Subclinical hypothyroidism: Difference between revisions

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imported>Robert Badgett
imported>Robert Badgett
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==Treatment==
==Treatment==
"In current RCTs, levothyroxine  replacement therapy for subclinical hypothyroidism did not result in  improved survival or decreased cardiovascular morbidity" according to a [[meta-analysis]] by the [[Cochrane Collaboration]]. <ref  name="pmid17636722">{{cite journal| author=Villar HC, Saconato H,  Valente O, Atallah AN| title=Thyroid hormone replacement for subclinical  hypothyroidism. | journal=Cochrane Database Syst Rev | year= 2007 |  volume=  | issue= 3 | pages= CD003419 | pmid=17636722 |  doi=10.1002/14651858.CD003419.pub2 | pmc= | url= }}  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18170994  Review in: ACP J Club. 2008 Jan-Feb;148(1):7]  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18170993  Review in: ACP J Club. 2008 Jan-Feb;148(1):6]  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18234930  Review in: Evid Based Med. 2008 Feb;13(1):22] </ref> Subsequent [[randomized controlled trial]]s have been positive<ref name="pmid17299073">{{cite journal| author=Razvi S, Ingoe L, Keeka G, Oates C, McMillan C, Weaver JU| title=The beneficial effect of L-thyroxine on cardiovascular risk factors, endothelial function, and quality of life in subclinical hypothyroidism: randomized, crossover trial. | journal=J Clin Endocrinol Metab | year= 2007 | volume= 92 | issue= 5 | pages= 1715-23 | pmid=17299073 | doi=10.1210/jc.2006-1869 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17299073  }} </ref> and negative<ref name="pmid20501682">{{cite journal| author=Parle J, Roberts L, Wilson S, Pattison H, Roalfe A, Haque MS et al.| title=A randomized controlled trial of the effect of thyroxine replacement on cognitive function in community-living elderly subjects with subclinical hypothyroidism: the Birmingham Elderly Thyroid study. | journal=J Clin Endocrinol Metab | year= 2010 | volume= 95 | issue= 8 | pages= 3623-32 | pmid=20501682 | doi=10.1210/jc.2009-2571 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20501682  }} </ref>.
"In current RCTs, levothyroxine  replacement therapy for subclinical hypothyroidism did not result in  improved survival or decreased cardiovascular morbidity" according to a [[meta-analysis]] by the [[Cochrane Collaboration]]. <ref  name="pmid17636722">{{cite journal| author=Villar HC, Saconato H,  Valente O, Atallah AN| title=Thyroid hormone replacement for subclinical  hypothyroidism. | journal=Cochrane Database Syst Rev | year= 2007 |  volume=  | issue= 3 | pages= CD003419 | pmid=17636722 |  doi=10.1002/14651858.CD003419.pub2 | pmc= | url= }}  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18170994  Review in: ACP J Club. 2008 Jan-Feb;148(1):7]  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18170993  Review in: ACP J Club. 2008 Jan-Feb;148(1):6]  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18234930  Review in: Evid Based Med. 2008 Feb;13(1):22] </ref> Subsequent [[randomized controlled trial]]s have been positive using 100 microg T4 orally per day<ref name="pmid17299073">{{cite journal| author=Razvi S, Ingoe L, Keeka G, Oates C, McMillan C, Weaver JU| title=The beneficial effect of L-thyroxine on cardiovascular risk factors, endothelial function, and quality of life in subclinical hypothyroidism: randomized, crossover trial. | journal=J Clin Endocrinol Metab | year= 2007 | volume= 92 | issue= 5 | pages= 1715-23 | pmid=17299073 | doi=10.1210/jc.2006-1869 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17299073  }} </ref> and negative using 25 microg T4 orally per day<ref name="pmid20501682">{{cite journal| author=Parle J, Roberts L, Wilson S, Pattison H, Roalfe A, Haque MS et al.| title=A randomized controlled trial of the effect of thyroxine replacement on cognitive function in community-living elderly subjects with subclinical hypothyroidism: the Birmingham Elderly Thyroid study. | journal=J Clin Endocrinol Metab | year= 2010 | volume= 95 | issue= 8 | pages= 3623-32 | pmid=20501682 | doi=10.1210/jc.2009-2571 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20501682  }} </ref>.


==Screening==
==Screening==

Revision as of 09:20, 19 April 2012

In medicine, subclinical hypothyroidism is an elevated thyrotropin (TSH) concentration can maintain a normal or near normal thyroxine (T4) concentration.[1][2]

Prognosis

Thyrotropin level

Evolution of thyrotropin values over 5 years.[3]
  Follow-up TSH value
TSH > 10 TSH < 10
TSH > 10 35% 64%
TSH 5.5 - 10 3% 97%

The thyrotropin level helps predict progression to overt hypothyroidism.[3]

Antithyroid peroxidase antibodies

Antithyroid peroxidase (also called antithyroid microsomal) antibodies my help predict progression to overt hypothyroidism.[4][5][6]

Diagnostic accuracy for predicting over hypothyroidism has been reported.

Diez et al found that among patients with TSH > 5, antibodies > 20 U/ml were significant predictors of hypothyrodism after 3.5 years of follow-up in which 26% developed overt hypothyroidism, but not after controlling for initial thyrotropin level.[6]

  • Sensitivity 93%
  • Specificity 30%
  • Positive predictive value 32%
  • Negative predictive value 92%

Walsh et al found that among patients with TSH> 4, antibodies > 35 U/ml were significant predictors of hypothyrodism after 13 years of follow-up in which 31% developed overt hypothyroidism, but not after controlling for initial thyrotropin level.[4]

  • Sensitivity 84%
  • Specificity 30%
  • Positive predictive value 60%
  • Negative predictive value 60%

Treatment

"In current RCTs, levothyroxine replacement therapy for subclinical hypothyroidism did not result in improved survival or decreased cardiovascular morbidity" according to a meta-analysis by the Cochrane Collaboration. [7] Subsequent randomized controlled trials have been positive using 100 microg T4 orally per day[8] and negative using 25 microg T4 orally per day[9].

Screening

The US Preventive Services Task Force states:[10]

"t is uncertain whether treatment will improve quality of life in otherwise healthy patients who have abnormal TSH levels and normal free thyroxine levels."

References

  1. ↑ Surks MI, Ortiz E, Daniels GH, Sawin CT, Col NF, Cobin RH et al. (2004). "Subclinical thyroid disease: scientific review and guidelines for diagnosis and management.". JAMA 291 (2): 228-38. DOI:10.1001/jama.291.2.228. PMID 14722150. Research Blogging.
  2. ↑ Cooper DS, Biondi B (2012). "Subclinical thyroid disease.". Lancet 379 (9821): 1142-54. DOI:10.1016/S0140-6736(11)60276-6. PMID 22273398. Research Blogging.
  3. ↑ 3.0 3.1 Meyerovitch J, Rotman-Pikielny P, Sherf M, Battat E, Levy Y, Surks MI (2007). "Serum thyrotropin measurements in the community: five-year follow-up in a large network of primary care physicians.". Arch Intern Med 167 (14): 1533-8. DOI:10.1001/archinte.167.14.1533. PMID 17646608. Research Blogging. Cite error: Invalid <ref> tag; name "pmid17646608" defined multiple times with different content
  4. ↑ 4.0 4.1 Walsh JP, Bremner AP, Feddema P, Leedman PJ, Brown SJ, O'Leary P (2010). "Thyrotropin and thyroid antibodies as predictors of hypothyroidism: a 13-year, longitudinal study of a community-based cohort using current immunoassay techniques.". J Clin Endocrinol Metab 95 (3): 1095-104. DOI:10.1210/jc.2009-1977. PMID 20097710. Research Blogging. Cite error: Invalid <ref> tag; name "pmid20097710" defined multiple times with different content
  5. ↑ Li Y, Teng D, Shan Z, Teng X, Guan H, Yu X et al. (2008). "Antithyroperoxidase and antithyroglobulin antibodies in a five-year follow-up survey of populations with different iodine intakes.". J Clin Endocrinol Metab 93 (5): 1751-7. DOI:10.1210/jc.2007-2368. PMID 18270254. Research Blogging.
  6. ↑ 6.0 6.1 Díez JJ, Iglesias P (2004). "Spontaneous subclinical hypothyroidism in patients older than 55 years: an analysis of natural course and risk factors for the development of overt thyroid failure.". J Clin Endocrinol Metab 89 (10): 4890-7. DOI:10.1210/jc.2003-032061. PMID 15472181. Research Blogging. Cite error: Invalid <ref> tag; name "pmid15472181" defined multiple times with different content
  7. ↑ Villar HC, Saconato H, Valente O, Atallah AN (2007). "Thyroid hormone replacement for subclinical hypothyroidism.". Cochrane Database Syst Rev (3): CD003419. DOI:10.1002/14651858.CD003419.pub2. PMID 17636722. Research Blogging. Review in: ACP J Club. 2008 Jan-Feb;148(1):7 Review in: ACP J Club. 2008 Jan-Feb;148(1):6 Review in: Evid Based Med. 2008 Feb;13(1):22
  8. ↑ Razvi S, Ingoe L, Keeka G, Oates C, McMillan C, Weaver JU (2007). "The beneficial effect of L-thyroxine on cardiovascular risk factors, endothelial function, and quality of life in subclinical hypothyroidism: randomized, crossover trial.". J Clin Endocrinol Metab 92 (5): 1715-23. DOI:10.1210/jc.2006-1869. PMID 17299073. Research Blogging.
  9. ↑ Parle J, Roberts L, Wilson S, Pattison H, Roalfe A, Haque MS et al. (2010). "A randomized controlled trial of the effect of thyroxine replacement on cognitive function in community-living elderly subjects with subclinical hypothyroidism: the Birmingham Elderly Thyroid study.". J Clin Endocrinol Metab 95 (8): 3623-32. DOI:10.1210/jc.2009-2571. PMID 20501682. Research Blogging.
  10. ↑ Helfand M, U.S. Preventive Services Task Force (2004). "Screening for subclinical thyroid dysfunction in nonpregnant adults: a summary of the evidence for the U.S. Preventive Services Task Force.". Ann Intern Med 140 (2): 128-41. PMID 14734337. [e]
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