@article {1067, title = {High frequency of and factors associated with thyroid hormone over-replacement and under-replacement in men and women aged 65 and over.}, journal = {J Clin Endocrinol Metab}, volume = {94}, year = {2009}, month = {2009 Apr}, pages = {1342-5}, abstract = {

CONTEXT: Thyroid hormone use is common in older populations, but the frequency of over- or under-replacement is debated.

OBJECTIVE: We sought to describe the frequency of and factors associated with thyroid hormone over- or under-replacement in a population of older men and women.

DESIGN: Participants were 3678 U.S. community dwelling individuals aged 65 yr or older enrolled in the Cardiovascular Health Study who had thyroid function tests in 1989-1990. Thyroid hormone users (n = 339) were identified and classified into low TSH (<0.45 mU/liter), euthyroid (0.45-4.5 mU/liter), and high TSH (>4.5 mU/liter).

RESULTS: Of the 339 thyroid hormone users, 41\% had a low TSH, 16\% had a high TSH, and 43\% were in the euthyroid range. In multivariable analyses, lower weight (P < 0.001) was independently associated with low TSH status. For every 10 kg lower weight, the likelihood of having low TSH increased by 65\% [odd ratio (OR) 1.65; 95\% confidence interval (CI) 1.31-2.07]. Those with renal insufficiency were less likely to have low TSH levels (P = 0.02). The presence of diabetes was independently associated with having low (OR 3.35; 95\% CI 1.46-7.65) and high TSH levels (OR 2.66; 95\% CI 1.14-6.21).

CONCLUSIONS: There is a very high prevalence of thyroid function testing abnormalities in older people taking thyroid hormone preparations, particularly in those of low weight or with diabetes. Because of potential adverse cardiovascular and skeletal effects from over-replacement, older people represent a key population for increased TSH monitoring on therapy.

}, keywords = {Aged, Body Mass Index, Body Weight, Diabetes Mellitus, Dose-Response Relationship, Drug, Drug Therapy, Combination, Female, Hormone Replacement Therapy, Humans, Male, Multivariate Analysis, Renal Insufficiency, Risk Factors, Thyroid Diseases, Thyroid Hormones, Thyrotropin, Thyroxine, Triiodothyronine}, issn = {1945-7197}, doi = {10.1210/jc.2008-1696}, author = {Somwaru, Lily L and Arnold, Alice M and Joshi, Neha and Fried, Linda P and Cappola, Anne R} } @article {1293, title = {Predictors of thyroid hormone initiation in older adults: results from the cardiovascular health study.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {66}, year = {2011}, month = {2011 Jul}, pages = {809-14}, abstract = {

BACKGROUND: Despite widespread use, there are no data on initiation of thyroid hormone use in older people. We report the prevalence of thyroid hormone use and predictors of thyroid hormone initiation in a population of older men and women.

METHODS: Thyroid hormone medication data were collected annually from 1989 to 2006 in community-dwelling individuals aged 65 years and older enrolled in the Cardiovascular Health Study (N = 5,888). Associations of age, sex, race, body mass index, education, and coronary heart disease with initiation were evaluated using discrete-time survival analysis.

RESULTS: In 1989-1990, 8.9\% (95\% confidence interval 8.1\%-9.7\%) of participants were taking a thyroid hormone preparation, increasing to 20.0\% (95\% confidence interval 8.2\%-21.8\%) over 16 years. The average initiation rate was 1\% per year. The initiation rate was nonlinear with age, and those aged 85 years and older initiated thyroid hormone more than twice as frequently as those aged 65-69 years (hazard ratio = 2.34; 95\% confidence interval 1.43-3.85). White women were more likely to initiate thyroid hormone than any other race and sex group. Higher body mass index was independently associated with higher risk for initiation (p = .002) as was greater education (p = .02) and prevalent coronary heart disease (p = .03).

CONCLUSIONS: Thyroid hormone use is common in older people. The indications and benefits of thyroid hormone use in older individuals with the highest rate of thyroid hormone initiation-the oldest old, overweight and obese individuals, and those with coronary heart disease-should be investigated.

}, keywords = {Aged, Aged, 80 and over, Body Mass Index, Cardiovascular Diseases, Dose-Response Relationship, Drug, Drug Administration Schedule, Female, Follow-Up Studies, Humans, Hypothyroidism, Incidence, Male, Prevalence, Prognosis, Retrospective Studies, Risk Factors, Sex Factors, Thyroid Hormones, Thyroxine, Time Factors, United States}, issn = {1758-535X}, doi = {10.1093/gerona/glr063}, author = {Somwaru, Lily L and Arnold, Alice M and Cappola, Anne R} } @article {1404, title = {Longitudinal changes in thyroid function in the oldest old and survival: the cardiovascular health study all-stars study.}, journal = {J Clin Endocrinol Metab}, volume = {97}, year = {2012}, month = {2012 Nov}, pages = {3944-50}, abstract = {

CONTEXT: Data on thyroid function in the oldest old are sparse, and existing studies show conflicting evidence on the relationship between thyroid function and mortality in this age group.

OBJECTIVE: We describe longitudinal changes in thyroid function in a cohort of elderly individuals and determine the relationship between thyroid function and mortality.

DESIGN, SETTING, AND PARTICIPANTS: Eight hundred forty-three participants in the Cardiovascular Health Study All Stars Study who were not taking thyroid medications and had thyroid function testing in 2005-2006 (mean age 85 yr).

MAIN OUTCOME MEASURE: Thyroid-stimulating hormone (TSH), free T(4) (FT4), total T(3), and thyroid peroxidase antibody status were measured in 1992-1993 and 2005-2006. Deaths were ascertained through February 2011.

RESULTS: There was a statistically significant 13\% increase in TSH, 1.7\% increase in FT4, and 13\% decrease in total T(3) over the 13-yr period. Two hundred eighty-seven deaths occurred over a median follow-up of 5.1 yr. There was no association between subclinical hypothyroidism[hazard ratio (HR) 0.97, 95\% confidence interval (CI) 0.66-1.43], TSH level (HR per milliunits per liter 0.94, 95\% CI 0.88-1.01), or persistent thyroid peroxidase antibody positivity (HR 1.09, 95\% CI 0.62-1.92), and death. However, FT4 was positively associated with death (HR per nanograms per deciliter 2.57, 95\% CI 1.32-5.02).

CONCLUSIONS: TSH increased over time in these older individuals. This elevation was not associated with increased or decreased mortality, although higher FT4 levels were associated with death. These findings raise concern for treatment of mild elevations of TSH in advanced age. Further studies are needed to determine the potential benefit of treating age-related changes in thyroid function.

}, keywords = {Aged, 80 and over, Female, Humans, Longitudinal Studies, Male, Thyroid Diseases, Thyroid Function Tests, Thyroid Gland, Thyrotropin, Thyroxine, Triiodothyronine}, issn = {1945-7197}, doi = {10.1210/jc.2012-2481}, author = {Waring, Avantika C and Arnold, Alice M and Newman, Anne B and B{\r u}zkov{\'a}, Petra and Hirsch, Calvin and Cappola, Anne R} } @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 {5877, title = {A meta-analysis of thyroid-related traits reveals novel loci and gender-specific differences in the regulation of thyroid function.}, journal = {PLoS Genet}, volume = {9}, year = {2013}, month = {2013}, pages = {e1003266}, abstract = {

Thyroid hormone is essential for normal metabolism and development, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10\% of individuals over their life span. In addition, even mild alterations in thyroid function are associated with weight changes, atrial fibrillation, osteoporosis, and psychiatric disorders. To identify novel variants underlying thyroid function, we performed a large meta-analysis of genome-wide association studies for serum levels of the highly heritable thyroid function markers TSH and FT4, in up to 26,420 and 17,520 euthyroid subjects, respectively. Here we report 26 independent associations, including several novel loci for TSH (PDE10A, VEGFA, IGFBP5, NFIA, SOX9, PRDM11, FGF7, INSR, ABO, MIR1179, NRG1, MBIP, ITPK1, SASH1, GLIS3) and FT4 (LHX3, FOXE1, AADAT, NETO1/FBXO15, LPCAT2/CAPNS2). Notably, only limited overlap was detected between TSH and FT4 associated signals, in spite of the feedback regulation of their circulating levels by the hypothalamic-pituitary-thyroid axis. Five of the reported loci (PDE8B, PDE10A, MAF/LOC440389, NETO1/FBXO15, and LPCAT2/CAPNS2) show strong gender-specific differences, which offer clues for the known sexual dimorphism in thyroid function and related pathologies. Importantly, the TSH-associated loci contribute not only to variation within the normal range, but also to TSH values outside the reference range, suggesting that they may be involved in thyroid dysfunction. Overall, our findings explain, respectively, 5.64\% and 2.30\% of total TSH and FT4 trait variance, and they improve the current knowledge of the regulation of hypothalamic-pituitary-thyroid axis function and the consequences of genetic variation for hypo- or hyperthyroidism.

}, keywords = {Female, Genome-Wide Association Study, Humans, Hyperthyroidism, Hypothyroidism, Male, Phenotype, Polymorphism, Genetic, Polymorphism, Single Nucleotide, Sex Characteristics, Signal Transduction, Thyroid Gland, Thyrotropin, Thyroxine}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003266}, author = {Porcu, Eleonora and Medici, Marco and Pistis, Giorgio and Volpato, Claudia B and Wilson, Scott G and Cappola, Anne R and Bos, Steffan D and Deelen, Joris and den Heijer, Martin and Freathy, Rachel M and Lahti, Jari and Liu, Chunyu and Lopez, Lorna M and Nolte, Ilja M and O{\textquoteright}Connell, Jeffrey R and Tanaka, Toshiko and Trompet, Stella and Arnold, Alice and Bandinelli, Stefania and Beekman, Marian and B{\"o}hringer, Stefan and Brown, Suzanne J and Buckley, Brendan M and Camaschella, Clara and de Craen, Anton J M and Davies, Gail and de Visser, Marieke C H and Ford, Ian and Forsen, Tom and Frayling, Timothy M and Fugazzola, Laura and G{\"o}gele, Martin and Hattersley, Andrew T and Hermus, Ad R and Hofman, Albert and Houwing-Duistermaat, Jeanine J and Jensen, Richard A and Kajantie, Eero and Kloppenburg, Margreet and Lim, Ee M and Masciullo, Corrado and Mariotti, Stefano and Minelli, Cosetta and Mitchell, Braxton D and Nagaraja, Ramaiah and Netea-Maier, Romana T and Palotie, Aarno and Persani, Luca and Piras, Maria G and Psaty, Bruce M and R{\"a}ikk{\"o}nen, Katri and Richards, J Brent and Rivadeneira, Fernando and Sala, Cinzia and Sabra, Mona M and Sattar, Naveed and Shields, Beverley M and Soranzo, Nicole and Starr, John M and Stott, David J and Sweep, Fred C G J and Usala, Gianluca and van der Klauw, Melanie M and van Heemst, Diana and van Mullem, Alies and Vermeulen, Sita H and Visser, W Edward and Walsh, John P and Westendorp, Rudi G J and Widen, Elisabeth and Zhai, Guangju and Cucca, Francesco and Deary, Ian J and Eriksson, Johan G and Ferrucci, Luigi and Fox, Caroline S and Jukema, J Wouter and Kiemeney, Lambertus A and Pramstaller, Peter P and Schlessinger, David and Shuldiner, Alan R and Slagboom, Eline P and Uitterlinden, Andr{\'e} G and Vaidya, Bijay and Visser, Theo J and Wolffenbuttel, Bruce H R and Meulenbelt, Ingrid and Rotter, Jerome I and Spector, Tim D and Hicks, Andrew A and Toniolo, Daniela and Sanna, Serena and Peeters, Robin P and Naitza, Silvia} } @article {7550, title = {Thyroid Function Within the Normal Range, Subclinical Hypothyroidism, and the Risk of Atrial Fibrillation.}, journal = {Circulation}, volume = {136}, year = {2017}, month = {2017 Nov 28}, pages = {2100-2116}, abstract = {

BACKGROUND: Atrial fibrillation (AF) is a highly prevalent disorder leading to heart failure, stroke, and death. Enhanced understanding of modifiable risk factors may yield opportunities for prevention. The risk of AF is increased in subclinical hyperthyroidism, but it is uncertain whether variations in thyroid function within the normal range or subclinical hypothyroidism are also associated with AF.

METHODS: We conducted a systematic review and obtained individual participant data from prospective cohort studies that measured thyroid function at baseline and assessed incident AF. Studies were identified from MEDLINE and EMBASE databases from inception to July 27, 2016. The euthyroid state was defined as thyroid-stimulating hormone (TSH) 0.45 to 4.49 mIU/L, and subclinical hypothyroidism as TSH 4.5 to 19.9 mIU/L with free thyroxine (fT4) levels within reference range. The association of TSH levels in the euthyroid and subclinical hypothyroid range with incident AF was examined by using Cox proportional hazards models. In euthyroid participants, we additionally examined the association between fT4 levels and incident AF.

RESULTS: Of 30 085 participants from 11 cohorts (278 955 person-years of follow-up), 1958 (6.5\%) had subclinical hypothyroidism and 2574 individuals (8.6\%) developed AF during follow-up. TSH at baseline was not significantly associated with incident AF in euthyroid participants or those with subclinical hypothyroidism. Higher fT4 levels at baseline in euthyroid individuals were associated with increased AF risk in age- and sex-adjusted analyses (hazard ratio, 1.45; 95\% confidence interval, 1.26-1.66, for the highest quartile versus the lowest quartile of fT4; P for trend <=0.001 across quartiles). Estimates did not substantially differ after further adjustment for preexisting cardiovascular disease.

CONCLUSIONS: In euthyroid individuals, higher circulating fT4 levels, but not TSH levels, are associated with increased risk of incident AF.

}, keywords = {Adult, Aged, Aged, 80 and over, Asymptomatic Diseases, Atrial Fibrillation, Biomarkers, Chi-Square Distribution, Female, Humans, Hypothyroidism, Incidence, Male, Middle Aged, Predictive Value of Tests, Prognosis, Proportional Hazards Models, Risk Assessment, Risk Factors, Thyroid Function Tests, Thyroid Gland, Thyrotropin, Thyroxine, Time Factors, Young Adult}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.117.028753}, author = {Baumgartner, Christine and da Costa, Bruno R and Collet, Tinh-Hai and Feller, Martin and Floriani, Carmen and Bauer, Douglas C and Cappola, Anne R and Heckbert, Susan R and Ceresini, Graziano and Gussekloo, Jacobijn and den Elzen, Wendy P J and Peeters, Robin P and Luben, Robert and V{\"o}lzke, Henry and D{\"o}rr, Marcus and Walsh, John P and Bremner, Alexandra and Iacoviello, Massimo and Macfarlane, Peter and Heeringa, Jan and Stott, David J and Westendorp, Rudi G J and Khaw, Kay-Tee and Magnani, Jared W and Aujesky, Drahomir and Rodondi, Nicolas} }