Rev Bras Fisiol Exerc 2022;21(2):90-1

doi: 10.33233/rbfex.v21i2-5218

EDITORIAL

Is there a causal relationship between sarcopenia and dynapenia in patients undergoing bariatric surgery?

Luji Iseki Takenami, Felipe Nunes Almeida Santos, Clarcson Plácido Conceição dos Santos

Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brazil

Luji Iseki Takenami: lujitakenami20.1@bahiana.edu.br

Felipe Nunes Almeida Santos: felipesantos 17.1@bahiana.edu.br

Clarcson Plácido C. dos Santos: clarcson@hotmail.com

Sarcopenia is defined, in the Greek language, as “poverty of the flesh” and, at first, it was treated as the natural process of aging related to the decline of the lean mass [1]. This concept, however, is still not established. Some authors limit sarcopenia only to the loss of lean mass, others also associate it with loss of muscle strength - called dynapenia - unifying the two concepts [2]. Furthermore, sarcopenia is not only linked to the aging process, as it involves a multifactorial system such as obesity, for example.

Obesity is a global epidemic condition of significant social and economic impact that can lead to chronic diseases, functional limitations, high risk of mortality, and, when associated with the diagnosis of sarcopenia, is called sarcopenic obesity [3]. Obese patients have a greater amount of muscle mass and strength compared to non-obese individuals and morphological changes such as weight loss generally have repercussions on the decrease in lean mass, causing sarcopenia (SO) [3].

The European Working Group on Sarcopenia in Older People (EWGSOP) is responsible for the currently most used guideline for the diagnosis and grading of sarcopenia [1]. The muscular strength with the handgrip test, the volume of lean mass with the study of bioimpedance, and the gait speed in the walking test, also applied in the Short Physical Performance Battery (SPPB), are the evaluated parameters, being possible to grade the sarcopenia in pre -sarcopenia, sarcopenia and severe sarcopenia [1,2]. The guideline EWGSOP2, an updated version of EWGSOP, uses the sit-to-stand test (SST) as a muscle strength parameter, evaluating the speed of the individual in getting up from a chair [3].

In a recent study, women undergoing bariatric surgery in a period of weight stability, when compared with women with SO who did not undergo the same surgery, performed better on the SST and SPPB [3]. In another study, it was estimated that the prevalence of SO in the elderly (≥ 60 years) in the world was 15% when the diagnosis of sarcopenia was based only on the volume of lean mass and decreased to 4% when muscle strength and physical functionality were considered [4]. These results refer to the possibility of the current guidelines are neglecting the influence of body fat index, in addition to raising the hypothesis that there is no causal relationship between sarcopenia and dynapenia.

The Figure 1 presents a working model for one of the current perceptions about the etiological multifactorial system of dynapenia in the elderly. The hypothesis to be tested is the inexistence of a causal relationship between sarcopenia and dynapenia and to investigate other factors capable of influencing more significantly, such as body fat index, the outcome of dynapenia in obese individuals.

The understanding of the multifactorial system that involves the development of sarcopenia and dynapenia, the elucidation of their concepts, and the understanding of the nature of the causal relationship between the two conditions can work in the prevention of motor dysfunction in obese and elderly individuals and improve the quality of life for this population.

Figure 1 – Working model created by Clark & Manini [5] to explore the multifactorial biological mechanisms that may influence the loss of muscle strength in the elderly

References

1. Delmonico MJ, Beck DT. The current understanding of sarcopenia: Emerging tools and interventional possibilities. American Journal of Lifestyle Medicine 2017;11:167-81. doi: 10.1177/1559827615594343 [Crossref]
2. Silva TA, Duarte YAO, Santos FJL, Wong R, Lebrão ML. Sarcopenia according to the European working group on sarcopenia in older people (EWGSOP) versus Dynapenia as a risk factor for disability in the elderly. J Nutr Health Aging 2014;18(5):547-53. doi: 10.1007/s12603-014-0465-9 [Crossref]
3. Buzza AFB, Machado CA, Pontes F, Sampaio LG, Contador JS, Sampaio CL, et al. Prevalence of sarcopenia in women at stable weight phase after Roux-en-Y gastric bypass. Arch Endocrinol Metabol 2022. doi: 10.20945/2359-3997000000494 [Crossref]
4. Gao Q, Mei F, Shang Y, Hu K, Chen F, Zhao L, et al. Global prevalence of sarcopenic obesity in older adults: A systematic review and meta-analysis. Clin Nutr 2021;40(7):4633-41. doi: 10.1016/j.clnu.2021.06.009 [Crossref]
5. Clark BC, Manini TM. Functional consequences of sarcopenia and dynapenia in the elderly. Curr Opin Clin Nutr Metab Care 2010;13(3):271-6. doi: 10.1097/MCO.0b013e328337819e [Crossref]