Sarcopenic obesity in older adults: aetiology, epidemiology and treatment strategies

Abstract

The prevalence of obesity in combination with sarcopenia (the age-related loss of muscle mass and strength or physical function) is increasing in adults aged 65 years and older. A major subset of adults over the age of 65 is now classified as having sarcopenic obesity, a high-risk geriatric syndrome predominantly observed in an ageing population that is at risk of synergistic complications from both sarcopenia and obesity. This Review discusses pathways and mechanisms leading to muscle impairment in older adults with obesity. We explore sex-specific hormonal changes, inflammatory pathways and myocellular mechanisms leading to the development of sarcopenic obesity. We discuss the evolution, controversies and challenges in defining sarcopenic obesity and present current body composition modalities used to assess this condition. Epidemiological surveys form the basis of defining its prevalence and consequences beyond comorbidity and mortality. Current treatment strategies, and the evidence supporting them, are outlined, with a focus on calorie restriction, protein supplementation and aerobic and resistance exercises. We also describe weight loss-induced complications in patients with sarcopenic obesity that are relevant to clinical management. Finally, we review novel and potential future therapies including testosterone, selective androgen receptor modulators, myostatin inhibitors, ghrelin analogues, vitamin K and mesenchymal stem cell therapy.

Obesity and ageing: Two sides of the same coin

“…Similar to ageing, obesity triggers the infiltration of fat into muscle, which could be a cause of early development of sarcopenia as the intramuscular lipid droplets hinder the regeneration potential and function of skeletal muscle. 156 Besides the muscular force, muscular endurance is negatively associated with BMI, 157 which is also a characteristic of sarcopenia. 158 Interestingly, subcutaneous fat does not appear to induce muscle wasting to the same extent as visceral fat.…”

Relative sarcopenia and mortality and the modifying effects of chronic kidney disease and adiposity

“…Sarcopenic obesity is defined as the presence of both obesity and sarcopenia in an individual. The prevalence varies based on the criteria used to define sarcopenia and obesity . Most studies use % body fat (%BF) to define obesity .…”

“…The prevalence varies based on the criteria used to define sarcopenia and obesity . Most studies use % body fat (%BF) to define obesity . This definition of obesity is problematic in the context of sarcopenia, as lower muscle mass results in a greater %BF in two individuals with the same fat mass.…”

“…45,51 Most studies use % body fat (%BF) to define obesity. 13,44,45,51 This definition of obesity is problematic in the context of sarcopenia, as lower muscle mass results in a greater %BF in two individuals with the same fat mass. In our study, only 18 individuals met criteria for both sarcopenia and obesity when FMI was used to define obesity.…”

Cancer‐ and Chemotherapy‐Induced Musculoskeletal Degradation

“…Among patients with solid tumors of the respiratory or gastrointestinal systems, 15% of obese patients (BMI >30 kg/m 2 ) were sarcopenic . To place the prevalence of sarcopenia during cancer into context, the prevalence in the general population (defined as: [(Appendicular Skeletal Muscle Mass)/BMI] <0.512 for women, or <0.789 for men) is 12% or 34% in women and men of all ages, and 48% or 27.5% among women and men older than 80 years . Comparison of prevalence among cancer patients and the general population suggests that sarcopenia may be more prevalent among cancer patients, though direct comparisons have yet to be made.…”