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Subclinical Thyroid Dysfunction and Risk of Myocardial Infarction and Stroke

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ClinicalTrials.gov Identifier: NCT00094237
Recruitment Status : Completed
First Posted : October 15, 2004
Last Update Posted : April 25, 2017
Information provided by (Responsible Party):

Study Description
Brief Summary:
To examine the association of subclinical hypothyroidism and risk of myocardial infarction and stroke in a large prospective cohort of post-menopausal women.

Condition or disease
Cardiovascular Diseases Heart Diseases Hypothyroidism Myocardial Infarction Cerebrovascular Accident

Detailed Description:


Cardiovascular disease, including myocardial infarction (MI) and stroke, is the leading cause of death for women in the United States. Subclinical hypothyroidism (SCH), in which thyroid hormone levels are in the normal range but thyroid stimulating hormone (TSH) is elevated, has been linked to abnormal lipid profiles, atherosclerosis, and MI. The literature is scant however, and the evidence constrained by small studies, many of cross-sectional design. Both the US Preventive Services Task Force and the Institute of Medicine recently concluded that current data are insufficient to inform clinical decision-making about the need for screening or treatment for SCH.


This is a case-cohort study within the 93,676-member Observational Study of the Women's Health Initiative, including 800 women who have experienced an MI, 750 with thrombotic/embolic stroke, and a randomly selected subcohort of 3,200 women density-matched for age, race/ethnicity, and clinical center. Participants have extensive baseline demographic, health, behavioral, and physical exam data and stored serum available. The investigators will measure TSH and thyroid hormone levels in order to identify SCH at entry. Follow-up includes annual health status updates and a physical exam in the third year; >=5 years have passed since enrollment for all women. Thus, using new laboratory studies and existing Women's Health Initiative (WHI) data, they will be able to answer these primary research questions: Among women without a history of thyroid disease, MI, or stroke: 1) Is subclinical hypothyroidism at baseline independently associated with risk of MI? 2) Is subclinical hypothyroidism at baseline independently associated with risk of ischemic stroke? 3) What form of association best describes the relationship between TSH, as a continuous measure, and risk of MI and stroke? 4) What are the population correlates (i.e., race/ethnicity, body mass index (BMI), hormone therapy, comorbidity) of SCH? This information - currently unavailable for middle-aged and older women - is germane to public health and health care policy to define the burden of illness associated with SCH, and to quantify the benefits and costs of eventual population screening and treatment

Study Design

Study Type : Observational
Actual Enrollment : 3200 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Subclinical Thyroid Dysfunction and Risk of Myocardial Infarction and Stroke
Study Start Date : September 2004
Primary Completion Date : July 2007
Study Completion Date : July 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Attack
U.S. FDA Resources

Groups and Cohorts

Outcome Measures

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years to 79 Years   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Postmenopausal women aged 50-79 years, who enrolled in the Women's Health Initiative (WHI) Observational Study (n=93,676). Participants include African American, Asian, Hispanic/Latino and European-American individuals recruited from the communities surrounding the WHI study centers..
No eligibility criteria
Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00094237

Sponsors and Collaborators
University of North Carolina, Chapel Hill
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Katherine Hartmann University of North Carolina, Chapel Hill
More Information

Responsible Party: University of North Carolina, Chapel Hill
ClinicalTrials.gov Identifier: NCT00094237     History of Changes
Other Study ID Numbers: 1274
R01HL076645 ( U.S. NIH Grant/Contract )
First Posted: October 15, 2004    Key Record Dates
Last Update Posted: April 25, 2017
Last Verified: December 2015

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Myocardial Infarction
Pathologic Processes
Myocardial Ischemia
Vascular Diseases
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Thyroid Diseases
Endocrine System Diseases