Temporal changes in plasma markers of oxidative stress following laparoscopic sleeve gastrectomy in subjects with impaired glucose regulation

Temporal Effects of Bariatric Surgery on Adipokines, Inflammation and Oxidative Stress in Subjects with Impaired Glucose Homeostasis at 4 Years of Follow-up

Background

Previous studies have examined changes in plasma markers of inflammation and oxidative stress up to 24 months following bariatric surgery, but there is limited evidence on the long-term effects of bariatric surgery.

Objectives

To examine the effects of bariatric surgery on adipokines (adiponectin, leptin), inflammatory cytokines [C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10(IL-10)] and global plasma measures of oxidative stress [thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAOS) 1 and 6 months, and 4 years post-surgery in subjects with obesity and impaired glucose regulation.

Methods

A prospective study comprising of 19 participants (13 females, mean age 50.4 ± 6.2 years, mean body mass index (BMI) 54 ± 14 kg/m², 17 type 2 diabetes) undergoing bariatric surgery (10 sleeve gastrectomy, 6 biliopancreatic diversion, 2 Roux-en-Y gastric bypass and 1 laparoscopic adjustable gastric banding). Serial measurements of the above markers were made pre-operatively, 1 and 6 months and 4 years post-operatively.

Results

Compared to pre-operative levels, significant decreases were seen 4 years post-operatively in CRP (11.4 vs 2.8 ng/mL, p < 0.001), IL-6 (8.0 vs 2.1 pg/mL, p < 0.001) and leptin (60.7 vs 32.1 pg/mL, p = 0.001). At 4 years, both fasting and 120 min TAOS significantly increased by 35% and 19% respectively. However, fasting and 120 min TBARS did not show any significant changes.

Conclusion

To our knowledge, no other studies have described changes in inflammation and oxidative stress at 4 years following bariatric surgery. This study contributes to the current literature supporting the longer-term beneficial effect of bariatric surgery on chronic inflammation and oxidative stress.

Roux-en-Y Gastric Bypass and Sleeve Gastrectomy Differently Affect Oxidative Damage Markers and their Correlations with Body Parameters

BACKGROUND

Bariatric surgery improves oxidative damage, but little is known about the differences between Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). This study compared changes in lipid and protein oxidative damage markers and their correlations with body parameters of patients before and after RYGB or SG.

METHODS

Body mass index (BMI), bioimpedance parameters, and biochemical parameters including lipid and protein oxidative damage markers were evaluated before and 6 months after surgery. Data were analyzed by t test or Mann-Whitney rank sum test and Spearman's correlation coefficient between oxidative damage and other parameters.

RESULTS

Twenty-five patients were submitted to RYGB and 14 to SG. There was a significant decrease of BMI, fat mass, fat-free mass, phase angle, serum total protein, transthyretin, and C-reactive protein in both groups (p < 0.05). Serum thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), and serum lipids (p < 0.05) were significantly decreased in the RYGB group. TBARS levels were significantly correlated with serum total cholesterol (r = 0.468), LDL (r = 0.439), BMI (r = 0.424), and fat mass (r = 0.40) (p < 0.05). In the SG group, AOPP levels were significantly correlated with serum C-reactive protein (baseline: r = 0.53, 6 months: r = 0.64) (p < 0.05). Alterations in these levels were negatively correlated with changes in BIA parameters [resistance (r = -0.574), reactance (r = -0.736), and phase angle (r = 0.549)] (p < 0.05).

CONCLUSIONS

RYGB seems to be better in attenuating oxidative damage after 6 months. The BMI reduction in the RYGB group suggests a concomitant decrease of lipid oxidative damage. In the SG group, changes in BIA parameters were inversely correlated with protein oxidative damage.

Acyl-ghrelin mediated lipid retention and inflammation in obesity-related Type 2 diabetes

Acyl-ghrelin has various peripheral effects including the potential role in mediating cellular lipid removal and macrophage polarization. Previous reports are contradictory as to how glycaemia and acyl-ghrelin mediates lipid retention and inflammation within individuals with Type 2 diabetes (T2D). Our aim was to explore acyl-ghrelin levels and ghrelin expression in relation to lipid and inflammatory markers within an ex vivo human model, biopsied visceral adipose tissue. Results indicated that acyl-ghrelin was associated with a decline in key lipid homeostasis genes ABCG1 and LXRβ expression. Within T2D there was also a down regulation of these genes which was independent of acyl-ghrelin levels. Circulatory pro-inflammatory markers (IL-6 and TNFα) had no association with ghrelin expression nor circulating acyl-ghrelin levels. Anti-inflammatory marker (IL-10) and total antioxidant status (TAOS%) were positively associated with ghrelin expression across samples from all groups combined (total sample cohort) and specifically within the obesity sample cohorts. Data supported the hypothesis that hyperglycaemia and acyl-ghrelin have a regulatory role in lipid retention. Furthermore, that both acyl- and desacyl-ghrelin is responsible for a protective inflammatory response; however this response is diminished in T2D.