Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00094237 |
| Other study ID # |
1274 |
| Secondary ID |
R01HL076645 |
| Status |
Completed |
| Phase |
N/A
|
| First received |
October 15, 2004 |
| Last updated |
April 21, 2017 |
| Start date |
September 2004 |
| Est. completion date |
July 2007 |
Study information
| Verified date |
December 2015 |
| Source |
University of North Carolina, Chapel Hill |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
To examine the association of subclinical hypothyroidism and risk of myocardial infarction
and stroke in a large prospective cohort of post-menopausal women.
Description:
BACKGROUND:
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.
DESIGN NARRATIVE:
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
