[Thyroid function in the euthyroid elderly subject: evidence of low T3 syndrome]

Area of Science:

• Endocrinology
• Geriatric Medicine
• Thyroidology

Context:

• Aging is associated with numerous physiological changes.
• Thyroid hormones play a crucial role in metabolism and overall health.
• Distinguishing normal age-related thyroid function from pathological conditions is clinically important.

Purpose:

• To investigate the prevalence and characteristics of low T3 syndrome in elderly euthyroid individuals.
• To compare thyroid function indices between elderly subjects and younger adults.
• To identify specific thyroid hormones affected in the elderly population.

Summary:

• A study confirmed the presence of low T3 syndrome in elderly euthyroid patients (n=133, age >65).
• This condition is defined by lower circulating total triiodothyronine (TT3) and free triiodothyronine (FT3) levels compared to younger adults (n=204, age 18-65).
• Statistical analysis revealed that only TT3 and FT3 levels were significantly reduced in the elderly group, indicating age-specific alterations in thyroid hormone status.

Impact:

• Provides evidence for a distinct thyroid function profile in the elderly, termed low T3 syndrome.
• Contributes to a better understanding of age-related endocrine changes.
• May inform clinical practice regarding the interpretation of thyroid function tests in older adults.