Thyroid Function, Cardiovascular Risk Factors, and Incident Atherosclerotic Cardiovascular Disease: The Atherosclerosis Risk in Communities (ARIC) Study.

Thyroid Function, Cardiovascular Risk Factors, and Incident Atherosclerotic Cardiovascular Disease: The Atherosclerosis Risk in Communities (ARIC) Study.

J Clin Endocrinol Metab. 2017 Jun 12;:

Authors: Martin SS, Daya N, Lutsey PL, Matsushita K, Fretz A, McEvoy JW, Blumenthal RS, Coresh J, Greenland P, Kottgen A, Selvin E

Abstract
Context: Cardiovascular outcomes in mild thyroid dysfunction (treatment controversial) and moderate or severe dysfunction (treatment standard) remain uncertain.
Objective: To examine cross-sectional and prospective associations of thyroid function with cardiovascular risk factors and events.
Design: In the Atherosclerosis Risk in Communities (ARIC) Study, we measured concentrations of thyrotropin (TSH), free thyroxine (FT4), and total triiodothyronine (T3) in stored serum samples originally collected in 1990-92. We used multivariable linear regression to assess cross-sectional associations of thyroid function with cardiovascular risk factors and Cox regression to assess prospective associations with cardiovascular events. Follow-up occurred through 12/31/14.
Setting: General community.
Participants: Black and white men and women from the US, without prior myocardial infarction, stroke, or heart failure.
Main Outcomes and Measures: Cross-sectional outcomes were blood pressure, glycemic markers, and blood lipids. Prospective outcomes were adjudicated fatal and non-fatal myocardial infarction and stroke.
Results: Among 11,359 participants (57±6 years, 58% women), thyroid function was more strongly associated with blood lipids than blood pressure or glycemic measures. Mean adjusted differences in LDL-C were +15.1 (95%CI 10.5-19.7) and +3.2 (0.0-6.4) mg/dL in those with moderate/severe and mild chemical hypothyroidism, relative to euthyroidism; an opposite pattern was seen in hyperthyroidism. Similar differences were seen in triglycerides and non-HDL-C. With 22.5 year median follow-up, 1,102 myocardial infarctions and 838 strokes occurred, with similar outcomes among baseline thyroid function groups and by T3 concentrations.
Conclusions: Hypothyroidism is associated with hyperlipidemia, but the magnitude is small in mild chemical hypothyroidism, and cardiovascular outcomes are similar between thyroid function groups.

PMID: 28605456 [PubMed - as supplied by publisher]

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