Associação entre sarcopenia e obesidade sarcopênica com variáveis inflamatórias em mulheres idosas

Introduction: Aging is a process that leads to a progressive decline in the function of all physiological systems and is associated with the development of inflammation. The cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα), as well as the C-reactive protein (CRP) are important inflammatory markers related to aging. Changes in body composition such as reduced fat free mass (FFM) and increased fat mass (FM) are also characteristics of aging. The progressive loss of FFM and the concomitant reduction in muscle strength that occurs with advancing age have been named Sarcopenia. Sarcopenic Obesity (SO) is the significant reduction in FFM combined with the excessive increase in body fat. The association between sarcopenia, muscle strength and SO with markers of inflammation has been poorly investigated in elderly Brazilian. Thus, the aim of this study was to investigate the association between sarcopenia, muscle strength and SO with inflammatory markers in Brazilian elderly women. Methodology: This is a study with a cross-sectional and correlational design. The sample consisted of 130 elderly women aged between 60 and 80 years from the community of Brasília, Federal District, Brazil. Participants were submitted to the following: body mass and body height assessment; evaluation of waist circumference by anthropometric tape; analysis of body composition by dual energy X-ray absorptiometry; assessment of handgrip muscle strength (HG) through hydraulic dynamometer and the collection of blood samples for analysis of inflammatory markers. The sample was divided into groups taking into consideration approaches previously suggested in the literature for sarcopenia and SO classification. The Mann-Whitney U test and T test were used to compare variables between groups, while the Spearman correlation test was used for correlation analysis. The analysis was conducted using the SPSS software version 18.0 adopting p≤0.05. Results: There was no difference between sarcopenic individuals compared to non-sarcopenic regarding HG, IL-6 and TNFα. CRP was significantly lower in sarcopenic group. Higher values of IL-6 were found in sarcopenic obese volunteers. A positive correlation was observed between CRP and body mass index, FM, waist circumference and waist circumference/HG index. IL-6 positively correlated with age, FM, waist circumference and the waist circumference/HG index. Handgrip strength was negatively associated with age and presented a trend of negative association with IL-6 (p=0.08). The subjects with serum IL-6 levels above 1.72pg/ml presented higher age, waist circumference, waist circumference/HG index and CRP compared to volunteers with concentrations below 1.72pg/ml. Also, handgrip strength was lower among subjects with higher IL-6 levels. Conclusions: It is possible to conclude that CRP and IL-6 are related to phenotypes that characterize SO in the population studied, that is, low FFM, low handgrip strength and high FM. Further studies should be undertaken in order to standardize the classifications of sarcopenia and SO and identify interventions that minimize the impact of changes in body composition related to aging in the aspect of inflammation.