TY - JOUR
T1 - Sarcopenic obesity or obese sarcopenia
T2 - A cross talk between age-associated adipose tissue and skeletal muscle inflammation as a main mechanism of the pathogenesis
AU - Kalinkovich, Alexander
AU - Livshits, Gregory
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - Sarcopenia, an age-associated decline in skeletal muscle mass coupled with functional deterioration, may be exacerbated by obesity leading to higher disability, frailty, morbidity and mortality rates. In the combination of sarcopenia and obesity, the state called sarcopenic obesity (SOB), some key age- and obesity-mediated factors and pathways may aggravate sarcopenia. This review will analyze the mechanisms underlying the pathogenesis of SOB. In obese adipose tissue (AT), adipocytes undergo hypertrophy, hyperplasia and activation resulted in accumulation of pro-inflammatory macrophages and other immune cells as well as dysregulated production of various adipokines that together with senescent cells and the immune cell-released cytokines and chemokines create a local pro-inflammatory status. In addition, obese AT is characterized by excessive production and disturbed capacity to store lipids, which accumulate ectopically in skeletal muscle. These intramuscular lipids and their derivatives induce mitochondrial dysfunction characterized by impaired β-oxidation capacity and increased reactive oxygen species formation providing lipotoxic environment and insulin resistance as well as enhanced secretion of some pro-inflammatory myokines capable of inducing muscle dysfunction by auto/paracrine manner. In turn, by endocrine manner, these myokines may exacerbate AT inflammation and also support chronic low grade systemic inflammation (inflammaging), overall establishing a detrimental vicious circle maintaining AT and skeletal muscle inflammation, thus triggering and supporting SOB development. Under these circumstances, we believe that AT inflammation dominates over skeletal muscle inflammation. Thus, in essence, it redirects the vector of processes from “sarcopenia → obesity” to “obesity → sarcopenia”. We therefore propose that this condition be defined as “obese sarcopenia”, to reflect the direction of the pathological pathway.
AB - Sarcopenia, an age-associated decline in skeletal muscle mass coupled with functional deterioration, may be exacerbated by obesity leading to higher disability, frailty, morbidity and mortality rates. In the combination of sarcopenia and obesity, the state called sarcopenic obesity (SOB), some key age- and obesity-mediated factors and pathways may aggravate sarcopenia. This review will analyze the mechanisms underlying the pathogenesis of SOB. In obese adipose tissue (AT), adipocytes undergo hypertrophy, hyperplasia and activation resulted in accumulation of pro-inflammatory macrophages and other immune cells as well as dysregulated production of various adipokines that together with senescent cells and the immune cell-released cytokines and chemokines create a local pro-inflammatory status. In addition, obese AT is characterized by excessive production and disturbed capacity to store lipids, which accumulate ectopically in skeletal muscle. These intramuscular lipids and their derivatives induce mitochondrial dysfunction characterized by impaired β-oxidation capacity and increased reactive oxygen species formation providing lipotoxic environment and insulin resistance as well as enhanced secretion of some pro-inflammatory myokines capable of inducing muscle dysfunction by auto/paracrine manner. In turn, by endocrine manner, these myokines may exacerbate AT inflammation and also support chronic low grade systemic inflammation (inflammaging), overall establishing a detrimental vicious circle maintaining AT and skeletal muscle inflammation, thus triggering and supporting SOB development. Under these circumstances, we believe that AT inflammation dominates over skeletal muscle inflammation. Thus, in essence, it redirects the vector of processes from “sarcopenia → obesity” to “obesity → sarcopenia”. We therefore propose that this condition be defined as “obese sarcopenia”, to reflect the direction of the pathological pathway.
KW - Adipose tissue
KW - Age
KW - Inflammation
KW - Obesity
KW - Sarcopenia
KW - Sarcopenic obesity
KW - Skeletal muscle
UR - http://www.scopus.com/inward/record.url?scp=85005801887&partnerID=8YFLogxK
U2 - 10.1016/j.arr.2016.09.008
DO - 10.1016/j.arr.2016.09.008
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C2 - 27702700
AN - SCOPUS:85005801887
SN - 1568-1637
VL - 35
SP - 200
EP - 221
JO - Ageing Research Reviews
JF - Ageing Research Reviews
ER -