title: Thyroid disease as a risk factor for cerebrovascular disease.
abstract: BACKGROUND
  Thyroid disease is the medical condition impairing function of the thyroid. Among this disorder category, hyperthyroidism is that the thyroid gland produces excessive amounts of thyroid hormones whereas hypothyroidism is that the thyroid gland does not produce enough thyroid hormone. Various studies have supported the comorbid association between thyroid disease and cardiovascular disorder. However, there is insufficient evidence to prove the relationship between cerebrovascular disease (CVD) and thyroid disease.
  
  
  METHODS
  In this study, we tried to verify that thyroid disease increases the risk of CVD development employing a population-based database, National Health Insurance Research Database of Taiwan. A total of 16,808 hyperthyroidism cases and 5793 hypothyroidism patients with corresponding control subjects were studied, respectively. Hazard ratio (HR) by the Cox regression was used to quantify risk of CVD in different groups of subjects, that is, case patients versus matched controls. Further stratification studies for risk factors of CVD were performed to evaluate the comorbid association between CVD and hyperthyroidism/hypothyroidism.
  
  
  RESULTS
  Evaluation results have shown that hyperthyroidism increased 38% of the hazard of developing follow-up CVD (adjusted HR, 1.38) whereas hypothyroidism increased even higher the risk (adjusted HR, 1.89). Further stratification studies for risk factors of CVD suggested that the comorbid association between hypothyroidism and CVD was comparable to those influences from cardiac risk factors, such as diabetes mellitus, hyperlipidemia, hypertension, or renal failure and so forth.
  
  
  CONCLUSIONS
  Thyroid disease may predispose to onset of CVD. Advanced analysis is required to investigate the pathologic mechanism underlying the association between CVD and thyroid disease.
authors: Department of Computer Science and Information Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung, Taiwan, ROC. Electronic address: menghanyang@cc.kuas.edu.tw.
authors: Meng-Han
authors: MH
authors: Yang
authors: Department of Neurology, Taipei Tzu Chi General Hospital, New Taipei, Taiwan, ROC. Electronic address: fuyi127@yahoo.com.tw.
authors: Fu-Yi
authors: FY
authors: Yang
authors: Department of Dermatology, Taipei-Veterans General Hospital, Taipei City, Taiwan, ROC; Faculty of Medicine, Department of Dermatology, National Yang-Ming University, Taipei City, Taiwan, ROC.
authors: Ding-Dar
authors: DD
authors: Lee
mesh_terms: D000328:Adult; D002561:Cerebrovascular Disorders / Q000453:epidemiology*; D015331:Cohort Studies; D018672:Community Health Planning; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013959:Thyroid Diseases / Q000145:classification / Q000453:epidemiology*; D055815:Young Adult
keywords: Hyperthyroidism; NHIRD; cerebrovascular disease; hazard ratio; hypothyroidism