Name: LEANDRA DE AGUIAR ALMEIDA
Type: MSc dissertation
Publication date: 28/08/2018
Advisor:
Name |
Role |
|---|---|
| FABIANO KENJI HARAGUCHI | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| FABIANO KENJI HARAGUCHI | Advisor * |
| HEBERTH DE PAULA | External Examiner * |
| VALDETE REGINA GUANDALINI | Internal Examiner * |
Summary: Introduction: Obesity is associated with a high morbidity and mortality rate. To reduce the risk of mortality and control the associated diseases, bariatric surgery is one of the treatments of choice. The first six months after surgery correspond to a period characterized by rapid weight loss and important changes in body composition and oxidative status may occur. Lipoperoxidation is an oxidative process that mainly affects the lipids of cellular membranes. And a measure can evaluate the integrity of these is the phase angle (PA), which reflects the variation of the passage of the electric current by the cellular membranes. Objectives: The objective of this study was to evaluate PA, parameters of oxidative damage and its correlations during the rapid phase of weight loss in subjects submitted to Roux-en-Y gastric bypass (RYGB). Methodology: The sample consisted of volunteers from the Bariatric and Metabolic Surgery Program of the University Hospital Cassiano Antônio de Moraes, in Vitória-ES, submitted to RYGB. Participants were evaluated in three moments: approximately one month before (M0), two months (M1) and six months (M2) after GRYDR. Anthropometric data were collected on body weight and height for the calculation of BMI. Body composition and PA were obtained through bioimpedance, blood samples were obtained for evaluation of the following parameters: serum albumin (ALB), triglycerides (TGL), malondialdehyde (MDA) and advanced protein oxidation products (AOPP). Statistical analysis of the data was performed using the software Statistical Package for the Social Sciences (SPSS), version 21.0. The Shapiro Wilk test was used to test data normality, analysis of variance for repeated measures (one-way ANOVA or Friedman test) and Pearson or Spearman correlations between FA and oxidative parameters. The level of significance was set at P<0.05. Results: There was a significant (P<0.05) reduction in body weight, BMI, PA, lean mass (LM) and fat mass (FM) throughout the time, with body weight, BMI, LM and FM values differing significantly between all moments and the PA in M1 and M2 differed from M0. Serum ALB concentrations did not change over time (P>0.05). Serum concentrations of TGL, MDA and AOPP were reduced over the periods (P<0.05). The concentrations of TGL differed between all moments, MDA in M2 differed from the other moments and AOPP in M2 differed from M0. When normalized by TGL concentrations, lipoperoxidation increased over time (P<0.05) with M1 and M2 different from M0, WHEREas when normalized by ALB concentrations, protein oxidation maintained the reduction over time (P<0.05), with significant difference between moments M2 and M0. In addition, a moderate negative correlation was observed between PA and MDA/TGL ratio and no significant correlation was detected between PA and AOPP/ALB ratio. Conclusion: In the fast phase of weight loss of patients submitted to GRDYR, there was a reduction of the PA and the oxidative damage parameters. However, there was an increase in proportional lipoperoxidation and a mean negative correlation between PA and MDA/TGL ratio, suggesting that PA can be used as a marker of lipoperoxidation during this period.
