@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} }