Subclinical thyroid dysfunction does not appear to be linked to cognitive decline, according to a large study.

The finding calls into question the practice of screening for subclinical thyroid dysfunction intended to avert cognitive decline or dementia, the Dutch-led researchers say.

They evaluated cross-sectional and longitudinal associations between baseline thyroid dysfunction and cognitive function and dementia using individual patient data from 23 cohorts including nearly 75,000 participants.

One of the included cohorts was the Australian Health in Men study, the investigators reported in JAMA Internal Medicine.