Thyroid Function Variations Within the Reference Range Do Not Affect Quality of Life, Mood, or Cognitive Function in...

Area of Science:

• Endocrinology
• Geriatric Medicine
• Neuroscience

Background:

• Thyroid function variations within reference ranges are linked to clinical outcomes.
• Impacts on quality of life, mood, and cognition from mild thyroid variations are understudied.
• Uncertainty exists regarding the neurocognitive effects of subtle thyroid function changes.

Purpose of the Study:

• To investigate the association between thyroid function within the normal range and neurocognitive outcomes.
• To determine if mild variations in thyroid-stimulating hormone (TSH) and free thyroxine (FT4) affect quality of life, mood, or cognitive function in older men.
• To assess the predictive value of baseline thyroid function on longitudinal changes in these outcomes.

Main Methods:

• Analysis of data from the Osteoporotic Fractures in Men (MrOS) Study cohort (men aged 65+).
• Included 539 euthyroid men without thyroid medication, with age-adjusted TSH within the reference range.
• Assessed quality of life, mood, and cognitive function at baseline and follow-up (n=193) over 6 years, analyzing TSH and FT4 as continuous variables.

Main Results:

• No significant associations were found between baseline TSH or FT4 levels and quality of life, mood, or cognitive function measures in 539 euthyroid men.
• Baseline thyroid function did not predict changes in quality of life, mood, or cognitive function over a mean 6-year follow-up in 193 men.
• These findings indicate no link between within-range thyroid hormone levels and neurocognitive well-being in the studied population.

Conclusions:

• Within-laboratory reference range variations in thyroid function are not associated with differences in quality of life, mood, or cognitive function.
• These results suggest that maintaining thyroid function within normal limits does not impact neurocognitive health in community-dwelling older men.
• Mild thyroid function fluctuations do not appear to be a significant factor for neurocognitive outcomes in this demographic.