SERUM THYROID-STIMULATING HORMONE LEVELSAND FRAILTY IN THE ELDERLY: THE PRO.V.A STUDY

High or low thyroid-stimulating hormone (TSH) levels seem to be associated with several negative outcomes in the elderly, but the literature about TSH and frailty is still limited. In this paper, we investigated whether TSH is associated with prevalent and incident frailty in a cohort of older community-dwelling subjects. Among 3,099 initially screened in the Progetto Veneto Anziani Study, 2,571 men and women aged >65 years (for cross-sectional analyses) and 1,732 (longitudinal, mean follow-up period of 4.4 years) were divided into sex specific quintiles according to baseline serum TSH concentrations within normal range (0.3 and 4.2 mUI/L). Frailty was defined as the presence of 3 among 5 Fried's criteria. At baseline, taking those in the third quintile of serum TSH as reference (Q3) and adjusting for potential confounders, participants in the highest (Q5) quintile, had an increased odds ratio (OR) of having frailty (OR=1.55; 95%CI: 1.03-2.33 for men; =1.97; 95%CI: 1.59-2.45 for women). Men in Q1 had a significant higher odds of having muscle weakness and exhaustion, whilst those in Q5 of muscle weakness and slow gait speed. Women in Q1 had a significant higher odds of having all the Fried's criteria (except for exhaustion), whilst those in Q5 reported a significant higher presence of muscle weakness and slow gait speed. At follow-up, men in Q5 had an increased risk of frailty (OR=1.37; 95%CI: 1.02-1.91) similarly to women in Q1 (OR=1.47; 95%CI: 1.21-1.78). In conclusion, men with higher and women lower serum TSH levels are at increased risk of frailty.