Thyroid Dysfunction Increases Frailty Risk in Older Adults

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Recent research suggests that thyroid dysfunction plays a significant role in frailty among older adults.

Frailty, which is the deterioration in adaptive capacity caused by a regression of the body systems, makes individuals more vulnerable to falls, illness, hospitalization and even death. The condition also increases the risk of depression and malnutrition — both of which significantly impact a person’s quality of life.

“While studies have investigated the relationship between frailty and various conditions in the geriatric population — such as cardiovascular diseases, chronic kidney disease and cancer — research on the association between thyroid dysfunction and frailty is limited,” wrote a team of Turkish investigators.

To assess how thyroid function influences frailty in people aged 65 and older, investigators evaluated 220 adults with thyroid dysfunction — some receiving treatment, some not — who visited the Internal Medicine, Endocrinology and Geriatrics outpatient clinics at Ankara Training and Research Hospital between December 2019 and December 2020.

They measured several thyroid hormones, including thyroid-stimulating hormone (TSH), free triiodothyronine (fT3) and free thyroxine (fT4), along with thyroid peroxidase antibodies (anti-TPO). Frailty was analyzed using the Study of Osteoporotic Fractures (SOF) scale, the Edmonton Frail Scale (EFS) and the FRAIL scale. These measure weight loss, physical weakness, falls, physical and mental health, fatigue, ambulation and illness. Information on demographics, comorbidities, medication use, physical examination, medical history and urinary incontinence was also collected.

The median age of the patients was 73 years, and most (68.2%) were women. The most common comorbidities were hypertension and diabetes (64.1% and 46.4%, respectively). Urinary incontinence was observed in 42.3% of patients, and 28.6% were anti-TPO positive.

Overall, older adults with thyroid hormone levels outside of the normal range — defined as a TSH value between 0.5 and 6 mIU/L — were more likely to be frail. According to the FRAIL scale, increased frailty was significantly linked to lower fT3 levels.

Frailty was also impacted by factors such as age, gender, education, medication use and the presence of other chronic diseases.

For those aged 80 and older, a low fT3/fT4 ratio was consistently tied to frailty, and for those under 80, low levels of TSH — a hormone that regulates thyroid activity — were more strongly linked to frailty, especially when assessed using the FRAIL scale. These results support using age-specific TSH ranges, particularly for patients over 80, to help manage frailty and provide tailored treatment for thyroid issues.

Investigators encourage routine thyroid tests as part of frailty assessments, especially when looking at age-specific hormone levels. By identifying thyroid problems early, doctors may be able to take steps to reduce frailty and improve quality of life in older adults.

Using three separate validated frailty scales was mentioned as a strength of the study, as they allowed investigators to explore frailty more broadly. Further, identifying fT3 and the fT3/fT4 ratio as potential biomarkers for frailty adds to the body of evidence supporting the incorporation of thyroid function assessments into frailty screening practices.

However, investigators noted the cross-sectional design and single-center nature of the data as limitations. Additionally, the small sample size may have hindered the generalizability of the results. As thyroid function was based on a single measurement, they advise future researchers to use multiple measures over time to better understand thyroid function and its connection to frailty, as well as incorporate a larger, more diverse patient population to confirm associations and establish causality.

“These findings emphasize the multidimensional effects of thyroid function during aging and underscore the necessity of individualized clinical approaches,” investigators concluded.