Thyroid Hormones Predict Mortality Risk in Elderly

Thyroid hormone levels, especially low free triiodothyronine (FT3), can help to predict risk of death in older patients hospitalized after an acute illness.

Pedro Iglesias, MD, of Hospital Ramon y Cajal in Madrid, and colleagues followed 404 patients with average age of 85.9 years admitted to the hospital for acute illness in 2005. Follow-up was 7 years. Using thyroid function tests, researchers measured the patients’ levels of thyroid hormones.

Of the 404, 61 patients died in the hospital and 262 died within the 7 years. Of the 61 inpatient deaths, 52 (85.2%) had low levels of FT3 at time of measurement. Of the 262 who died in the 7 years of follow-up, researchers found that 170 (64.9%) had shown low levels of FT3 at time of measure.

Only 9 of the 144 patients with normal FT3 levels at the beginning of the study died in the hospital.

"When older individuals have low levels of thyroid hormones, particularly T3, it reflects that the body is weak and more susceptible to the harmful effects of disease,” researchers said. "As a result, older individuals who have a reduced ability to synthesize T3 hormones have a higher rate of mortality, both in the short- and long-term.”

–Michael Potts

Reference:

Iglesias P, Ridruejo E, Munoz A, et al. Thyroid function tests and mortality in aged hospitalized patients: a 7-year prospective observational study [published online October 30, 2013]. J Clin Endocrinol Metabol. doi:10.1210/jc.2012-3849.