Subclinical hypothyroidism: Difference between revisions
Jump to navigation
Jump to search
imported>Robert Badgett |
Pat Palmer (talk | contribs) (resolving reference issues) |
||
| (7 intermediate revisions by 3 users not shown) | |||
| Line 1: | Line 1: | ||
In [[medicine]], '''subclinical hypothyroidism''' is an elevated | {{subpages}} | ||
{{TOC|right}} | |||
In [[medicine]], '''subclinical hypothyroidism''' is an elevated ''thyrotropin'' (a.k.a. thyroid stimulating hormone, or TSH) concentration can maintain a normal or near normal [[thyroxine ]](T4) concentration.<ref name="pmid14722150">{{cite journal| author=Surks MI, Ortiz E, Daniels GH, Sawin CT, Col NF, Cobin RH et al.| title=Subclinical thyroid disease: scientific review and guidelines for diagnosis and management. | journal=JAMA | year= 2004 | volume= 291 | issue= 2 | pages= 228-38 | pmid=14722150 | doi=10.1001/jama.291.2.228 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14722150 }} </ref><ref name="pmid22273398">{{cite journal| author=Cooper DS, Biondi B| title=Subclinical thyroid disease. | journal=Lancet | year= 2012 | volume= 379 | issue= 9821 | pages= 1142-54 | pmid=22273398 | doi=10.1016/S0140-6736(11)60276-6 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22273398 }} </ref> | |||
==Prognosis== | ==Prognosis== | ||
"Subclinical hypothyroidism is associated with an increased risk of CHD events and CHD mortality in those with higher TSH levels, particularly in those with a TSH concentration of 10 mIU/L or greater" according to a individual patient data [[meta-analysis]]. <ref name="pmid20858880">{{cite journal| author=Rodondi N, den Elzen WP, Bauer DC, Cappola AR, Razvi S, Walsh JP et al.| title=Subclinical hypothyroidism and the risk of coronary heart disease and mortality. | journal=JAMA | year= 2010 | volume= 304 | issue= 12 | pages= 1365-74 | pmid=20858880 | doi=10.1001/jama.2010.1361 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20858880 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21169625 Review in: Evid Based Med. 2011 Feb;16(1):31-2] </ref> | "Subclinical hypothyroidism is associated with an increased risk of congenital heart disease (CHD) events and CHD mortality in those with higher TSH levels, particularly in those with a TSH concentration of 10 mIU/L or greater" according to a individual patient data [[meta-analysis]]. <ref name="pmid20858880">{{cite journal| author=Rodondi N, den Elzen WP, Bauer DC, Cappola AR, Razvi S, Walsh JP et al.| title=Subclinical hypothyroidism and the risk of coronary heart disease and mortality. | journal=JAMA | year= 2010 | volume= 304 | issue= 12 | pages= 1365-74 | pmid=20858880 | doi=10.1001/jama.2010.1361 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20858880 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21169625 Review in: Evid Based Med. 2011 Feb;16(1):31-2] </ref> | ||
==Thyrotropin level== | ==Thyrotropin level== | ||
| Line 18: | Line 20: | ||
|} | |} | ||
The thyrotropin level helps predict progression to overt [[hypothyroidism]].<ref name="pmid17646608" | The thyrotropin level helps predict progression to overt [[hypothyroidism]].<ref name="pmid17646608"/> | ||
===Antithyroid peroxidase antibodies=== | ===Antithyroid peroxidase antibodies=== | ||
| Line 25: | Line 27: | ||
Diagnostic accuracy for predicting over [[hypothyroidism]] has been reported. | 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.<ref name="pmid15472181" | 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.<ref name="pmid15472181"/> | ||
* Sensitivity 93% | * Sensitivity 93% | ||
* Specificity 30% | * Specificity 30% | ||
| Line 31: | Line 33: | ||
* Negative predictive value 92% | * 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.<ref name="pmid20097710" | 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.<ref name="pmid20097710"/> | ||
* Sensitivity 84% | * Sensitivity 84% | ||
* Specificity 30% | * Specificity 30% | ||
| Line 38: | Line 40: | ||
==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 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>. | "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>. | |||
Subsequent observational studies have<ref name="pmid22529180">{{cite journal| author=Razvi S, Weaver JU, Butler TJ, Pearce SH| title=Levothyroxine Treatment of Subclinical Hypothyroidism, Fatal and Nonfatal Cardiovascular Events, and Mortality. | journal=Arch Intern Med | year= 2012 | volume= | issue= | pages= | pmid=22529180 | doi=10.1001/archinternmed.2012.1159 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22529180 }} </ref> and have not<ref name="pmid20150579">{{cite journal| author=Razvi S, Weaver JU, Vanderpump MP, Pearce SH| title=The incidence of ischemic heart disease and mortality in people with subclinical hypothyroidism: reanalysis of the Whickham Survey cohort. | journal=J Clin Endocrinol Metab | year= 2010 | volume= 95 | issue= 4 | pages= 1734-40 | pmid=20150579 | doi=10.1210/jc.2009-1749 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20150579 }} </ref> shown a relationship between untreated subclinical hypothyroidism and ischemic heart disease. | |||
[[Clinical practice guideline]]s guide management.<ref name="pmid22967432">{{cite journal| author=Garber JR, Cobin RH, Gharib H, Hennessey JV, Klein I, Mechanick JI et al.| title=Clinical Practice Guidelines for Hypothyroidism in Adults: Co-sponsored by American Association of Clinical Endocrinologists and the American Thyroid Association. | journal=Endocr Pract | year= 2012 | volume= | issue= | pages= 1-207 | pmid=22967432 | doi=10.4158/EP12280.GL | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22967432 }} </ref> | [[Clinical practice guideline]]s guide management.<ref name="pmid22967432">{{cite journal| author=Garber JR, Cobin RH, Gharib H, Hennessey JV, Klein I, Mechanick JI et al.| title=Clinical Practice Guidelines for Hypothyroidism in Adults: Co-sponsored by American Association of Clinical Endocrinologists and the American Thyroid Association. | journal=Endocr Pract | year= 2012 | volume= | issue= | pages= 1-207 | pmid=22967432 | doi=10.4158/EP12280.GL | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22967432 }} </ref> | ||
| Line 45: | Line 51: | ||
==Screening== | ==Screening== | ||
The [[ | The [[U.S. Preventive Services Task Force]] states:<ref name="pmid14734337">{{cite journal| author=Helfand M, U.S. Preventive Services Task Force| title=Screening for subclinical thyroid dysfunction in nonpregnant adults: a summary of the evidence for the U.S. Preventive Services Task Force. | journal=Ann Intern Med | year= 2004 | volume= 140 | issue= 2 | pages= 128-41 | pmid=14734337 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14734337 }} </ref> | ||
:"t is uncertain whether treatment will improve quality of life in otherwise healthy patients who have abnormal TSH levels and normal free thyroxine levels." | :"t is uncertain whether treatment will improve quality of life in otherwise healthy patients who have abnormal TSH levels and normal free thyroxine levels." | ||
| Line 52: | Line 58: | ||
==References== | ==References== | ||
<small> | |||
<references/> | <references/> | ||
</small> | |||
Latest revision as of 09:18, 22 October 2024
In medicine, subclinical hypothyroidism is an elevated thyrotropin (a.k.a. thyroid stimulating hormone, or TSH) concentration can maintain a normal or near normal thyroxine (T4) concentration.[1][2]
Prognosis
"Subclinical hypothyroidism is associated with an increased risk of congenital heart disease (CHD) events and CHD mortality in those with higher TSH levels, particularly in those with a TSH concentration of 10 mIU/L or greater" according to a individual patient data meta-analysis. [3]
Thyrotropin level
| 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.[4]
Antithyroid peroxidase antibodies
Antithyroid peroxidase (also called antithyroid microsomal) antibodies my help predict progression to overt hypothyroidism.[5][6][7]
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.[7]
- 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.[5]
- 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. [8]
Subsequent randomized controlled trials have been positive using 100 microg T4 orally per day[9] and negative using 25 microg T4 orally per day[10].
Subsequent observational studies have[11] and have not[12] shown a relationship between untreated subclinical hypothyroidism and ischemic heart disease.
Clinical practice guidelines guide management.[13]
Prior consensus statements conflict with some recommending[14][15][16] and others not[1] recommending treatment.[17]
Screening
The U.S. Preventive Services Task Force states:[18]
- "t is uncertain whether treatment will improve quality of life in otherwise healthy patients who have abnormal TSH levels and normal free thyroxine levels."
The Institute of Medicine recommends against screening.[19]
References
- ↑ 1.0 1.1 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.
- ↑ 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.
- ↑ Rodondi N, den Elzen WP, Bauer DC, Cappola AR, Razvi S, Walsh JP et al. (2010). "Subclinical hypothyroidism and the risk of coronary heart disease and mortality.". JAMA 304 (12): 1365-74. DOI:10.1001/jama.2010.1361. PMID 20858880. Research Blogging. Review in: Evid Based Med. 2011 Feb;16(1):31-2
- ↑ 4.0 4.1 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.
- ↑ 5.0 5.1 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.
- ↑ 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.
- ↑ 7.0 7.1 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.
- ↑ 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
- ↑ 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.
- ↑ 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.
- ↑ Razvi S, Weaver JU, Butler TJ, Pearce SH (2012). "Levothyroxine Treatment of Subclinical Hypothyroidism, Fatal and Nonfatal Cardiovascular Events, and Mortality.". Arch Intern Med. DOI:10.1001/archinternmed.2012.1159. PMID 22529180. Research Blogging.
- ↑ Razvi S, Weaver JU, Vanderpump MP, Pearce SH (2010). "The incidence of ischemic heart disease and mortality in people with subclinical hypothyroidism: reanalysis of the Whickham Survey cohort.". J Clin Endocrinol Metab 95 (4): 1734-40. DOI:10.1210/jc.2009-1749. PMID 20150579. Research Blogging.
- ↑ Garber JR, Cobin RH, Gharib H, Hennessey JV, Klein I, Mechanick JI et al. (2012). "Clinical Practice Guidelines for Hypothyroidism in Adults: Co-sponsored by American Association of Clinical Endocrinologists and the American Thyroid Association.". Endocr Pract: 1-207. DOI:10.4158/EP12280.GL. PMID 22967432. Research Blogging.
- ↑ Gharib H, Tuttle RM, Baskin HJ, Fish LH, Singer PA, McDermott MT et al. (2005). "Consensus Statement #1: Subclinical thyroid dysfunction: a joint statement on management from the American Association of Clinical Endocrinologists, the American Thyroid Association, and The Endocrine Society.". Thyroid 15 (1): 24-8; response 32-3. DOI:10.1089/thy.2005.15.24. PMID 15687817. Research Blogging.
- ↑ Gharib H, Tuttle RM, Baskin HJ, Fish LH, Singer PA, McDermott MT et al. (2004). "Subclinical thyroid dysfunction: a joint statement on management from the American Association of Clinical Endocrinologists, the American Thyroid Association, and the Endocrine Society.". Endocr Pract 10 (6): 497-501. PMID 16033723. [e]
- ↑ Gharib H, Tuttle RM, Baskin HJ, Fish LH, Singer PA, McDermott MT (2005). "Subclinical thyroid dysfunction: a joint statement on management from the American Association of Clinical Endocrinologists, the American Thyroid Association, and the Endocrine Society.". J Clin Endocrinol Metab 90 (1): 581-5; discussion 586-7. DOI:10.1210/jc.2004-1231. PMID 15643019. Research Blogging.
- ↑ Ringel MD, Mazzaferri EL (2005). "Subclinical thyroid dysfunction--can there be a consensus about the consensus?". J Clin Endocrinol Metab 90 (1): 588-90. DOI:10.1210/jc.2004-2173. PMID 15643021. Research Blogging.
- ↑ 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]
- ↑ Institute of Medicine (2003). Medicare Coverage of Routine Screening for Thyroid Dysfunction