Relationship Between Circulating Thyroid-Stimulating Hormone, Free Thyroxine, and Free Triiodothyronine Concentrations and 9-Year Mortality in Euthyroid Elderly Adults

J Am Geriatr Soc. 2016 Mar;64(3):553-60. doi: 10.1111/jgs.14029.


Objectives: To determine the association between plasma thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels and all-cause mortality in older adults who had levels of all three hormones in the normal range.

Design: Longitudinal.

Setting: Community-based.

Participants: Euthyroid Invecchiare in Chianti study participants aged 65 and older (N = 815).

Measurements: Plasma TSH, FT3, and FT4 levels were predictors, and 9-year all-cause mortality was the outcome. Cox proportional hazards models adjusted for confounders were used to examine the relationship between TSH, FT3, and FT4 quartiles and all-cause mortality over 9 years of follow-up.

Results: During follow-up (mean person-years 8,643.7, range 35.4-16,985.0), 181 deaths occurred (22.2%). Participants with TSH in the lowest quartile had higher mortality than the rest of the population. After adjusting for multiple confounders, participants with TSH in the lowest quartile (hazard ratio = 2.22, 95% confidence interval = 1.19-4.22) had significantly higher all-cause mortality than those with TSH in the highest quartile. Neither FT3 nor FT4 was associated with mortality.

Conclusion: In elderly euthyroid subjects, normal-low TSH is an independent risk factor for all-cause mortality.

Keywords: elderly; euthyroid; mortality.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cause of Death
  • Euthyroid Sick Syndromes / blood*
  • Euthyroid Sick Syndromes / mortality*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Proportional Hazards Models
  • Reference Values
  • Risk Factors
  • Thyroid Function Tests
  • Thyrotropin / blood*
  • Thyroxine / blood*
  • Triiodothyronine / blood*


  • Triiodothyronine
  • Thyrotropin
  • Thyroxine