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

J Clin Endocrinol Metab. 2017 Sep 1;102(9):3306-3315. doi: 10.1210/jc.2017-00986.


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 Study, we measured concentrations of thyrotropin, free thyroxine, and total triiodothyronine (T3) in stored serum samples originally collected in 1990-1992. 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 31 December 2014.

Setting: General community.

Participants: Black and white men and women from the United States, without prior myocardial infarction (MI), 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 nonfatal MI 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 low-density lipoprotein cholesterol were +15.1 (95% confidence interval: 10.5 to 19.7) and +3.2 (0.0 to 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-high-density lipoprotein cholesterol. With a 22.5-year median follow-up, 1102 MIs 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.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Distribution
  • Aged
  • Atherosclerosis / diagnosis
  • Atherosclerosis / epidemiology*
  • Cardiovascular Diseases / diagnosis
  • Cardiovascular Diseases / epidemiology*
  • Cohort Studies
  • Comorbidity
  • Confidence Intervals
  • Cross-Sectional Studies
  • Female
  • Humans
  • Hyperthyroidism / diagnosis
  • Hyperthyroidism / epidemiology
  • Hypothyroidism / diagnosis
  • Hypothyroidism / epidemiology
  • Incidence
  • Male
  • Middle Aged
  • Prognosis
  • Proportional Hazards Models
  • Prospective Studies
  • Risk Assessment
  • Severity of Illness Index
  • Sex Distribution
  • Survival Analysis
  • Thyroid Diseases / diagnosis
  • Thyroid Diseases / epidemiology*
  • Thyroid Diseases / therapy*
  • Thyroid Function Tests
  • United States / epidemiology