Non-thyroidal illness syndrome and short-term survival in a hospitalised older population

non-thyroidal illness syndrome (NTIS) has been associated with an adverse clinical outcome.

to evaluate the prevalence of NTIS, its impact on patients' survival and the possible pathogenic role of systemic inflammation.

observational cross-sectional analysis.

three hundred and one acutely ill older patients (156 women; median age 81 years, range 65-101) consecutively admitted to a primary care unit.

serum FT(3), FT(4) and thyrotropin levels as well as acute inflammation indexes were evaluated.

the NTIS prevalence (specifically low T3 syndrome) was 31.9%. A significant association was found between NTIS and acute renal failure (P = 0.006), New York Heart Association classification (NYHA) IV heart failure (P = 0.003) and metastasised cancer disease (P = 0.0002). Serum FT(3) values correlated inversely with serum C-reactive protein (P < 0.0001), lactate dehydrogenase (P = 0.0004), fibrinogen (P = 0.03) and erythrocyte sedimentation rate (P < 0.0001) values, and progressively decreased with increasing tertiles of age (P = 0.0004). The mortality rate was significantly higher (P = 0.0002) among patients with low T3 syndrome, which emerged as the sole predictive factor of death (odds ratio 4.3; 95% confidence interval 1.7-10.5).

low T3 syndrome is very common in the hospitalised older population, emerging as the most sensitive independent predictor of short-term survival. Serum FT(3) determination should be included in the assessment of short-term prognosis of acutely ill older patients.