Sarcopenia and probable sarcopenia are associated with loss of muscle strength, functional impairment, frailty, and an increased risk of adverse outcomes in older adults. In short-term interventions, structural or functional changes may be modest, whereas certain serum biomarkers of metabolic-nutritional response may be more sensitive. In this protocol version, serum transthyretin (TTR) has been selected as the primary outcome, without assuming that it represents, by itself, a direct measure of muscle mass or overall clinical efficacy.
Age between 60 and 80 years at the time of enrollment.
Ability to understand the study procedures and provide written informed consent.
SARC-F score ≥4 during screening.
Reduced muscle strength defined as handgrip strength <27 kg in men or <16 kg in women; alternatively, a time >15 seconds on the five-repetition chair stand test when handgrip dynamometry cannot be validly performed or is contraindicated.
Cognitive impairment according to the abbreviated Mini-Mental State Examination (MMSE), using the operational cutoff approved for the study (≤13 points).
Clinically significant chronic liver disease, clinically significant chronic kidney disease, nephrotic syndrome, active cancer or recent oncological treatment, or any condition that may substantially affect serum TTR levels or increase participant risk.
Acute infection, acute inflammatory condition, or clinical decompensation at baseline that may interfere with the interpretation of serum TTR measurements.
Uncontrolled diabetes mellitus or any metabolic condition that, in the investigator's judgment, may increase the risks associated with the intervention.