Serum Thyroid-Stimulating Hormone Levels and Frailty in the Elderly: The Progetto Veneto Anziani Study

Abstract

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 article, we investigated whether TSH is associated with prevalent and incident frailty in a cohort of older community-dwelling subjects. Among 3099 initially screened in the Progetto Veneto Anziani Study, 2571 men and women aged ≥65 years (for cross-sectional analyses) and 1732 (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 three among five 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% confidence interval [CI]: 1.03-2.33 for men; OR = 1.97; 95% CI: 1.59-2.45 for women). Men in Q1 had significant higher odds of having muscle weakness and exhaustion, while those in Q5 had muscle weakness and slow gait speed. Women in Q1 had significantly higher odds of having all the Fried's criteria (except for exhaustion), while those in Q5 reported a significantly 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) similar to women in Q1 (OR = 1.47; 95% CI: 1.21-1.78). In conclusion, men with higher and women with lower serum TSH levels are at increased risk of frailty. © Copyright 2017, Mary Ann Liebert, Inc. 2017.