Researchers from the University of Michigan report that older adults exposed to low levels of thyrotropin, whether caused by natural thyroid activity or external thyroid hormone influence, show a higher likelihood of developing cognitive impairment. The finding appears in a study that adds to the growing body of knowledge about how thyroid hormone levels can affect brain function over time.
Thyrotoxicosis is a medical condition defined by an excess of thyroid hormones in the bloodstream. When these hormones rise, they can disrupt multiple body systems and their functions. People may notice dry skin, hair that becomes brittle, puffiness around the face, and subtle tremors in the eyelids or hands, which can extend to the entire body. Temperature regulation can become erratic, nervousness and irritability may increase, sweating can intensify, and the person might feel unusually warm or restless. These signs reflect the broader impact that hormone imbalance can have on daily comfort and overall health.
The investigation included a large cohort of 65,000 adults aged 65 and older. The researchers observed that by the age of 75, the rate of cognitive impairment was 11% among those with thyrotoxicosis exposure compared with 6.4% among those without exposure. When looking across all ages in the study, thyroid hormone excess from any cause was linked to a heightened risk of various cognitive problems, suggesting that thyroid balance plays a meaningful role in maintaining cognitive function through the years.
One of the study authors noted that an elevated risk of cognitive decline is a possible adverse outcome associated with too much thyroid hormone. This is particularly relevant for patients who receive thyroid hormone therapy, underscoring the need for careful monitoring and individualized treatment plans to balance benefits against potential cognitive risks.
Historically, researchers have also explored strategies to lower cardiovascular complications that can accompany thyroid disorders. Ongoing investigations continue to seek therapies that mitigate these risks while preserving effective control of thyroid hormone levels, highlighting the importance of comprehensive care for older adults facing thyroid-related health challenges.