How are TSH and Langlebigkeit related?

The relationship between TSH (thyroid-stimulating hormone) and longevity is complex and not fully resolved. Observational studies suggest a U-shaped association: both low TSH (subclinical hyperthyroidism) and high TSH (subclinical hypothyroidism) may increase mortality risk in middle-aged adults. However, in the very old (≥80 years), slightly elevated TSH levels have been linked to lower mortality, a phenomenon sometimes called the 'protective phenotype.' This is supported by the Leiden Longevity Study and NHANES analyses, but evidence remains observational and confounded by age, sex, and comorbidities. No RCTs have tested whether modulating TSH extends lifespan. Furthermore, TSH alone is a poor predictor of longevity without free T3/T4 and clinical context. In summary, while a mildly elevated TSH in older age may correlate with longevity, the evidence is moderate and not actionable for individual health decisions. Thyroid function should be assessed holistically by a physician.