Relação entre sarcopenia, inflamação e ângulo de fase de pacientes renais em tratamento hemodialítico

Abstract

Sarcopenia is a syndrome associated with several medical conditions, caused by the inflammatory and catabolic process common in chronic diseases, which occurs when muscle strength is detected, and its diagnosis is confirmed by the presence of reduced quantity or quality of the muscle. High inflammatory markers have been associated with reduced muscle mass and strength among hemodialysis patients. In addition, studies on the phase angle have shown that it shows nutritional status and is associated with anthropometric and body composition variables and correlates with muscle mass and strength. However, studies are still needed to elucidate the relationship between sarcopenia, inflammation and nutritional markers, such as the phase angle. To achieve the objectives of the thesis, two articles were prepared. The original article “Sarcopenia and inflammation in patients undergoing hemodialysis”, aimed to verify the relationship between sarcopenia and inflammation in patients undergoing hemodialysis. A cross-sectional study was carried out with 209 patients in five hemodialysis units in São Luís-MA who measured the ultra-sensitive reactive C-protein. Demographic, socioeconomic, anthropometric and clinical-laboratory data were collected. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People (grip strength <27kg for men and <16kg for women, muscle mass index per DEXA <7.0 kg / m² for men and <5.5 kg / m² for women). Inflammation was measured using ultra-sensitive reactive Protein-C (CRP-us> 0.3mg / dl). The results of this article showed that the patients had a mean age of 51.9 ± 15.0 years, with 59.3% being men, between 1 and 4 years of treatment (59.8%) and hypertensive (37.5%). Muscle mass was reduced in 41.3% of patients and muscle strength in 51.9%. The prevalence of sarcopenia was 29.2% and inflammation was 50.2%. Poisson regression analysis showed that sarcopenia was associated with increased CRP values (PR = 1.06; p = 0.005), age (PR = 1.02; p <0.001), BMI (PR = 0.74; p <0.001) and% body fat (PR = 1.07; p <0.001), in addition to males (PR = 5.7; p <0.001) and the presence of DM (PR = 1.87; p <0.001). The second article, entitled “Phase angle and sarcopenia in patients undergoing hemodialysis: a longitudinal study”, aimed to assess the influence of the phase angle on sarcopenia and its components in patients on hemodialysis. A case control study was conducted nested in the prospective cohort of patients with kidney disease undergoing hemodialysis. Cases were considered renal patients who, at the beginning of the cohort study, presented sarcopenia (n = 68) and for the control group, those who did not present sarcopenia (n = 141) were considered. In both groups, patients were followed for a period of one year. Sociodemographic data, morbidities, clinical, laboratory, nutritional status and sarcopenia were diagnosed according to the European Working Group on Sarcopenia (muscle mass assessed using DEXA and muscle function assessed by muscle grip strength), at the beginning and at the end of the study. The phase angle was obtained through bioimpedance at both times. Baseline and end-of-study characteristics of patients in each group were compared using the t-student test for paired samples or Wilcoxon and the association between sarcopenia at the beginning and end of the study was verified using the McNemar test, considering the significance level of 5%. The predictive role of the phase angle in sarcopenia was evaluated by the Longitudinal Mixed Effects Model, using the STATA 14.0 software. RESULTS: Sixty individuals were allocated to the case group (sarcopenic) and ninety to the control group (non-sarcopenic), with a predominance of males (80% and 57.8%, respectively) and mean age of 53.1 ± 16.1 years (case) and 46.9 ± 11.9 years (control); p = 0.009. The prevalence of sarcopenia at the beginning of the follow-up was 40%, higher among men (48% vs 24%; p <0.001) and increased to 48.7%, with 93.3% in the case group and 18.9% in the case group. control, this difference being significant (p = 0.004). Grip strength and lean mass decreased and there was an increase in% body fat, both among men in the case group and among men in the control group. Among women in the case group, an increase in body fat% was observed and among those in the control group, a significant decrease in lean mass was observed (37.5 ± 5.6 vs 36.5 ± 5.1; p = 0.001). As for the phase angle, a statistically significant decrease in PA was observed both among women (6.6 ± 0.9 ° vs 6.3 ± 1.2 °; p = 0.015) and among men in the control group (6.7 ± 0.9 vs 6, 2 ± 1.1; p = 0.002). A negative association was observed between phase angle and sarcopenia (β = -0.765; p = 0.031) and decreased lean mass (β = -0.712; p = 0.004). BMI was also negatively associated with sarcopenia (β = -0.764; p <0.001). Male gender (β = 5.340; p = 0.001), the presence of DM (β = 2.054; p = 0.047) and% body fat (β = 0.183; p = 0.005) were positively associated with sarcopenia. Regarding its components, the male gender (β = 4.177; p = 0.032), the presence of DM (β = 5.657; p = 0.016) and the BMI (β = 0.536; p = 0.066) were positively associated with the decrease in strength, muscle mass was negatively associated (β = -0.534; p = 0.002). Male gender (β = 6.142; p <0.001) and% body fat (β = 0.204; p <0.001) were positively associated with decreased muscle mass, whereas BMI (β = -0.849; p <0.001) was associated in a negative way. CONCLUSION: The results of this thesis showed that sarcopenia was highly prevalent among hemodialysis patients, being associated with inflammation, aging and phase angle. Body composition showed significant changes at the end of the study, as well as the phase angle. This was negatively associated with sarcopenia and muscle mass, demonstrating that it can be a predictor for sarcopenia. Thus, we suggest that this tool can be used to detect sarcopenia in this group and support its diagnosis, making it a useful indicator to be used in clinical practice, due to its low cost and easy use.