This article is more than 5 years old. Information may no longer be current.
Low thyroid levels increased mortality risk among hospitalized elderly patients
Alterations in thyroid function test results during hospitalization were associated with long-term mortality in elderly patients, and low triiodothyronine levels were closely associated with all-cause and cardiovascular mortality, according to study results.
“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,” Pedro Iglesias, MD, of Hospital Ramón y Cajal in Madrid, said in a press release. “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.”
Iglesias and colleagues looked at 404 patients older than 65 years who were admitted to the Hospital General in Segovia, Spain, in 2005. These included patients admitted to the department of geriatrics for any reason, but excluded those taking medications that altered thyroid levels.
These patients underwent measurements of their thyroid-stimulating hormone, free thyroxine and free T3 on their first day of hospitalization; 73% of patients had abnormal thyroid function test results. Researchers followed the patients until Jan. 1, 2012, registering total survival times, number of deaths, and all-cause and CV mortality.
During the course of the study, 80% of the patients died (n=323) and data showed that median survival time for all-cause mortality was lower in patients in the first tertile of serum free T3, the first tertile of TSH and the first tertile of serum free T4.
Adjusted analysis associated all-cause mortality with a history of cancer (HR=1.6; 95% CI, 1.12-2.28), age (HR=1.03; 95% CI 1.01-1.06) and free T3 levels (HR=0.72; 0.63-0.84).
Death during hospitalization accounted for 61 patients (15.1%). Conversely, only nine of the 144 patients with normal thyroid levels (6.2%) died during hospitalization, “making that finding highly predictive of survival,” the researchers wrote.
Of those patients in whom cause of death was known (n=202), 30.2% were listed as CVD. In a regression analysis, free T3 was a predictor of CV mortality (HR=0.76; 95% CI, 0.63-0.91).
“T3 could be a useful measure for gauging an older individual’s chances of surviving an acute illness requiring hospitalization,” Iglesias said. “The reduced ability to synthesize the hormone observed in this group of patients could be related to the severity of the disease and its prognosis.”
Disclosure: The researchers report no relevant financial disclosures.
Collapse