Jonathan Golledge1, Graeme J Hankey2, Osvaldo P Almeida3, Leon Flicker4, Paul E Norman5, Bu B Yeap6. 1. Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Australia; Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Australia. Electronic address: jonathan.golledge@jcu.edu.au. 2. School of Medicine, University of Western Australia, Perth, Australia; Department of Neurology, Sir Charles Gairdner, Perth, Australia. 3. WA Centre for Health & Ageing, Centre for Medical Research, Perth, Australia; Medical School, University of Western Australia, Perth, Australia; Department of Psychiatry, Royal Perth Hospital, Perth, Australia. 4. School of Medicine, University of Western Australia, Perth, Australia; WA Centre for Health & Ageing, Centre for Medical Research, Perth, Australia; Department of Geriatric Medicine, Royal Perth Hospital, Perth, Australia. 5. School of Surgery, University of Western Australia and Department of Surgery, Fiona Stanley Hospital, Perth, Australia. 6. School of Medicine, University of Western Australia, Perth, Australia; Department of Endocrinology, Fiona Stanley Hospital, Perth, Australia.
Abstract
BACKGROUND: The aim of this study was to assess the association of plasma free thyroxine (FT4) and serum thyroid stimulating hormone (TSH) concentrations with the past diagnosis of cardiovascular disease and incidence of new cardiovascular events in older men with no known thyroid disease. METHODS: This study involved a cohort of community-recruited older men without known thyroid disease. Plasma FT4 and serum TSH were measured by immunoassay. Past cardiovascular disease diagnosis was defined through questionnaire data. The incidence of major cardiovascular events were assessed using the Western Australian Data Linkage System. The associations of plasma FT4 and serum TSH with the past diagnosis of cardiovascular disease and the incidence of new major cardiovascular events (cardiovascular death, myocardial infarction or stroke) were examined using logistic regression and Cox proportional hazard analyses. RESULTS:3712 men were followed for a mean of 9.5years. Men with plasma FT4 in the upper quartile, compared to other men, were more likely to have been previously diagnosed with cardiovascular disease but this association did not persist after adjustment for other risk factors. Men with plasma FT4 in the upper quartile, compared to other men, had an increased incidence of major cardiovascular events (adjusted hazard ratio, HR, 1.15, 95% CI 1.00-1.31) and myocardial infarction alone (adjusted HR 1.29, 95% CI 1.06-1.54). CONCLUSION: This study suggests that older men with higher levels of plasma FT4 not meeting current criteria for the diagnosis of hyperthyroidism are at increased risk of major cardiovascular events. Crown
RCT Entities:
BACKGROUND: The aim of this study was to assess the association of plasma free thyroxine (FT4) and serum thyroid stimulating hormone (TSH) concentrations with the past diagnosis of cardiovascular disease and incidence of new cardiovascular events in older men with no known thyroid disease. METHODS: This study involved a cohort of community-recruited older men without known thyroid disease. Plasma FT4 and serum TSH were measured by immunoassay. Past cardiovascular disease diagnosis was defined through questionnaire data. The incidence of major cardiovascular events were assessed using the Western Australian Data Linkage System. The associations of plasma FT4 and serum TSH with the past diagnosis of cardiovascular disease and the incidence of new major cardiovascular events (cardiovascular death, myocardial infarction or stroke) were examined using logistic regression and Cox proportional hazard analyses. RESULTS: 3712 men were followed for a mean of 9.5years. Men with plasma FT4 in the upper quartile, compared to other men, were more likely to have been previously diagnosed with cardiovascular disease but this association did not persist after adjustment for other risk factors. Men with plasma FT4 in the upper quartile, compared to other men, had an increased incidence of major cardiovascular events (adjusted hazard ratio, HR, 1.15, 95% CI 1.00-1.31) and myocardial infarction alone (adjusted HR 1.29, 95% CI 1.06-1.54). CONCLUSION: This study suggests that older men with higher levels of plasma FT4 not meeting current criteria for the diagnosis of hyperthyroidism are at increased risk of major cardiovascular events. Crown