Association between thyroid hormone levels and frailty in an older inpatient cohort: a cross-sectional study

Frailty is a common biological syndrome in elderly people, and the aging process regulates thyroid function. The present study aimed to determine the prevalence of frailty in an older inpatient cohort using the FRAIL scale and to evaluate the association of frailty with thyroid hormone levels.

This cross-sectional study was performed in the Department of Geriatrics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China. From November 2019 to April 2020, 146 inpatients aged ≥65 years were recruited for the study and demographic data, frailty, geriatric assessment, and thyroid hormone levels were evaluated. Frailty was determined by the FRAIL scale, and geriatric assessment was based on activities of daily living (ADL) and instrumental activities of daily living (IADL). The data were analyzed using appropriate parametric and nonparametric statistical tests.

At enrollment, 31 (21.23%) of the total participants were robust, 31 (21.23%) were pre-frail, and 84 (57.53%) were frail. The frail patients were significantly older than the robust patients and pre-frail patients (P<0.001 for both). The percentages of ADL disability differed significantly among the patients for frail versus robust, frail versus pre-frail, and pre-frail versus robust, as did the percentages of IADL disability among patients for frail versus robust and frail versus pre-frail (P<0.01 for all). In binary logistic regression analyses adjusted for age, sex, body mass index, HbA1c (%), and smoking, frailty was significantly associated with serum thyroid stimulating hormone (TSH) concentration [odds ratio (OR): 1.704], T3 concentration (OR: 0.102), ADL score (OR: 0.793), and IADL score (OR: 0.413).

In our study population, the prevalence of frailty was higher in older geriatric inpatients in China than other studies. Inpatients with high TSH levels were at increased risk of frailty. Conduction of future longitudinal studies is warranted to determine the relationship between thyroid hormone levels and frailty.