroid. May 2011;21(5):483-6.
SMILE……
I’M DONE!!