Muscle Atrophy or Weakness

This study is investigating changes to the proteins in skeletal muscle that contribute to reduced muscle size and muscle function that occurs with aging.

The purpose of this study is to compare the effects of a standardized Traditional Chinese Medicine (TCM) formula versus beta-hydroxy-beta-methylbutyrate (HMB) on muscle strength and bone health in pre-frail older adults . Pre-frailty is a critical stage where functional decline may still be reversed through proper intervention. The study will enroll 90 participants aged 65 years or older who meet the criteria for pre-frailty. Participants will be randomly assigned to either the TCM group (receiving a standardized herbal powder formula) or the HMB group (receiving nutritional supplement tablets) for 24 weeks . The primary objective is to evaluate the change in handgrip strength from baseline to Week 12 . Researchers will also assess changes in skeletal muscle mass, bone mineral density, and overall physical performance . The goal is to determine if the TCM formula is an effective alternative or complementary intervention for managing geriatric frailty.

A hallmark of aging is an impaired ability to adequately recover following a stressor, such as muscle disuse, resulting in muscle fibrosis and weakness thereby increasing the risk for falls and loss of independence. Mechanistic-based therapeutic strategies to enhance muscle recovery in older adults do not exist. Metformin has been implicated to have positive effects on muscle size and function through non-glycemic mechanisms. Metformin has been shown to enhance macrophage function and lessen cellular senescence burden by targeting SASP in a variety of muscle interstitial cells. However, the role of metformin to improve muscle recovery in older adults following disuse atrophy through immunomodulating and senomorphic mechanisms have not been examined. Therefore, the purpose of this study is to conduct a randomized, double blind, placebo-controlled clinical trial in older adult participants to determine if short-term metformin delivery (vs placebo) during the recovery phase following disuse atrophy can improve muscle regrowth.

The aim of this clinical trial is to evaluate the effectiveness of Medium-Frequency Neuromuscular Electrical Stimulation, in combination with standard physical therapy, compared to standard physical therapy alone, on muscle mass, muscle strength, and functionality in critically ill patients aged 80 and over during their hospital stay. The safety of the intervention and the standardization of protocol parameters will also be assessed. The main research questions are: * Does the implementation of a standardized Medium-Frequency Neuromuscular Electrical Stimulation protocol, in combination with standard physical therapy, compared to standard physical therapy alone, help attenuate the loss of skeletal muscle mass, strength, and functionality in critically ill patients aged 80 and over? * Is the use of this protocol and its proposed parameters safe for critically ill patients aged 80 and over? The study will consist of applying a standardized Medium-Frequency Neuromuscular Electrical Stimulation protocol to oldest old patients admitted to the Intensive Care Unit of Dr. Hernán Henríquez Aravena Hospital in Temuco, Chile. The sample will consist of oldest old participants (≥80 years), who will be randomly divided into two subgroups: a control group that will receive standard physical therapy typically provided during hospitalization, and an experimental group that will receive the same standard therapy plus Medium-Frequency Neuromuscular Electrical Stimulation, which will begin within the first 48 hours of Intensive Care Unit admission. The following variables will be assessed in both groups (control and experimental), from Intensive Care Unit admission to hospital discharge: * Skeletal muscle mass characteristics and evolution (quadriceps femoris and anterior tibialis muscle thickness), measured by ultrasonography. * Handgrip strength, measured using a digital hand dynamometer. * Inspiratory muscle strength, assessed using a pimometer. * Peripheral muscle strength, evaluated with the Medical Research Council Sum Score (MRC-SS). * Functionality, assessed by the Functional Status Score for the Intensive Care Unit (FSS-ICU) . * Independence in basic activities of daily living, measured using the Barthel Index. * Quality of life, evaluated using the Short Form-36 Health Survey (SF-36). * Cognitive impairment, assessed through the Montreal Cognitive Assessment (MoCA). * Frailty, measured using the Clinical Frailty Scale (CFS).