Selenium Nutritional Status and Glutathione Peroxidase Activity and Its Relationship with Hemodialysis Time in Individuals Living in a Brazilian Region with Selenium-Rich Soil.

Suboptimal selenium status may impair the antioxidant defense system in patients undergoing hemodialysis, compromising the selenoenzyme glutathione peroxidase activity. To evaluate the association between the duration of hemodialysis, nutritional selenium status, glutathione peroxidase activity (GPx), and thiobarbituric acid reactive substance (TBARS) levels in patients with chronic renal failure undergoing hemodialysis in a region of selenium-rich soils (Ceará, Northeast Brazil). The case-control study of 75 individuals aged 18 to 88 years was allocated between two groups: hemodialysis (n = 41) and control (n = 34). Plasma and erythrocytes selenium levels were determined by inductively coupled plasma optical emission spectrometry. The GPx activity and TBARS levels were also evaluated. In addition, the hemodialysis group was stratified according to the duration of treatment (≤ 59 months and ≥ 60 months). The Mann-Whitney test, Student's t test, and Pearson's or Spearman's correlation were applied according to the data distribution. Moreover, a quantile regression was performed. The significance level (p) was < 0.05. The hemodialysis group had lower selenium levels in their plasma and erythrocytes than the control group (p < 0.001). However, there was no difference in the GPx activity between the groups. Furthermore, an association between the hemodialysis group and selenium levels in plasma (coefficient - 16,343, p < 0.001) and erythrocytes (coefficient - 7839, p = 0.003) was observed by quantile regression, independent of age, sex, and body-mass index. In individuals who had undergone treatment for 60 months or more, GPx activity was lower (p = 0.026) and TBARS levels higher (p = 0.011) than in those who had undergone treatment for less than 60 months. The status of selenium was reduced in the hemodialysis group compared to the control group. The lower GPx activity and higher levels of TBARS in individuals who had undergone treatment for 60 months or more correlated with greater oxidative stress.

Relationship between selenium status and biomarkers of oxidative stress in Crohn's disease.

OBJECTIVE: Crohn disease (CD) is characterized by chronic intestinal inflammation and various factors involved in its pathogenesis including oxidative stress. The oxidative stress in CD may compromise antioxidant nutrients, such as selenium. The aim of this study was to assess the status of selenium and its relationship with markers of oxidative stress in patients with CD in comparison to controls. METHODS: The study included 47 patients with CD (20 with active disease and 27 in remission) and 25 healthy individuals. Blood samples were collected for the analysis of plasma and erythrocyte selenium concentrations using inductively coupled plasma optical emission spectrometry (ICP-OES). Selenoprotein P (SepP) was evaluated by sandwich enzyme-linked immunosorbent assay, erythrocyte glutathione peroxidase (GPx1) activity was assessed by using an automatic biochemistry analyzer, and the concentration of thiobarbituric acid reactive substances (TBARS) was measured. Comparative analyses were performed using one-way analysis of variance and Tukey's post hoc test. For correlations, Pearson's coefficient test was used. The determinants for CD and lipid peroxidation were indicated by odds ratio. RESULTS: Plasma and erythrocyte selenium levels and SepP concentrations were lower in the CD patient groups than in the healthy group. GPx1 activity and the concentration of TBARS were significantly higher in the CD groups. In the univariate analysis, plasma and erythrocyte selenium and TBARS were associated with CD. CONCLUSION: Patients with CD have impaired selenium status, which is related to the increased oxidative stress observed in these patients.

Breast cancer survivors have less lean mass and lower phase angle after cancer treatment / Sobreviventes do câncer de mama tem menos massa magra e menor ângulo de fase após o tratamento oncológico

Objective: To evaluate the weight status and body composition of women who survived breast cancer after cancer treatment. Methods: This is a before and after clinical study, in which 27 breast cancer survivors were evaluated before (T0) and after (T1) cancer treatment (surgical and clinical). Current weight and height were measured to determine the body mass index (BMI). Body composition was assessed by tetrapolar bioelectrical impedance. The percentage of fat and lean mass and the phase angle were calculated. We used Student's t-test to assess the difference among means of anthropometric variables and body composition between T0 and T1, and the McNemar's test to evaluate differences in the prevalence of overweight, adopting a 5% significance. Results: Patients have a mean increase of 2.6 kg in weight after treatment (p=0.00) and 1.15 km/m2 in BMI (p=0.00). The percentage of fat mass increased by 0.6% (p=0.003) in T1, while the lean mass decreased (p=0.03). Concerning the phase angle, the mean decrease is 0.6 (p=0.026) after treatment. Conclusion: Breast cancer survivors have increased adiposity, decreased lean mass, and compromised cell integrity after cancer treatment, suggesting elevated risk factors for disease recurrence.

Objetivo: Avaliar o estado do peso e a composição corporal de mulheres sobreviventes do câncer de mama após tratamento oncológico. Metodologia: Trata-se de estudo clínico do tipo antes e depois, em que 27 pacientes sobreviventes do câncer de mama foram avaliadas antes (T0) e depois (T1) do tratamento oncológico (cirúrgico e clínico). Aferiram-se peso atual e estatura para definição do índice de massa corporal (IMC). A avaliação da composição corporal deu-se por impedância bioelétrica tetrapolar, sendo aferidos percentual de massa gorda e de massa magra e ângulo de fase. Aplicou-se o teste t de Student para avaliar a diferença de médias das variáveis antropométricas e de composição corporal entre T0 e T1, bem como o teste de McNemar para avaliar diferenças na prevalência de sobrepeso, adotando significância de 5%. Resultados: As pacientes têm aumento médio de 2,6 kg após o tratamento (p=0,00) e 1,15 kg/m2 no IMC (p=0,00). O percentual de massa gorda aumenta 0,6% (p=0,003) e há redução na massa magra (p=0,03) no T1. Em relação ao ângulo de fase, há diminuição média de 0,6 (p=0,026) após o tratamento. Conclusão: Mulheres sobreviventes do câncer de mama têm aumento de adiposidade, redução da massa magra e piora da integridade celular após o tratamento oncológico, o que sugere acréscimo de fatores de risco para recidiva da doença.