Abstract 13100: Thyroid Dysfunction, Cardiovascular Risk Factors, and Incident Cardiovascular Events: The Atherosclerosis Risk in Communities (ARIC) Study
Introduction: Data remain inconclusive on the relation of thyroid dysfunction to atherosclerotic cardiovascular disease risk, particularly with respect to stroke. In addition, prior studies have lacked measurement of T3, the final active form of thyroid hormone.
Methods: We examined the cross-sectional and prospective associations of thyroid dysfunction with cardiovascular risk factors and events in the community-based ARIC Study. Participants had thyroid measures obtained in an ancillary study at visit 2 (1990-92) and were free of pre-existing cardiovascular disease. We evaluated thyroid function using clinical categories and also log-transformed T3. Cross-sectional outcomes were hypertension, diabetes, and dyslipidemia. Prospective outcomes were adjudicated fatal and non-fatal myocardial infarction and stroke, which are the outcomes of the 2013 ACC/AHA guidelines.
Results: Among 11,359 participants (mean age 57±6 years, 58% women), 2.2% had overt hypothyroidism, 4.8% subclinical hypothyroidism, 3.3% subclinical hyperthyroidism, and 1.8% overt hyperthyroidism. Compared with euthyroidism, all thyroid dysfunction groups had similar age, sex, and race-center adjusted prevalences of hypertension and diabetes. Regarding dyslipidemia, mean adjusted differences in LDL cholesterol were 15.1 (95% CI 10.5, 19.7) and 3.2 (0.0, 6.4) mg/dL in those with overt and subclinical hypothyroidism relative to euthyroidism; an opposite pattern was seen in overt and subclinical hyperthyroidism [-10.8 (-15.9, -5.7) and -3.9 (-7.7, -0.1) mg/dL, respectively]. During a median follow-up of 20 years, 966 myocardial infarctions and 721 strokes occurred, with no unadjusted or adjusted associations observed with baseline thyroid function groups or by concentration of T3 (Table).
Conclusion: Thyroid dysfunction is associated with a modest alteration in the lipid profile and no long-term differences in incidence of myocardial infarction or stroke.
Author Disclosures: N. Daya: None. P.L. Lutsey: None. K. Matsushita: Honoraria; Modest; Mitsubishi Tanabe, MSD, Sumitomo Dainippon Pharma. Consultant/Advisory Board; Modest; Kyowa Hakko Kirin, Apex. Research Grant; Significant; Fukuda Denshi, Kyowa Hakko Kirin. A. Fretz: None. J.W. McEvoy: None. R.S. Blumenthal: None. J. Coresh: None. M.W. Steffes: None. P. Greenland: None. A. Kottgen: None. E. Selvin: None.
- © 2015 by American Heart Association, Inc.