@article {1053, title = {Subclinical thyroid dysfunction, cardiac function, and the risk of heart failure. The Cardiovascular Health study.}, journal = {J Am Coll Cardiol}, volume = {52}, year = {2008}, month = {2008 Sep 30}, pages = {1152-9}, abstract = {

OBJECTIVES: The goal of this study was to determine whether subclinical thyroid dysfunction was associated with incident heart failure (HF) and echocardiogram abnormalities.

BACKGROUND: Subclinical hypothyroidism and hyperthyroidism have been associated with cardiac dysfunction. However, long-term data on the risk of HF are limited.

METHODS: We studied 3,044 adults>or=65 years of age who initially were free of HF in the Cardiovascular Health Study. We compared adjudicated HF events over a mean 12-year follow-up and changes in cardiac function over the course of 5 years among euthyroid participants, those with subclinical hypothyroidism (subdivided by thyroid-stimulating hormone [TSH] levels: 4.5 to 9.9, >or=10.0 mU/l), and those with subclinical hyperthyroidism.

RESULTS: Over the course of 12 years, 736 participants developed HF events. Participants with TSH>or=10.0 mU/l had a greater incidence of HF compared with euthyroid participants (41.7 vs. 22.9 per 1,000 person years, p=0.01; adjusted hazard ratio: 1.88; 95\% confidence interval: 1.05 to 3.34). Baseline peak E velocity, which is an echocardiographic measurement of diastolic function associated with incident HF in the CHS cohort, was greater in those patients with TSH>or=10.0 mU/l compared with euthyroid participants (0.80 m/s vs. 0.72 m/s, p=0.002). Over the course of 5 years, left ventricular mass increased among those with TSH>or=10.0 mU/l, but other echocardiographic measurements were unchanged. Those patients with TSH 4.5 to 9.9 mU/l or with subclinical hyperthyroidism had no increase in risk of HF.

CONCLUSIONS: Compared with euthyroid older adults, those adults with TSH>or=10.0 mU/l have a moderately increased risk of HF and alterations in cardiac function but not older adults with TSH<10.0 mU/l. Clinical trials should assess whether the risk of HF might be ameliorated by thyroxine replacement in individuals with TSH>or=10.0 mU/l.

}, keywords = {Aged, Aged, 80 and over, Cohort Studies, Echocardiography, Female, Heart, Heart Failure, Heart Function Tests, Humans, Hyperthyroidism, Hypertrophy, Left Ventricular, Hypothyroidism, Male, Risk Factors, Time Factors}, issn = {1558-3597}, doi = {10.1016/j.jacc.2008.07.009}, author = {Rodondi, Nicolas and Bauer, Douglas C and Cappola, Anne R and Cornuz, Jacques and Robbins, John and Fried, Linda P and Ladenson, Paul W and Vittinghoff, Eric and Gottdiener, John S and Newman, Anne B} } @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 {6087, title = {Subclinical thyroid dysfunction and the risk of heart failure events: an individual participant data analysis from 6 prospective cohorts.}, journal = {Circulation}, volume = {126}, year = {2012}, month = {2012 Aug 28}, pages = {1040-9}, abstract = {

BACKGROUND: American College of Cardiology/American Heart Association guidelines for the diagnosis and management of heart failure recommend investigating exacerbating conditions such as thyroid dysfunction, but without specifying the impact of different thyroid-stimulation hormone (TSH) levels. Limited prospective data exist on the association between subclinical thyroid dysfunction and heart failure events.

METHODS AND RESULTS: We performed a pooled analysis of individual participant data using all available prospective cohorts with thyroid function tests and subsequent follow-up of heart failure events. Individual data on 25 390 participants with 216 248 person-years of follow-up were supplied from 6 prospective cohorts in the United States and Europe. Euthyroidism was defined as TSH of 0.45 to 4.49 mIU/L, subclinical hypothyroidism as TSH of 4.5 to 19.9 mIU/L, and subclinical hyperthyroidism as TSH <0.45 mIU/L, the last two with normal free thyroxine levels. Among 25 390 participants, 2068 (8.1\%) had subclinical hypothyroidism and 648 (2.6\%) had subclinical hyperthyroidism. In age- and sex-adjusted analyses, risks of heart failure events were increased with both higher and lower TSH levels (P for quadratic pattern <0.01); the hazard ratio was 1.01 (95\% confidence interval, 0.81-1.26) for TSH of 4.5 to 6.9 mIU/L, 1.65 (95\% confidence interval, 0.84-3.23) for TSH of 7.0 to 9.9 mIU/L, 1.86 (95\% confidence interval, 1.27-2.72) for TSH of 10.0 to 19.9 mIU/L (P for trend <0.01) and 1.31 (95\% confidence interval, 0.88-1.95) for TSH of 0.10 to 0.44 mIU/L and 1.94 (95\% confidence interval, 1.01-3.72) for TSH <0.10 mIU/L (P for trend=0.047). Risks remained similar after adjustment for cardiovascular risk factors.

CONCLUSION: Risks of heart failure events were increased with both higher and lower TSH levels, particularly for TSH >=10 and <0.10 mIU/L.

}, keywords = {Adult, Aged, Aged, 80 and over, Comorbidity, Female, Follow-Up Studies, Heart Failure, Humans, Hypothyroidism, Male, Middle Aged, Prospective Studies, Risk, Risk Factors, Sensitivity and Specificity, Thyrotropin, Thyroxine}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.112.096024}, author = {Gencer, Bari{\c s} and Collet, Tinh-Hai and Virgini, Vanessa and Bauer, Douglas C and Gussekloo, Jacobijn and Cappola, Anne R and Nanchen, David and den Elzen, Wendy P J and Balmer, Philippe and Luben, Robert N and Iacoviello, Massimo and Triggiani, Vincenzo and Cornuz, Jacques and Newman, Anne B and Khaw, Kay-Tee and Jukema, J Wouter and Westendorp, Rudi G J and Vittinghoff, Eric and Aujesky, Drahomir and Rodondi, Nicolas} } @article {6553, title = {Thyroid antibody status, subclinical hypothyroidism, and the risk of coronary heart disease: an individual participant data analysis.}, journal = {J Clin Endocrinol Metab}, volume = {99}, year = {2014}, month = {2014 Sep}, pages = {3353-62}, abstract = {

CONTEXT: Subclinical hypothyroidism has been associated with increased risk of coronary heart disease (CHD), particularly with thyrotropin levels of 10.0 mIU/L or greater. The measurement of thyroid antibodies helps predict the progression to overt hypothyroidism, but it is unclear whether thyroid autoimmunity independently affects CHD risk.

OBJECTIVE: The objective of the study was to compare the CHD risk of subclinical hypothyroidism with and without thyroid peroxidase antibodies (TPOAbs).

DATA SOURCES AND STUDY SELECTION: A MEDLINE and EMBASE search from 1950 to 2011 was conducted for prospective cohorts, reporting baseline thyroid function, antibodies, and CHD outcomes.

DATA EXTRACTION: Individual data of 38 274 participants from six cohorts for CHD mortality followed up for 460 333 person-years and 33 394 participants from four cohorts for CHD events.

DATA SYNTHESIS: Among 38 274 adults (median age 55 y, 63\% women), 1691 (4.4\%) had subclinical hypothyroidism, of whom 775 (45.8\%) had positive TPOAbs. During follow-up, 1436 participants died of CHD and 3285 had CHD events. Compared with euthyroid individuals, age- and gender-adjusted risks of CHD mortality in subclinical hypothyroidism were similar among individuals with and without TPOAbs [hazard ratio (HR) 1.15, 95\% confidence interval (CI) 0.87-1.53 vs HR 1.26, CI 1.01-1.58, P for interaction = .62], as were risks of CHD events (HR 1.16, CI 0.87-1.56 vs HR 1.26, CI 1.02-1.56, P for interaction = .65). Risks of CHD mortality and events increased with higher thyrotropin, but within each stratum, risks did not differ by TPOAb status.

CONCLUSIONS: CHD risk associated with subclinical hypothyroidism did not differ by TPOAb status, suggesting that biomarkers of thyroid autoimmunity do not add independent prognostic information for CHD outcomes.

}, keywords = {Adult, Aged, Aged, 80 and over, Autoantibodies, Coronary Disease, Female, Humans, Hypothyroidism, Incidence, Male, Middle Aged, Prevalence, Prognosis, Risk Factors, Seroepidemiologic Studies, Severity of Illness Index, Young Adult}, issn = {1945-7197}, doi = {10.1210/jc.2014-1250}, author = {Collet, Tinh-Hai and Bauer, Douglas C and Cappola, Anne R and Asvold, Bj{\o}rn O and Weiler, Stefan and Vittinghoff, Eric and Gussekloo, Jacobijn and Bremner, Alexandra and den Elzen, Wendy P J and Maciel, Rui M B and Vanderpump, Mark P J and Cornuz, Jacques and D{\"o}rr, Marcus and Wallaschofski, Henri and Newman, Anne B and Sgarbi, Jos{\'e} A and Razvi, Salman and V{\"o}lzke, Henry and Walsh, John P and Aujesky, Drahomir and Rodondi, Nicolas} }