1. Thyroid Function Within the Reference Range and the Risk of Stroke: An Individual Participant Data Analysis
- Author
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Jayne A. Franklyn, W. T. Longstreth, Jacobijn Gussekloo, Tinh-Hai Collet, Misa Imaizumi, Robert Luben, Christine Baumgartner, Bruce M. Psaty, John P. Walsh, Kay-Tee Khaw, Anne B. Newman, Layal Chaker, Luigi Ferrucci, J. Wouter Jukema, Rui M. B. Maciel, Christoph Wanner, Marcus Dörr, Christiane Drechsler, Giorgio Iervasi, Alexandra Bremner, Graziano Ceresini, Manuel R. Blum, Ian Ford, Salman Razvi, Nicolas Rodondi, Wendy P. J. den Elzen, Stephan J. L. Bakker, M. Arfan Ikram, Rudi G. J. Westendorp, David J. Stott, Robin P. Peeters, Henry Völzke, José Augusto Sgarbi, Douglas C. Bauer, Anne R. Cappola, Oscar H. Franco, Marileen L.P. Portegies, Albert Hofman, Abbas Dehghan, Robin P. F. Dullaart, Marco Medici, Internal Medicine, Neurology, Radiology & Nuclear Medicine, Epidemiology, Lifestyle Medicine (LM), Groningen Institute for Organ Transplantation (GIOT), Groningen Kidney Center (GKC), and Thyroid Studies Collaboration
- Subjects
medicine.medical_specialty ,endocrine system ,endocrine system diseases ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,BLOOD-PRESSURE ,030209 endocrinology & metabolism ,Reference range ,Context (language use) ,ISCHEMIC-HEART-DISEASE ,ALL-CAUSE ,030204 cardiovascular system & hematology ,Biochemistry ,03 medical and health sciences ,SUBCLINICAL HYPOTHYROIDISM ,0302 clinical medicine ,Endocrinology ,Interquartile range ,Internal medicine ,medicine ,OLDER-ADULTS ,Prospective cohort study ,Stroke ,business.industry ,CARDIOVASCULAR RISK ,Biochemistry (medical) ,Thyroid ,Original Articles ,medicine.disease ,DYSFUNCTION ,3. Good health ,SERVICES TASK-FORCE ,medicine.anatomical_structure ,SERUM THYROTROPIN ,MYOCARDIAL-INFARCTION ,Meta-analysis ,Thyroid function ,business ,hormones, hormone substitutes, and hormone antagonists - 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 T-4, 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.
- Published
- 2016