Subclinical Hypothyroidism: Point/Counterpoint: Treat or Not? AACE Annual Congress Nashville, Tennessee May 14, 2015 Moderator: Peter A. Singer Discussants: Jeffrey R. Garber, Paul W. Ladenson
Subclinical Hypothyroidism • PubMed 5/2015 • 2538 articles! • Why??
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None of the participants have any conflicts to disclose.
Case 1 • HPI: 60-year-old woman has been seen by her PCP to evaluate fatigue, difficulty losing weight, and decreased short-term memory. Lab testing showed serum TSH 6.4 mU/L and FT4 1.0 ng/dL, prompting referral to you. • PE: Tired appearing. Wt 174 lbs, Ht 66”, BMI 29.7 BP 126/82 mm Hg, P 76/min. Thyroid: normal. • Other laboratory data: • TPO antibody 34 IU/mL (normal age 65
Health Aging Study 2005
No
Mean age 75; ↑ CHF risk
Leiden Plus 2004
No
Age >85
Prospective Studies
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Subclinical Hypothyroidism & Cardiovascular Events
Meta Analyses Study
No. of Studies & Patients
Singh, et al. Int J Cardiol, 2008
6 / 13,267
Higher CHD prevalence 1.53 (1.311.79), incidence 1.19 (1.02-1.38), and mortality, 1.28 (1.02-1.60)
Ochs, et al. Ann Int Med, 2008
10 / 14,449
Higher CHD risk ratio for all 1.20 (95%CI, 0.97-1.49) and especially for 70 Years Old L-T4 treated
Untreated
Adjusted HR, 0.99; 95% CI, 0.59-1.33 = 0.56 Adjusted HR,P0.61; 95% CI, 0.39-0.95
Razvi S, et al. Arch Intern Med. April 23, 2012
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Subclinical Hypothyroidism
Potential Harms of Detection & Rx • False-positive results (i.e, spontaneous reversibility) • Psychological effects of disease labeling • Overtreatment and its impact on the heart and skeleton • [Cost]
Treatment of Hypothyroidism
Suboptimal Therapy Is Common 30%
Excessive Thyroxine Therapy
20%
Inadequate Thyroxine Therapy
10%
10%
21% 14%
18% 20% 30%
22%
18%
18%
15%
27% Ross, 1990
Parle, 1993
Canaris, 2000
Hallowell, 2002
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Thyrotoxic Atrial Fibrillation
Incidence in Subclinical Hyperthyroidism Incidence of Arterial Fibrillation (%)
30
40% were thyroid hormone-treated
25 20
TSH 50 years with an incidental finding suggestive of symptomatic thyroid disease should be evaluated.
ACP British Thyroid Assoc Assoc Clin Biochem (UK) Royal College Physicians
2006
Against routine thyroid function screening in healthy adults
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AACE RESPONSE • We agree with the USPSTF that strong data do not exist to justify screening non-pregnant adult populations for thyroid disease. However the data called for by the USPSTF is unlikely forthcoming [19] and thyroid dysfunction can be readily diagnosed and treated in a safe and cost effective manner. Accordingly, in the interim thyroid dysfunction should be considered when evaluating many of the non-specific complaints that physicians face daily [5] particularly in those persons most likely to have thyroid disease who benefit from treatment.
AACE RESPONSE • ATA/AACE has recommended aggressive case finding (ACF) rather than general population screening for those with specific clinical features making it more likely to have thyroid dysfunction and to benefit from diagnosis[5]. For hypothyroidism these include: family history of thyroid disease, autoimmune disorders, anemias, chromosomal disorders, prior neck radiation or thyroid surgery, hyperprolactinemia, taking amiodarone, lithium, tyrosine kinase inhibitors, interferon α and interleukin-2
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