Subclinical hypothyroidism: Difference between revisions

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===Antithyroid peroxidase antibodies===
===Antithyroid peroxidase antibodies===
Antithyroid peroxidase (also called antithyroid microsomal) antibodies my help predict progression to overt hypothyroidism.<ref name="pmid15472181">{{cite journal| author=Díez JJ, Iglesias P| title=Spontaneous subclinical hypothyroidism in patients older than 55 years: an analysis of natural course and risk factors for the development of overt thyroid failure. | journal=J Clin Endocrinol Metab | year= 2004 | volume= 89 | issue= 10 | pages= 4890-7 | pmid=15472181 | doi=10.1210/jc.2003-032061 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15472181  }} </ref>  
Antithyroid peroxidase (also called antithyroid microsomal) antibodies my help predict progression to overt hypothyroidism.<ref name="pmid20097710">{{cite journal| author=Walsh JP, Bremner AP, Feddema P, Leedman PJ, Brown SJ, O'Leary P| title=Thyrotropin and thyroid antibodies as predictors of hypothyroidism: a 13-year, longitudinal study of a community-based cohort using current immunoassay techniques. | journal=J Clin Endocrinol Metab | year= 2010 | volume= 95 | issue= 3 | pages= 1095-104 | pmid=20097710 | doi=10.1210/jc.2009-1977 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20097710  }} </ref><ref name="pmid18270254">{{cite journal| author=Li Y, Teng D, Shan Z, Teng X, Guan H, Yu X et al.| title=Antithyroperoxidase and antithyroglobulin antibodies in a five-year follow-up survey of populations with different iodine intakes. | journal=J Clin Endocrinol Metab | year= 2008 | volume= 93 | issue= 5 | pages= 1751-7 | pmid=18270254 | doi=10.1210/jc.2007-2368 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18270254  }} </ref><ref name="pmid15472181">{{cite journal| author=Díez JJ, Iglesias P| title=Spontaneous subclinical hypothyroidism in patients older than 55 years: an analysis of natural course and risk factors for the development of overt thyroid failure. | journal=J Clin Endocrinol Metab | year= 2004 | volume= 89 | issue= 10 | pages= 4890-7 | pmid=15472181 | doi=10.1210/jc.2003-032061 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15472181  }} </ref>


Diagnostic accuracy for predicting over [[hypothyroidism]] has been reported.
Diagnostic accuracy for predicting over [[hypothyroidism]] has been reported.


Diez et al found that antibodies were significant predictors, but ''not'' after controlling for initial [[thyrotropin]] level. <ref name="pmid15472181">{{cite journal|  author=Díez JJ, Iglesias P| title=Spontaneous subclinical  hypothyroidism in patients older than 55 years: an analysis of natural  course and risk factors for the development of overt thyroid failure. |  journal=J Clin Endocrinol Metab | year= 2004 | volume= 89 | issue= 10 |  pages= 4890-7 | pmid=15472181 | doi=10.1210/jc.2003-032061 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15472181  }} </ref>
Diez et al found that antibodies > 20 U/ml were significant predictors of hypothyrodism after 3.5 years of follow-up in which 29% developed overt hypothyroidism, but ''not'' after controlling for initial [[thyrotropin]] level. <ref name="pmid15472181">{{cite journal|  author=Díez JJ, Iglesias P| title=Spontaneous subclinical  hypothyroidism in patients older than 55 years: an analysis of natural  course and risk factors for the development of overt thyroid failure. |  journal=J Clin Endocrinol Metab | year= 2004 | volume= 89 | issue= 10 |  pages= 4890-7 | pmid=15472181 | doi=10.1210/jc.2003-032061 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15472181  }} </ref>
* Sensitivity 93%
* Sensitivity 93%
* Specificity 30%
Walsh et al found that 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.<ref  name="pmid20097710">{{cite journal| author=Walsh JP, Bremner AP,  Feddema P, Leedman PJ, Brown SJ, O'Leary P| title=Thyrotropin and  thyroid antibodies as predictors of hypothyroidism: a 13-year,  longitudinal study of a community-based cohort using current immunoassay  techniques. | journal=J Clin Endocrinol Metab | year= 2010 | volume= 95  | issue= 3 | pages= 1095-104 | pmid=20097710 | doi=10.1210/jc.2009-1977  | pmc= |  url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20097710  }} </ref>
* Sensitivity 84%
* Specificity 30%
* Specificity 30%



Revision as of 08:26, 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 antibodies > 20 U/ml were significant predictors of hypothyrodism after 3.5 years of follow-up in which 29% developed overt hypothyroidism, but not after controlling for initial thyrotropin level. [6]

  • Sensitivity 93%
  • Specificity 30%

Walsh et al found that 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%

Screening

The US Preventive Services Task Force states:[7]

"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. 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]