@article {1231, title = {Subclinical hypothyroidism and the risk of coronary heart disease and mortality.}, journal = {JAMA}, volume = {304}, year = {2010}, month = {2010 Sep 22}, pages = {1365-74}, abstract = {

CONTEXT: Data regarding the association between subclinical hypothyroidism and cardiovascular disease outcomes are conflicting among large prospective cohort studies. This might reflect differences in participants{\textquoteright} age, sex, thyroid-stimulating hormone (TSH) levels, or preexisting cardiovascular disease.

OBJECTIVE: To assess the risks of coronary heart disease (CHD) and total mortality for adults with subclinical hypothyroidism.

DATA SOURCES AND STUDY SELECTION: The databases of MEDLINE and EMBASE (1950 to May 31, 2010) were searched without language restrictions for prospective cohort studies with baseline thyroid function and subsequent CHD events, CHD mortality, and total mortality. The reference lists of retrieved articles also were searched.

DATA EXTRACTION: Individual data on 55,287 participants with 542,494 person-years of follow-up between 1972 and 2007 were supplied from 11 prospective cohorts in the United States, Europe, Australia, Brazil, and Japan. The risk of CHD events was examined in 25,977 participants from 7 cohorts with available data. Euthyroidism was defined as a TSH level of 0.50 to 4.49 mIU/L. Subclinical hypothyroidism was defined as a TSH level of 4.5 to 19.9 mIU/L with normal thyroxine concentrations.

RESULTS: Among 55,287 adults, 3450 had subclinical hypothyroidism (6.2\%) and 51,837 had euthyroidism. During follow-up, 9664 participants died (2168 of CHD), and 4470 participants had CHD events (among 7 studies). The risk of CHD events and CHD mortality increased with higher TSH concentrations. In age- and sex-adjusted analyses, the hazard ratio (HR) for CHD events was 1.00 (95\% confidence interval [CI], 0.86-1.18) for a TSH level of 4.5 to 6.9 mIU/L (20.3 vs 20.3/1000 person-years for participants with euthyroidism), 1.17 (95\% CI, 0.96-1.43) for a TSH level of 7.0 to 9.9 mIU/L (23.8/1000 person-years), and 1.89 (95\% CI, 1.28-2.80) for a TSH level of 10 to 19.9 mIU/L (n = 70 events/235; 38.4/1000 person-years; P <.001 for trend). The corresponding HRs for CHD mortality were 1.09 (95\% CI, 0.91-1.30; 5.3 vs 4.9/1000 person-years for participants with euthyroidism), 1.42 (95\% CI, 1.03-1.95; 6.9/1000 person-years), and 1.58 (95\% CI, 1.10-2.27, n = 28 deaths/333; 7.7/1000 person-years; P = .005 for trend). Total mortality was not increased among participants with subclinical hypothyroidism. Results were similar after further adjustment for traditional cardiovascular risk factors. Risks did not significantly differ by age, sex, or preexisting cardiovascular disease.

CONCLUSIONS: 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.

}, keywords = {Adolescent, Adult, Aged, Aged, 80 and over, Coronary Disease, Female, Humans, Hypothyroidism, Male, Middle Aged, Mortality, Prospective Studies, Risk, Thyrotropin, Young Adult}, issn = {1538-3598}, doi = {10.1001/jama.2010.1361}, author = {Rodondi, Nicolas and den Elzen, Wendy P J and Bauer, Douglas C and Cappola, Anne R and Razvi, Salman and Walsh, John P and Asvold, Bj{\o}rn O and Iervasi, Giorgio and Imaizumi, Misa and Collet, Tinh-Hai and Bremner, Alexandra and Maisonneuve, Patrick and Sgarbi, Jos{\'e} A and Khaw, Kay-Tee and Vanderpump, Mark P J and Newman, Anne B and Cornuz, Jacques and Franklyn, Jayne A and Westendorp, Rudi G J and Vittinghoff, Eric and Gussekloo, Jacobijn} } @article {1545, title = {Subclinical hyperthyroidism and the risk of coronary heart disease and mortality.}, journal = {Arch Intern Med}, volume = {172}, year = {2012}, month = {2012 May 28}, pages = {799-809}, abstract = {

BACKGROUND: Data from prospective cohort studies regarding the association between subclinical hyperthyroidism and cardiovascular outcomes are conflicting.We aimed to assess the risks of total and coronary heart disease (CHD) mortality, CHD events, and atrial fibrillation (AF) associated with endogenous subclinical hyperthyroidism among all available large prospective cohorts.

METHODS: Individual data on 52 674 participants were pooled from 10 cohorts. Coronary heart disease events were analyzed in 22 437 participants from 6 cohorts with available data, and incident AF was analyzed in 8711 participants from 5 cohorts. Euthyroidism was defined as thyrotropin level between 0.45 and 4.49 mIU/L and endogenous subclinical hyperthyroidism as thyrotropin level lower than 0.45 mIU/L with normal free thyroxine levels, after excluding those receiving thyroid-altering medications.

RESULTS: Of 52 674 participants, 2188 (4.2\%) had subclinical hyperthyroidism. During follow-up, 8527 participants died (including 1896 from CHD), 3653 of 22 437 had CHD events, and 785 of 8711 developed AF. In age- and sex-adjusted analyses, subclinical hyperthyroidism was associated with increased total mortality (hazard ratio[HR], 1.24, 95\% CI, 1.06-1.46), CHD mortality (HR,1.29; 95\% CI, 1.02-1.62), CHD events (HR, 1.21; 95\%CI, 0.99-1.46), and AF (HR, 1.68; 95\% CI, 1.16-2.43).Risks did not differ significantly by age, sex, or preexisting cardiovascular disease and were similar after further adjustment for cardiovascular risk factors, with attributable risk of 14.5\% for total mortality to 41.5\% forAF in those with subclinical hyperthyroidism. Risks for CHD mortality and AF (but not other outcomes) were higher for thyrotropin level lower than 0.10 mIU/L compared with thyrotropin level between 0.10 and 0.44 mIU/L(for both, P value for trend, .03).

CONCLUSION: Endogenous subclinical hyperthyroidism is associated with increased risks of total, CHD mortality, and incident AF, with highest risks of CHD mortality and AF when thyrotropin level is lower than 0.10 mIU/L.

}, keywords = {Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Atrial Fibrillation, Cause of Death, Cohort Studies, Coronary Artery Disease, Female, Humans, Hyperthyroidism, Male, Middle Aged, Prognosis, Prospective Studies, Risk Assessment, Severity of Illness Index, Sex Distribution, Survival Analysis, Switzerland, Thyroid Function Tests, Thyrotropin, Young Adult}, issn = {1538-3679}, doi = {10.1001/archinternmed.2012.402}, author = {Collet, Tinh-Hai and Gussekloo, Jacobijn and Bauer, Douglas C and den Elzen, Wendy P J and Cappola, Anne R and Balmer, Philippe and Iervasi, Giorgio and Asvold, Bj{\o}rn O and Sgarbi, Jos{\'e} A and V{\"o}lzke, Henry and Gencer, Bari{\c s} and Maciel, Rui M B and Molinaro, Sabrina and Bremner, Alexandra and Luben, Robert N and Maisonneuve, Patrick and Cornuz, Jacques and Newman, Anne B and Khaw, Kay-Tee and Westendorp, Rudi G J and Franklyn, Jayne A and Vittinghoff, Eric and Walsh, John P and Rodondi, Nicolas} } @article {6294, title = {Identification of novel genetic Loci associated with thyroid peroxidase antibodies and clinical thyroid disease.}, journal = {PLoS Genet}, volume = {10}, year = {2014}, month = {2014 Feb}, pages = {e1004123}, abstract = {

Autoimmune thyroid diseases (AITD) are common, affecting 2-5\% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto{\textquoteright}s thyroiditis), as well as autoimmune hyperthyroidism (Graves{\textquoteright} disease). As the possible causative genes of TPOAbs and AITD remain largely unknown, we performed GWAS meta-analyses in 18,297 individuals for TPOAb-positivity (1769 TPOAb-positives and 16,528 TPOAb-negatives) and in 12,353 individuals for TPOAb serum levels, with replication in 8,990 individuals. Significant associations (P<5{\texttimes}10(-8)) were detected at TPO-rs11675434, ATXN2-rs653178, and BACH2-rs10944479 for TPOAb-positivity, and at TPO-rs11675434, MAGI3-rs1230666, and KALRN-rs2010099 for TPOAb levels. Individual and combined effects (genetic risk scores) of these variants on (subclinical) hypo- and hyperthyroidism, goiter and thyroid cancer were studied. Individuals with a high genetic risk score had, besides an increased risk of TPOAb-positivity (OR: 2.18, 95\% CI 1.68-2.81, P = 8.1{\texttimes}10(-8)), a higher risk of increased thyroid-stimulating hormone levels (OR: 1.51, 95\% CI 1.26-1.82, P = 2.9{\texttimes}10(-6)), as well as a decreased risk of goiter (OR: 0.77, 95\% CI 0.66-0.89, P = 6.5{\texttimes}10(-4)). The MAGI3 and BACH2 variants were associated with an increased risk of hyperthyroidism, which was replicated in an independent cohort of patients with Graves{\textquoteright} disease (OR: 1.37, 95\% CI 1.22-1.54, P = 1.2{\texttimes}10(-7) and OR: 1.25, 95\% CI 1.12-1.39, P = 6.2{\texttimes}10(-5)). The MAGI3 variant was also associated with an increased risk of hypothyroidism (OR: 1.57, 95\% CI 1.18-2.10, P = 1.9{\texttimes}10(-3)). This first GWAS meta-analysis for TPOAbs identified five newly associated loci, three of which were also associated with clinical thyroid disease. With these markers we identified a large subgroup in the general population with a substantially increased risk of TPOAbs. The results provide insight into why individuals with thyroid autoimmunity do or do not eventually develop thyroid disease, and these markers may therefore predict which TPOAb-positives are particularly at risk of developing clinical thyroid dysfunction.

}, keywords = {Autoantibodies, Genetic Loci, Genome-Wide Association Study, Graves Disease, Hashimoto Disease, Humans, Iodide Peroxidase, Risk Factors, Thyroiditis, Autoimmune, Thyrotropin}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1004123}, author = {Medici, Marco and Porcu, Eleonora and Pistis, Giorgio and Teumer, Alexander and Brown, Suzanne J and Jensen, Richard A and Rawal, Rajesh and Roef, Greet L and Plantinga, Theo S and Vermeulen, Sita H and Lahti, Jari and Simmonds, Matthew J and Husemoen, Lise Lotte N and Freathy, Rachel M and Shields, Beverley M and Pietzner, Diana and Nagy, Rebecca and Broer, Linda and Chaker, Layal and Korevaar, Tim I M and Plia, Maria Grazia and Sala, Cinzia and V{\"o}lker, Uwe and Richards, J Brent and Sweep, Fred C and Gieger, Christian and Corre, Tanguy and Kajantie, Eero and Thuesen, Betina and Taes, Youri E and Visser, W Edward and Hattersley, Andrew T and Kratzsch, J{\"u}rgen and Hamilton, Alexander and Li, Wei and Homuth, Georg and Lobina, Monia and Mariotti, Stefano and Soranzo, Nicole and Cocca, Massimiliano and Nauck, Matthias and Spielhagen, Christin and Ross, Alec and Arnold, Alice and van de Bunt, Martijn and Liyanarachchi, Sandya and Heier, Margit and Grabe, Hans J{\"o}rgen and Masciullo, Corrado and Galesloot, Tessel E and Lim, Ee M and Reischl, Eva and Leedman, Peter J and Lai, Sandra and Delitala, Alessandro and Bremner, Alexandra P and Philips, David I W and Beilby, John P and Mulas, Antonella and Vocale, Matteo and Abecasis, Goncalo and Forsen, Tom and James, Alan and Widen, Elisabeth and Hui, Jennie and Prokisch, Holger and Rietzschel, Ernst E and Palotie, Aarno and Feddema, Peter and Fletcher, Stephen J and Schramm, Katharina and Rotter, Jerome I and Kluttig, Alexander and Radke, D{\"o}rte and Traglia, Michela and Surdulescu, Gabriela L and He, Huiling and Franklyn, Jayne A and Tiller, Daniel and Vaidya, Bijay and De Meyer, Tim and J{\o}rgensen, Torben and Eriksson, Johan G and O{\textquoteright}Leary, Peter C and Wichmann, Eric and Hermus, Ad R and Psaty, Bruce M and Ittermann, Till and Hofman, Albert and Bosi, Emanuele and Schlessinger, David and Wallaschofski, Henri and Pirastu, Nicola and Aulchenko, Yurii S and de la Chapelle, Albert and Netea-Maier, Romana T and Gough, Stephen C L and Meyer Zu Schwabedissen, Henriette and Frayling, Timothy M and Kaufman, Jean-Marc and Linneberg, Allan and R{\"a}ikk{\"o}nen, Katri and Smit, Johannes W A and Kiemeney, Lambertus A and Rivadeneira, Fernando and Uitterlinden, Andr{\'e} G and Walsh, John P and Meisinger, Christa and den Heijer, Martin and Visser, Theo J and Spector, Timothy D and Wilson, Scott G and V{\"o}lzke, Henry and Cappola, Anne and Toniolo, Daniela and Sanna, Serena and Naitza, Silvia and Peeters, Robin P} } @article {6800, title = {Subclinical Hypothyroidism and the Risk of Stroke Events and Fatal Stroke: An Individual Participant Data Analysis.}, journal = {J Clin Endocrinol Metab}, volume = {100}, year = {2015}, month = {2015 Jun}, pages = {2181-91}, abstract = {

OBJECTIVE: The objective was to determine the risk of stroke associated with subclinical hypothyroidism.

DATA SOURCES AND STUDY SELECTION: Published prospective cohort studies were identified through a systematic search through November 2013 without restrictions in several databases. Unpublished studies were identified through the Thyroid Studies Collaboration. We collected individual participant data on thyroid function and stroke outcome. Euthyroidism was defined as TSH levels of 0.45-4.49 mIU/L, and subclinical hypothyroidism was defined as TSH levels of 4.5-19.9 mIU/L with normal T4 levels.

DATA EXTRACTION AND SYNTHESIS: We collected individual participant data on 47 573 adults (3451 subclinical hypothyroidism) from 17 cohorts and followed up from 1972-2014 (489 192 person-years). Age- and sex-adjusted pooled hazard ratios (HRs) for participants with subclinical hypothyroidism compared to euthyroidism were 1.05 (95\% confidence interval [CI], 0.91-1.21) for stroke events (combined fatal and nonfatal stroke) and 1.07 (95\% CI, 0.80-1.42) for fatal stroke. Stratified by age, the HR for stroke events was 3.32 (95\% CI, 1.25-8.80) for individuals aged 18-49 years. There was an increased risk of fatal stroke in the age groups 18-49 and 50-64 years, with a HR of 4.22 (95\% CI, 1.08-16.55) and 2.86 (95\% CI, 1.31-6.26), respectively (p trend 0.04). We found no increased risk for those 65-79 years old (HR, 1.00; 95\% CI, 0.86-1.18) or >= 80 years old (HR, 1.31; 95\% CI, 0.79-2.18). There was a pattern of increased risk of fatal stroke with higher TSH concentrations.

CONCLUSIONS: Although no overall effect of subclinical hypothyroidism on stroke could be demonstrated, an increased risk in subjects younger than 65 years and those with higher TSH concentrations was observed.

}, keywords = {Adult, Asymptomatic Diseases, Female, Humans, Hypothyroidism, Incidence, Male, Risk Factors, Stroke, Thyrotropin}, issn = {1945-7197}, doi = {10.1210/jc.2015-1438}, author = {Chaker, Layal and Baumgartner, Christine and den Elzen, Wendy P J and Ikram, M Arfan and Blum, Manuel R and Collet, Tinh-Hai and Bakker, Stephan J L and Dehghan, Abbas and Drechsler, Christiane and Luben, Robert N and Hofman, Albert and Portegies, Marileen L P and Medici, Marco and Iervasi, Giorgio and Stott, David J and Ford, Ian and Bremner, Alexandra and Wanner, Christoph and Ferrucci, Luigi and Newman, Anne B and Dullaart, Robin P and Sgarbi, Jos{\'e} A and Ceresini, Graziano and Maciel, Rui M B and Westendorp, Rudi G and Jukema, J Wouter and Imaizumi, Misa and Franklyn, Jayne A and Bauer, Douglas C and Walsh, John P and Razvi, Salman and Khaw, Kay-Tee and Cappola, Anne R and V{\"o}lzke, Henry and Franco, Oscar H and Gussekloo, Jacobijn and Rodondi, Nicolas and Peeters, Robin P} } @article {6798, title = {Thyroid function within the normal range and risk of coronary heart disease: an individual participant data analysis of 14 cohorts.}, journal = {JAMA Intern Med}, volume = {175}, year = {2015}, month = {2015 Jun}, pages = {1037-47}, abstract = {

IMPORTANCE: Some experts suggest that serum thyrotropin levels in the upper part of the current reference range should be considered abnormal, an approach that would reclassify many individuals as having mild hypothyroidism. Health hazards associated with such thyrotropin levels are poorly documented, but conflicting evidence suggests that thyrotropin levels in the upper part of the reference range may be associated with an increased risk of coronary heart disease (CHD).

OBJECTIVE: To assess the association between differences in thyroid function within the reference range and CHD risk.

DESIGN, SETTING, AND PARTICIPANTS: Individual participant data analysis of 14 cohorts with baseline examinations between July 1972 and April 2002 and with median follow-up ranging from 3.3 to 20.0 years. Participants included 55,412 individuals with serum thyrotropin levels of 0.45 to 4.49 mIU/L and no previously known thyroid or cardiovascular disease at baseline.

EXPOSURES: Thyroid function as expressed by serum thyrotropin levels at baseline.

MAIN OUTCOMES AND MEASURES: Hazard ratios (HRs) of CHD mortality and CHD events according to thyrotropin levels after adjustment for age, sex, and smoking status.

RESULTS: Among 55,412 individuals, 1813 people (3.3\%) died of CHD during 643,183 person-years of follow-up. In 10 cohorts with information on both nonfatal and fatal CHD events, 4666 of 48,875 individuals (9.5\%) experienced a first-time CHD event during 533,408 person-years of follow-up. For each 1-mIU/L higher thyrotropin level, the HR was 0.97 (95\% CI, 0.90-1.04) for CHD mortality and 1.00 (95\% CI, 0.97-1.03) for a first-time CHD event. Similarly, in analyses by categories of thyrotropin, the HRs of CHD mortality (0.94 [95\% CI, 0.74-1.20]) and CHD events (0.97 [95\% CI, 0.83-1.13]) were similar among participants with the highest (3.50-4.49 mIU/L) compared with the lowest (0.45-1.49 mIU/L) thyrotropin levels. Subgroup analyses by sex and age group yielded similar results.

CONCLUSIONS AND RELEVANCE: Thyrotropin levels within the reference range are not associated with risk of CHD events or CHD mortality. This finding suggests that differences in thyroid function within the population reference range do not influence the risk of CHD. Increased CHD risk does not appear to be a reason for lowering the upper thyrotropin reference limit.

}, keywords = {Cohort Studies, Coronary Disease, Humans, Hypothyroidism, Thyrotropin}, issn = {2168-6114}, doi = {10.1001/jamainternmed.2015.0930}, author = {Asvold, Bj{\o}rn O and Vatten, Lars J and Bj{\o}ro, Trine and Bauer, Douglas C and Bremner, Alexandra and Cappola, Anne R and Ceresini, Graziano and den Elzen, Wendy P J and Ferrucci, Luigi and Franco, Oscar H and Franklyn, Jayne A and Gussekloo, Jacobijn and Iervasi, Giorgio and Imaizumi, Misa and Kearney, Patricia M and Khaw, Kay-Tee and Maciel, Rui M B and Newman, Anne B and Peeters, Robin P and Psaty, Bruce M and Razvi, Salman and Sgarbi, Jos{\'e} A and Stott, David J and Trompet, Stella and Vanderpump, Mark P J and V{\"o}lzke, Henry and Walsh, John P and Westendorp, Rudi G J and Rodondi, Nicolas} } @article {7238, title = {Thyroid Function Within the Reference Range and the Risk of Stroke: An Individual Participant Data Analysis.}, journal = {J Clin Endocrinol Metab}, volume = {101}, year = {2016}, month = {2016 Nov}, pages = {4270-4282}, abstract = {

CONTEXT: The currently applied reference ranges for thyroid function are under debate. Despite evidence that thyroid function within the reference range is related with several cardiovascular disorders, its association with the risk of stroke has not been evaluated previously.

DESIGN AND SETTING: We identified studies through a systematic literature search and the Thyroid Studies Collaboration, a collaboration of prospective cohort studies. Studies measuring baseline TSH, free T4, and stroke outcomes were included, and we collected individual participant data from each study, including thyroid function measurements and incident all stroke (combined fatal and nonfatal) and fatal stroke. The applied reference range for TSH levels was between 0.45 and 4.49 mIU/L.

RESULTS: We collected individual participant data on 43 598 adults with TSH within the reference range from 17 cohorts, with a median follow-up of 11.6 years (interquartile range 5.1-13.9), including 449 908 person-years. Age- and sex-adjusted pooled hazard ratio for TSH was 0.78 (95\% confidence interval [CI] 0.65-0.95 across the reference range of TSH) for all stroke and 0.83 (95\% CI 0.62-1.09) for fatal stroke. For the free T4 analyses, the hazard ratio was 1.08 (95\% CI 0.99-1.15 per SD increase) for all stroke and 1.10 (95\% CI 1.04-1.19) for fatal stroke. This was independent of cardiovascular risk factors including systolic blood pressure, total cholesterol, smoking, and prevalent diabetes.

CONCLUSION: Higher levels of TSH within the reference range may decrease the risk of stroke, highlighting the need for further research focusing on the clinical consequences associated with differences within the reference range of thyroid function.

}, issn = {1945-7197}, doi = {10.1210/jc.2016-2255}, author = {Chaker, Layal and Baumgartner, Christine and den Elzen, Wendy P J and Collet, Tinh-Hai and Ikram, M Arfan and Blum, Manuel R and Dehghan, Abbas and Drechsler, Christiane and Luben, Robert N and Portegies, Marileen L P and Iervasi, Giorgio and Medici, Marco and Stott, David J and Dullaart, Robin P and Ford, Ian and Bremner, Alexandra and Newman, Anne B and Wanner, Christoph and Sgarbi, Jos{\'e} A and D{\"o}rr, Marcus and Longstreth, W T and Psaty, Bruce M and Ferrucci, Luigi and Maciel, Rui M B and Westendorp, Rudi G and Jukema, J Wouter and Ceresini, Graziano and Imaizumi, Misa and Hofman, Albert and Bakker, Stephan J L and Franklyn, Jayne A and Khaw, Kay-Tee and Bauer, Douglas C and Walsh, John P and Razvi, Salman and Gussekloo, Jacobijn and V{\"o}lzke, Henry and Franco, Oscar H and Cappola, Anne R and Rodondi, Nicolas and Peeters, Robin P} }