We’ve seen several papers in which it is claimed that it is entirely normal for older people to have higher TSH and lower thyroid hormone levels than younger people.
Definition of older (or aged or whatever term they use) varies, but I think we can probably assume most mean at least 65.
While this paper doesn’t entirely reverse that, it does at least identify that higher TSH is associated with higher risk of “frailty”. In my mind, that implies that assumptions of higher TSH could be entirely wrong-headed. If nothing else, the issues appear not to be as settled as might be claimed by some.
Thyroid hormones and frailty in older adults: systematic review and dose–response meta-analysis
Wen-Chun Chia, Yang-Ching Chen, Shuang-ling Xiu & Sen-Te Wang
BMC Geriatrics volume 25, Article number: 104 (2025)
Abstract
Objective
To investigate (1) whether the association of thyroid hormone with frailty risk is linear or nonlinear and (2) which range of thyroid hormones or thyroid stimulating hormone (TSH) is more associated with a higher risk of frailty in older adults.
Design
Systematic review and dose–response meta-analysis.
Methods
Medical electronic databases were searched for cross-sectional or longitudinal studies, published from database inception to February 2022. We focused on the relationship between TSH and frailty. Data on TSH reference range, TSH exposure categories, sample size of each exposure category, and adjusted odds ratios (ORs) for frailty with 95% confidence interval (CI) were extracted. In the dose–response meta-analysis, we set the OR for frailty as 1 at 0.3 mIU/L TSH.
Results
The systematic review included 10 studies, whereas the meta-analysis included 3 studies (n = 6388). TSH levels ranged from 0.3 to 4.8 mIU/L, and the dose–response meta-analysis revealed a significant J-shaped association (p = 0.0071). Frailty OR (95% CI) increased from 1.30 (1.06–1.59) for 2.7 mIU/L TSH to 2.06 (1.18–3.57) for 4.8 mIU/L TSH.
Conclusions
A significant nonlinear, J-shaped association was noted between TSH level and frailty. TSH levels within the upper half (2.7–4.8mIU/L) of reference range was noted to significantly higher risk of frailty; by contrast, those in the lower half (0.6–1.5 mIU/L) had a lower risk of frailty, though not significantly so.
Trail registration
This systematic review was registered with PROSPERO (registration number: CRD42022299214).