Pathophysiology and mechanisms of primary sarcopenia (Review)

Abstract

Aging causes skeletal muscle atrophy, and myofiber loss can be a critical component of this process. In 1989, Rosenberg emphasized the importance of the loss of skeletal muscle mass that occurs with aging and coined the term 'sarcopenia'. Since then, sarcopenia has attracted considerable attention due to the aging population in developed countries. The presence of sarcopenia is closely related to staggering, falls and even frailty in the elderly, which in turn leads to the need for nursing care. Sarcopenia is often associated with a poor prognosis in the elderly. Therefore, it is crucial to investigate the causes and pathogenesis of sarcopenia, and to develop and introduce interventional strategies in line with these causes and pathogenesis. Sarcopenia can be a primary component of physical frailty. The association between sarcopenia, frailty and locomotive syndrome is complex; however, sarcopenia is a muscle-specific concept that is relatively easy to approach in research. In the elderly, a lack of exercise, malnutrition and hormonal changes lead to neuromuscular junction insufficiency, impaired capillary blood flow, reduced repair and regeneration capacity due to a decrease in the number of muscle satellite cells, the infiltration of inflammatory cells and oxidative stress, resulting in muscle protein degradation exceeding synthesis. In addition, mitochondrial dysfunction causes metabolic abnormalities, such as insulin resistance, which may lead to quantitative and qualitative abnormalities in skeletal muscle, resulting in sarcopenia. The present review article focuses on age-related primary sarcopenia and outlines its pathogenesis and mechanisms.

Prognostic Impact of the SARC-F Score in Gastrointestinal Advanced Cancers

“…Sarcopenia is characterized by generalized muscle mass loss and muscle functional decline, leading to physical frailty, cachexia, and mortality [ 1 , 2 ]. Malnutrition, reticence, advanced malignancy burden, and persistent inflammatory condition often identified in patients with gastrointestinal disorders are typical clinical characteristics associated with sarcopenia [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ].…”

Comparison of SARC-F Score among Gastrointestinal Diseases

“…More than three decades have passed since Rosenberg first proposed the concept of sarcopenia in 1989 [24]. In the field of public health, sarcopenia has been attracting much caution these days due to its close association with prognosis (e.g., falls, fracture, infection, frailty and survival) [1][2][3][4][5][6][7]10]. To diagnose sarcopenia, it is necessary to assess muscle mass, but computed tomography and bioelectrical impedance analysis for muscle mass assessment are often not available in small clinics [16].…”

“…The median (IQR) SARC-F score in these 66 patients was 0 (0-0), and the proportion of patients with SARC-F ≥4 points was 6.1% (4/66). Sarcopenia contemporaneous with gastrointestinal diseases can be complicated by primary factors due to aging and secondary factors due to the disease burden itself [2,7,10]. Nutritional aspects and inflammatory aspects are both relevant for the incidence of sarcopenia [29].…”

“…Sarcopenia is a clinical symptom characterized by progressive and generalized loss of muscle mass and muscle functional weakness that results in frailty, cachexia, severe infection, osteoporosis, and thereby all-cause mortality [1,2]. Inactivity in daily life, bedridden status, malnutrition, advanced cancer-bearing conditions, and chronic inflammatory conditions frequently seen in patients with gastrointestinal diseases are typical clinical features leading to sarcopenia [1][2][3][4][5][6][7][8][9].…”

“…Sarcopenia is a clinical symptom characterized by progressive and generalized loss of muscle mass and muscle functional weakness that results in frailty, cachexia, severe infection, osteoporosis, and thereby all-cause mortality [1,2]. Inactivity in daily life, bedridden status, malnutrition, advanced cancer-bearing conditions, and chronic inflammatory conditions frequently seen in patients with gastrointestinal diseases are typical clinical features leading to sarcopenia [1][2][3][4][5][6][7][8][9]. Alterations in nutritional metabolism, nutritional requirements, and reduced dietary intakes are also often encountered in patients with gastrointestinal diseases [8], and sarcopenia in patients with gastrointestinal diseases can be associated with worse patient QOL, poorer prognosis, and more expensive health care costs [8,10].…”