Inflammatory markers and bariatric surgery: a meta-analysis

The immune remodel: Weight loss-mediated inflammatory changes to obesity

Obesity is an escalating world problem that contributes to the complexity and cost of treatment of metabolic disorders. Obesity is the result of increased storage of energy in the form of adipose tissue, reducing the quality of daily life, and interfering with longevity. Obesity is also a chronic, low-grade inflammatory disorder. The inflammatory processes affect many organ systems with expanded numbers of immune cells and increased cytokine production. Long-term weight loss is difficult to achieve and maintain. Lifestyle modifications, pharmacologic treatments, and surgical methods are increasingly utilized to ameliorate excess body weight and the comorbidities of obesity, such as diabetes, cardiovascular disease, dyslipidemia, and cancers. Weight loss is also touted to reduce inflammation. Here we review the current literature on human obesity-related systemic and local changes to the immune system and circulating inflammatory mediators. Further, we consider the impact of weight loss to reduce the burden of inflammation, bearing in mind the different methods of weight loss—behavioral change vs. surgical intervention.

Impact of serum uric acid on renal function after bariatric surgery: a retrospective study

BACKGROUND

Despite a known negative association between serum uric acid level (SUA) and renal function, this correlation in patients after bariatric surgery remains unknown.

OBJECTIVE

To assess correlation between postoperative SUA and estimated glomerular filtration rate (eGFR) at 12 months after bariatric surgery.

SETTING

A single tertiary referral center.

METHODS

A total of 252 patients (age = 40.5 ± 11.2; body mass index = 39.0 ± 5.5 kg/m²) undergoing bariatric surgery divided into 2 groups (i.e., normal renal function [90 ≤ eGFR < 125 mL/min/1.73 m², n = 176] versus renal function impairment [eGFR < 90 mL/min/1.73 m², n = 76]) were assessed for relationships between SUA and eGFR in both groups (primary endpoint) and associations of percentage weight loss with changes in SUA (△SUA) and eGFR (△eGFR) for all patients (secondary endpoint) at 12 months.

RESULTS

Overall, prevalence of hyperuricemia was 40.4% and 22.2% (baseline and postoperative 12 mo, respectively). Reverse relationship was observed between SUA and eGFR (r = -.152, P = .007) for all patients with no association noted between baseline SUA and eGFR in each group as well as between SUA and eGFR at 12 months in the normal group (r = -.076, P = .437). The reverse relationship was found (r = -.417, P = .005) in renal function impairment group for whom SUA was identified as a predictor of eGFR at 12 months. There was no association of percentage weight loss with △SUA (r = .089, P = .601) and △eGFR (r = -.046, P = .785).

CONCLUSION

The results demonstrated a negative relationship between postoperative SUA and renal function in patients with preexisting renal dysfunction undergoing bariatric surgery. Clinical significance of our findings warrants further investigation.

Systemic Inflammation in Severe Obese Patients Undergoing Surgery for Obesity and Weight-Related Diseases

Background

Obesity is a worldwide disease related to genetic, environmental, and behavioral factors, and it is associated with high rates of morbidity and mortality. Recently, obesity has been characterized by a low-grade inflammatory state known as inflammome indicated by chronic increases in circulating concentrations of inflammatory markers. The purpose of this study was to evaluate the effect of weight loss induced by surgery for obesity and weight-related diseases on pro-inflammatory cytokine (TNF-α) and anti-inflammatory adipokine (adiponectin) levels, and on an adipose-derived hormone (leptin) in severely obese subjects.

Methods

This randomized, controlled trial involved 55 severe obese patients (50 women, age 18–63 years, and body mass index of 35.7–63 kg/m²) who underwent bariatric surgery (BS). Patients with a BMI > 65 kg/m² and clinical and mental instability, or significant and unrealistic expectations of surgery were excluded. Blood samples were collected during the fasting period to analyze tumor necrosis factor alpha (TNF-α), adiponectin, and leptin levels by enzyme-linked immunosorbent assay.

Results

At baseline, no significant difference was observed in the anthropometric, demographic, clinical characteristics and biochemistry and inflammatory markers between the control group (CG) and bariatric surgery group (BSG). The same finding was also observed when we compared the baseline variables to those at the 6-month follow-up in the CG. However, the same variables in the BSG group were significantly different between baseline and the 6-month follow-up after BS.

Conclusions

Weight loss induced by surgery for obesity and weight-related diseases reduced the inflammome state in severely obese patients.

The influence of bariatric surgery on oral drug bioavailability in patients with obesity: A systematic review

Anatomical changes in the gastrointestinal tract and subsequent weight loss may influence drug disposition and thus drug dosing following bariatric surgery. This review systematically examines the effects of bariatric surgery on drug pharmacokinetics, focusing especially on the mechanisms involved in restricting oral bioavailability. Studies with a longitudinal before-after design investigating the pharmacokinetics of at least one drug were reviewed. The need for dose adjustment following bariatric surgery was examined, as well as the potential for extrapolation to other drugs subjected to coinciding pharmacokinetic mechanisms. A total of 22 original articles and 32 different drugs were assessed. The majority of available data is based on Roux-en-Y gastric bypass (RYGBP) (18 of 22 studies), and hence, the overall interpretation is more or less limited to RYGBP. In the case of the majority of studied drugs, an increased absorption rate was observed early after RYGBP. The effect on systemic exposure allows for a low degree of extrapolation, including between drugs subjected to the same major metabolic and transporter pathways. On the basis of current understanding, predicting the pharmacokinetic change for a specific drug following RYGBP is challenging. Close monitoring of each individual drug is therefore recommended in the early postsurgical phase. Future studies should focus on the long-term effects of bariatric surgery on drug disposition, and they should also aim to disentangle the effects of the surgery itself and the subsequent weight loss.

Changes in Pain Sensitization After Bariatric Surgery

OBJECTIVE

To evaluate changes in pain (at the knee and elsewhere) and pain sensitization in obese subjects with knee pain who were having bariatric surgery compared with similarly obese individuals who were undergoing medical management.

METHODS

This study included a cohort of subjects who were having bariatric surgery and those undergoing medical management. Knee pain severity of the more painful knee (index knee) was assessed at baseline and at 12 months using the Western Ontario and McMaster Universities Osteoarthritis Index. The pressure pain threshold (PPT) was evaluated at the index patella and the right wrist. Low patella PPT may reflect peripheral and/or central sensitization, and low wrist PPT may reflect central sensitization. The mean change in measures of pain and pain sensitization was analyzed in the surgery and medical management groups separately.

RESULTS

A total of 45 subjects in the surgery group and 22 in the medical management group completed baseline and follow-up visits. The mean weight loss was 32.7 kg (29.0%) and 4.6 kg (4.1%) in the surgery and medical management groups, respectively. Knee pain decreased only in the surgery group, in which the PPT at the patella improved by 38.5% (P = 0.0007) and at the wrist by 30.9% (P = 0.005). There was no significant change in PPT in the medical management group.

CONCLUSION

Persons who underwent bariatric surgery experienced an improvement in pain sensitization, reflected by improvements in PPT. This improvement was observed not only at the patella, but also at the wrist, suggesting that central sensitization improved after bariatric surgery.

Bariatric surgery is independently associated with a decrease in the development of colorectal lesions

BACKGROUND

Obesity is a risk factor for colorectal cancer and possibly the formation of precancerous, colorectal polyps . Bariatric surgery is very effective for long-term weight loss; however, it is not known whether bariatric surgery decreases the risk of subsequent colonic neoplasia. We hypothesized that bariatric surgery would decrease the risk of developing colorectal lesions (new cancer and precancerous polyps).

METHODS

We reviewed all patients (n = 3,676) who underwent bariatric surgery (gastric bypass, sleeve gastrectomy, or gastric banding) at the University of Virginia (Charlottesville, VA) 1985-2015. Obese, nonoperative patients (n = 46,873) from an institutional data repository were included as controls. Cases and controls were propensity score matched 1:1 by demographics, comorbidities, body mass index, and socioeconomic factors. The matched cohort was compared by univariate analysis and conditional logistic regression.

RESULTS

A total of 4,462 patients (2,231 per group) with a median follow-up of 7.8 years were well-matched with no statistically significant baseline differences in initial body mass index (48 vs 49 kg/m²), sex, and age in addition to other comorbidities (all P > .05). The operative cohort had more weight loss (55.5% vs -1.4% decrease in excess body mass index, P < .0001). The operative cohort developed fewer colorectal lesions (2.4% vs 4.8%, P < .0001). We observed no differences in polyp characteristics or staging for patients who developed cancer (all P > .05). After risk adjustment, bariatric surgery was independently associated with a decrease in new colorectal lesions (OR 0.62, 95% CI 0.42-0.91, P = .016).

CONCLUSION

Bariatric surgery was associated with lesser, risk-adjusted incidence of new colorectal lesions in this large population of propensity matched patients undergoing bariatric surgery compared with a control group not undergoing bariatric surgery. These results suggest the benefits of bariatric surgery may extend beyond weight loss and mitigation of comorbidities.

Serum proteome changes and accelerated reduction of fat mass after laparoscopic gastric plication in morbidly obese patients

Laparoscopic Gastric Plication (LGP) is a relatively new bariatric surgical procedure which no part of the stomach is removed. It is not clearly understood how LGP leads to fatty tissue reduction. We aimed to investigate the impact of LGP on serum proteome and understand molecular mechanisms of LGP-induced weight loss post-surgery. A Prospective observational study of 16 obese individuals who underwent LGP was performed. A Label-free quantitative shotgun proteomics approach was used to compare serum proteome of subjects before surgery with serum of the same individuals 1 to 2 months post-surgery (T1) and 4 to 5 months post-surgery (T2). The proteome analysis revealed that 48 proteins were differentially regulated between pre-surgery and T1, and seven proteins between pre-surgery and T2 of which six proteins were shared between the two timepoints. Among differentially regulated proteins, four proteins (SRGN, FETUB, LCP1 and CFP) have not previously been described in the context of BMI/weight loss. Despite few differences following LGP, most regulated serum proteins are in accordance with alternative weight loss procedures. Pathway analysis revealed changes to lipid- and inflammatory pathways, including PPARα/RXRα, LXR/RXR and FXR/RXR activation, especially at T1. At T2, the pathways related to inflammation and immune system are most affected. SIGNIFICANCE: Among the available clinical therapies for morbid obesity, bariatric surgery is considered as the most effective approach to achieve long-term weight loss, alongside a significant improvement in metabolic syndrome. However, very little is known about the underlying mechanism associated with significant weight loss post-surgery. Understanding such mechanisms could lead to development of safer non-surgical weight loss approaches. We here present the first analysis of the impact of LGP on the serum proteome, to bring new insights into the underlying molecular mechanism. Our findings indicate that LGP has a comprehensive systemic effect based on the blood serum proteome profile which might account for accelerated reduction of fat mass after surgery, thus, food restriction is not the only reason for weight loss following this unique surgical approach. As secretory regions of the stomach are preserved in LGP and it is associated with minimal physiological and anatomical changes, the findings are of high importance in the field of bariatric surgery and weight loss.

The Role of Inflammation in Diabetes: Current Concepts and Future Perspectives

Diabetes is a complex metabolic disorder affecting the glucose status of the human body. Chronic hyperglycaemia related to diabetes is associated with end organ failure. The clinical relationship between diabetes and atherosclerotic cardiovascular disease is well established. This makes therapeutic approaches that simultaneously target diabetes and atherosclerotic disease an attractive area for research. The majority of people with diabetes fall into two broad pathogenetic categories, type 1 or type 2 diabetes. The role of obesity, adipose tissue, gut microbiota and pancreatic beta cell function in diabetes are under intensive scrutiny with several clinical trials to have been completed while more are in development. The emerging role of inflammation in both type 1 and type 2 diabetes (T1D and T1D) pathophysiology and associated metabolic disorders, has generated increasing interest in targeting inflammation to improve prevention and control of the disease. After an extensive review of the possible mechanisms that drive the metabolic pattern in T1D and T2D and the inflammatory pathways that are involved, it becomes ever clearer that future research should focus on a model of combined suppression for various inflammatory response pathways.

PYY plays a key role in the resolution of diabetes following bariatric surgery in humans

BACKGROUND

Bariatric surgery leads to early and long-lasting remission of type 2 diabetes (T2D). However, the mechanisms behind this phenomenon remain unclear. Among several factors, gut hormones are thought to be crucial mediators of this effect. Unlike GLP-1, the role of the hormone peptide tyrosine tyrosine (PYY) in bariatric surgery in humans has been limited to appetite regulation and its impact on pancreatic islet secretory function and glucose metabolism remains under-studied.

METHODS

Changes in PYY concentrations were examined in obese patients after bariatric surgery and compared to healthy controls. Human pancreatic islet function was tested upon treatment with sera from patients before and after the surgery, in presence or absence of PYY. Alterations in intra-islet PYY release and insulin secretion were analysed after stimulation with short chain fatty acids (SCFAs), bile acids and the cytokine IL-22.

FINDINGS

We demonstrate that PYY is a key effector of the early recovery of impaired glucose-mediated insulin and glucagon secretion in bariatric surgery. We establish that the short chain fatty acid propionate and bile acids, which are elevated after surgery, can trigger PYY release not only from enteroendocrine cells but also from human pancreatic islets. In addition, we identify IL-22 as a new factor which is modulated by bariatric surgery in humans and which directly regulates PYY expression and release.

INTERPRETATION

This study shows that some major metabolic benefits of bariatric surgery can be emulated ex vivo. Our findings are expected to have a direct impact on the development of new non-surgical therapy for T2D correction.

Serum biomarkers of inflammation and adiposity in the LABS cohort: associations with metabolic disease and surgical outcomes

BACKGROUND

The utility of serum biomarkers related to inflammation and adiposity as predictors of metabolic disease prevalence and outcomes after bariatric surgery are not well-defined.

METHODS

Associations between pre- and post-operative serum levels of four biomarkers (C-reactive protein (CRP), cystatin C (CC), leptin, and ghrelin) with baseline measures of adiposity and metabolic disease prevalence (asthma, diabetes, sleep apnea), and weight loss and metabolic disease remission after bariatric surgery were studied in the Longitudinal Assessment of Bariatric Surgery (LABS) cohort.

RESULTS

Baseline CRP levels were positively associated with the odds of asthma but not diabetes or sleep apnea; baseline CC levels were positively associated with asthma, diabetes, and sleep apnea; baseline leptin levels were positively associated with asthma and negatively associated with diabetes and sleep apnea; baseline ghrelin levels were negatively associated with diabetes and sleep apnea. Increased weight loss was associated with increased baseline levels of leptin and CRP and decreased baseline levels of CC. Remission of diabetes and asthma was not associated with baseline levels of any biomarker. A higher likelihood of asthma remission was associated with a greater decrease in leptin levels, and a higher likelihood of diabetes remission was predicted by a lesser decrease in CC. Bariatric surgery was associated with decreased post-operative CC, CRP, and leptin levels, and increased post-operative ghrelin levels.

CONCLUSION

This is the largest study to date of serum biomarkers of inflammation and adiposity in a bariatric surgery cohort. Biomarker levels correlate with metabolic disease prevalence prior to bariatric surgery, and with weight loss but not metabolic disease remission after surgery. Bariatric surgery regulates serum biomarker levels in a manner consistent with anti-inflammatory and compensatory orexigenic effects. These data contribute to our understanding of the mechanisms underlying the biologic effects of bariatric surgery.

Biomarkers of Colorectal Cancer Risk Decrease 6 months After Roux-en-Y Gastric Bypass Surgery

PURPOSE

The impact of weight loss on obesity-related colorectal cancer (CRC) risk is not well defined. Previous studies have suggested that Roux-en-Y gastric bypass (RYGB) surgery may have an unexpected adverse impact on CRC risk. This study aimed to investigate the impact of RYGB on biomarkers of CRC risk.

MATERIALS AND METHODS

Rectal mucosal biopsies and blood were obtained from patients undergoing RYGB (n = 22) and non-obese control participants (n = 20) at baseline and at a median of 6.5 months after surgery. Markers of systemic inflammation and glucose homeostasis were measured. Expression of pro-inflammatory genes and proto-oncogenes in the rectal mucosa was quantified using qPCR. Crypt cell proliferation state of the rectal mucosa was assessed by counting mitotic figures in whole micro-dissected crypts.

RESULTS

At 6.5 months post-surgery, participants had lost 29 kg body mass and showed improvements in markers of glucose homeostasis and in systemic inflammation. Expression of pro-inflammatory genes in the rectal mucosa did not increase and COX-1 expression fell significantly (P = 0.019). The mean number of mitoses per crypt decreased from 6.5 to 4.3 (P = 0.028) after RYGB.

CONCLUSION

RYGB in obese adults led to lower rectal crypt cell proliferation, reduced systemic and mucosal markers of inflammation and improvements in glucose regulation. These consistent findings of reduced markers of tumourigenic potential suggest that surgically induced weight loss may lower CRC risk.

Influence of weight loss on pulmonary function and levels of adipokines among asthmatic individuals with obesity: One-year follow-up

BACKGROUND

Individuals with obesity are more likely to develop asthma, but the exact mechanism is still uncertain and several hypotheses have been raised, such as the release of inflammatory mediators secreted by adipose tissue.

OBJECTIVE

To assess the effects of weight loss in patients submitted to bariatric surgery on pulmonary and systemic inflammation.

METHOD

The study evaluated patients undergoing bariatric surgery (Roux-en-Y gastric bypass) with the diagnosis of asthma, except smokers. The patients were evaluated at the time of entry into a preoperative weight loss group (T1), just before bariatric surgery (T2), six months after surgery (T3), and 12 months after surgery (T4). The following were measured: anthropometric data, dosage of systemic inflammatory markers by means of blood collection, pulmonary inflammatory markers obtained by induced sputum collection, pulmonary function parameters, and asthma activity assessed by a Asthma Control Test (ACT) questionnaire.

RESULTS

Nineteen patients participated in the study. There were significant reductions in the systemic levels of interleukin (IL)-8 (p = 0.002), C-reactive protein (CRP) (p = 0.003), leptin (p = 0.001) and tumor necrosis factor (TNF)-α (p = 0.007), and significant increase in the systemic levels of IL-6 (p = 0.004) over time and adiponectin in T2 (p = 0.025). In regards to pulmonary inflammation, there were significant reductions in the sputum levels of TNF-α (p < 0.001). There was no significant improvement of the pulmonary function parameters (p > 0.05) and significant improvement in asthma activity scores (p < 0.0001).

CONCLUSION

Weight loss was associated with significant changes in the systemic and pulmonary inflammatory profiles of individuals with asthma, leading to a better asthma control as a result of an increase in some anti-inflammatory mediators and a reduction of pro-inflammatory mediators.

Impact of bariatric surgery on cardiovascular and renal complications of diabetes: a focus on clinical outcomes and putative mechanisms

INTRODUCTION

Cardiovascular and renal disease accounts for a substantial proportion of the morbidity and mortality associated with obesity and type 2 diabetes mellitus (T2DM). Bariatric surgery is associated with improved long-term cardiovascular and renal outcomes.

AREAS COVERED

All major case-control, cohort, and randomized controlled trial studies of bariatric surgery in adults with T2DM were screened and data on prespecified cardiovascular and renal outcomes collated. Bariatric surgery reduces all-cause mortality and risk of cardiovascular disease, albuminuria and progressive chronic kidney disease. Patients with poorer glycemic control and established microvascular disease preoperatively may stand to benefit the most from the surgical approach. Reduced sympathetic drive, remission of glomerular hypertension, enhanced natriuresis, gut microbiota shifts, reduced systemic and renal inflammation, improved lipoprotein profiles, and reductions in chronic cardiac remodeling may all be implicated.

EXPERT COMMENTARY

Ongoing RCTs of bariatric surgery selectively recruiting patients with class 1 obesity and established microvascular complications of diabetes will help to better characterize which subgroups of patients benefit most from this effective therapy.

Chemerin, Inflammatory, and Nitrooxidative Stress Marker Changes Six Months after Sleeve Gastrectomy

Background

Chemerin is a chemokine known to be increased in morbidly obese (MO) patients and correlated with markers of inflammation and nitrooxidative stress. We aimed to evaluate the changes of serum chemerin six months after laparoscopic sleeve gastrectomy (SG) and to asses if these changes are accompanied by variations of inflammatory and nitrooxidative stress markers.

Material and Methods

We investigated the levels of chemerin, high-sensitive C-reactive protein (hsCRP), tumor necrosis factor alpha (TNF-α), nitrite and nitrate (NOx), total oxidant status (TOS), total antioxidant response (TAR), and oxidative stress index (OSI) in a group of 24 MO patients submitted to SG before and six months after surgery. The MO group was compared with 20 controls.

Results

hsCRP (p < 0.001), NOx (p < 0.001), TOS (p < 0.001), TAR (p = 0.007), and OSI (p = 0.001) were significantly different between the two groups. Six months after surgery, we noticed significant changes (42.28% decrease) of hsCRP (p = 0.044) and OSI (p = 0.041) (31.81% decrease), while no significant changes were observed for chemerin (p = 0.605), TNF-α (p = 0.287), NOx (p = 0.137), TOS (p = 0.158), and TAR (p = 0.563).

Conclusions

Our study showed no significant changes of chemerin, and except for hsCRP and OSI, no other inflammatory and nitrooxidative stress markers changed six months after surgery.

Effects of gastric bypass surgery followed by supervised physical training on inflammation and endothelial function: A randomized controlled trial

BACKGROUND AND AIMS

Obesity and physical inactivity are both associated with low-grade inflammation and endothelial dysfunction. Bariatric surgery improves markers of inflammation and endothelial function, but it is unknown if physical training after bariatric surgery can improve these markers even further. Therefore, we aimed to investigate the effects of Roux-en-Y gastric bypass (RYGB) followed by physical training on markers of low-grade inflammation and endothelial function.

METHODS

Sixty patients approved for RYGB underwent examinations pre-surgery, 6, 12, and 24 months post-surgery. Six months post-surgery, they were randomized 1:1 to an intervention group or a control group. The interventions consisted of two weekly sessions of supervised moderate intensity physical training for a period of 26 weeks. Fasting blood samples were analyzed for concentrations of interleukin 6 (IL-6), C-reactive protein (CRP), intercellular adhesion molecule 1 (ICAM-1), tissue-type plasminogen activator antigen (t-PA:Ag) and von Willebrand factor (vWF).

RESULTS

RYGB markedly improved markers of inflammation (IL-6, CRP) (p < 0.001) and endothelial function (ICAM-1, t-PA:Ag, vWF) (p < 0.05), and the improvements were sustained 24 months post-surgery (p < 0.01), except for the effects on vWF. We found no correlations between the changes in weight or BMI and the changes in markers of inflammation and endothelial function, except that the change in vWF was found to be inversely correlated with the changes in weight and BMI. We observed no effects of supervised physical training on markers on inflammation or endothelial function (p>0.1 for all).

CONCLUSIONS

RYGB causes substantial and sustained favorable effects on markers of inflammation and endothelial function. Supervised physical training after RYGB did not cause additional improvements.

Changes in Bile Acid Profile After Laparoscopic Sleeve Gastrectomy are Associated with Improvements in Metabolic Profile and Fatty Liver Disease

BACKGROUND

Bile acids (BA) modulate lipid and glucose metabolism in a feedback loop through production of fibroblast growth factor (FGF) 19 in the terminal ileum. Changes in BA after bariatric surgery may lead to improvements in the metabolic syndrome, including fatty liver disease. This study investigated the relationship between BA and metabolic and inflammatory profiles after laparoscopic sleeve gastrectomy (LSG).

METHODS

Patients undergoing LSG had fasting blood samples taken pre-operatively and 6 months post-surgery. Liver injury was measured using cytokeratin (CK) 18 fragments. BA were measured using liquid chromatography tandem-mass spectrometry. FGF-19 was measured using enzyme-linked immunosorbent assay.

RESULTS

The study included 18 patients (12 females), with mean age 46.3 years (SEM ± 2.9) and BMI 60.1 kg/m(2) (±2.6). After 6 months, patients lost 39.8 kg (±3.1; p < 0.001). Fourteen patients (78 %) had steatosis. FGF-19 increased from median 128.1 (IQR 89.4-210.1) to 177.1 (121.8-288.9, p = 0.045) at 6 months. Although total BA did not change, primary glycine- and taurine-conjugated BA, cholic acid decreased, and secondary BA, glycine-conjugated urodeoxycholic acid increased over the study period. These changes are associated with reduction in insulin resistance, pro-inflammatory cytokines and CK-18 levels.

CONCLUSIONS

The profile of individual BA is altered after LSG. These changes occur in the presence of reductions in inflammatory cytokines and markers of liver injury. This study supports evidence from recent animal models that LSG may have an effect on fatty liver through changes in BA metabolism.

Effect of Roux-en-Y Bariatric Surgery on Lipoproteins, Insulin Resistance, and Systemic and Vascular Inflammation in Obesity and Diabetes

Purpose

Obesity is a major modifiable risk factor for cardiovascular disease. Bariatric surgery is considered to be the most effective treatment option for weight reduction in obese patients with and without type 2 diabetes (T2DM).

Objective

To evaluate changes in lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction following Roux-en-Y bariatric surgery in obese patients with and without diabetes.

Materials and methods

Lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction were measured in 37 obese patients with (n = 17) and without (n = 20) T2DM, before and 6 and 12 months after Roux-en-Y bariatric surgery. Two way between subject ANOVA was carried out to study the interaction between independent variables (time since surgery and presence of diabetes) and all dependent variables.

Results

There was a significant effect of time since surgery on (large effect size) weight, body mass index (BMI), waist circumference, triglycerides (TG), small-dense LDL apolipoprotein B (sdLDL ApoB), HOMA-IR, CRP, MCP-1, ICAM-1, E-selectin, P-selectin, leptin, and adiponectin. BMI and waist circumference had the largest impact of time since surgery. The effect of time since surgery was noticed mostly in the first 6 months. Absence of diabetes led to a significantly greater reduction in total cholesterol, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol although the effect size was small to medium. There was a greater reduction in TG and HOMA-IR in patients with diabetes with a small effect size. No patients were lost to follow up.

Conclusion

Lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction improve mostly 6 months after bariatric surgery in obese patients with and without diabetes.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT02169518. https://clinicaltrials.gov/ct2/show/NCT02169518?term=paraoxonase&cntry1=EU%3AGB&rank=1.

Endocannabinoid receptor blockade increases vascular endothelial growth factor and inflammatory markers in obese women with polycystic ovary syndrome

CONTEXT

Animal studies suggest that cannabinoid receptor-1 (CB-1) blockade reduces inflammation and neovascularization by decreasing vascular endothelial growth factor (VEGF) levels associated with a reduction in inflammatory markers, thereby potentially reducing cardiovascular risk.

OBJECTIVE

To determine the impact of CB1 antagonism by rimonabant on VEGF and inflammatory markers in obese PCOS women.

DESIGN

Randomized, open-labelled parallel study.

SETTING

Endocrinology outpatient clinic in a referral centre.

SUBJECTS

Twenty patients with PCOS (PCOS) and biochemical hyperandrogenaemia with a body mass index of ≥30 kg/m² were recruited. Patients were randomized to 1·5 g daily of metformin or 20 mg daily of rimonabant.

MAIN OUTCOME MEASURES

Post hoc review to detect VEGF and pro-inflammatory cytokines TNF-α, IL-1β, IL-1ra, IL-2, IL6, IL-8, IL-10 and MCP-1 before and after 12 weeks of treatment.

RESULTS

After 12 weeks of rimonabant treatment, there was a significant increase in VEGF (99·2 ± 17·6 vs 116·2 ± 15·8 pg/ml, P < 0·01) and IL-8 (7·4 ± 11·0 vs 18·1 ± 13·2 pg/ml, P < 0·05) but not after metformin (VEGF P = 0·7; IL-8 P = 0·9). There was no significant difference in the pro-inflammatory cytokines TNF-α, IL-1β, IL-1ra, IL-2, IL6, IL-8, IL-10 and MCP-1 following either treatment.

CONCLUSION

This study suggests that rimonabant CB-I blockade paradoxically raised VEGF and the cytokine IL-8 in obese women with PCOS that may have offset the potential benefit associated with weight loss.

Therapeutic approaches targeting inflammation for diabetes and associated cardiovascular risk

Obesity-related sub-acute chronic inflammation has been associated with incident type 2 diabetes and atherosclerotic cardiovascular disease. Inflammation is increasingly considered to be a pathologic mediator of these commonly co-occurring diseases. A growing number of preclinical and clinical studies support the inflammatory hypothesis, but clinical trials to confirm the therapeutic potential to target inflammation to treat or prevent cardiometabolic conditions are still ongoing. There are multiple inflammatory signaling pathways. Regulation is complex, with substantial crosstalk across these multiple pathways. The activity of select pathways may be differentially regulated in different tissues. Pharmacologic approaches to diabetes management may have direct or indirect antiinflammatory effects, the latter potentially attributable to an improved metabolic state. Conversely, some antiinflammatory approaches may affect glucose metabolism and cardiovascular health. To date, clinical trials suggest that targeting one portion of the inflammatory cascade may differentially affect dysglycemia and atherothrombosis. Understanding the underlying biological processes may contribute to the development of safe and effective therapies, although a single approach may not be sufficient for optimal management of both metabolic and athrothrombotic disease states.

Role of Adiposity-Driven Inflammation in Depressive Morbidity

Depression and metabolic disorders, including overweight and obesity, appear tightly interrelated. The prevalence of these conditions is concurrently growing worldwide, and both depression and overweight/obesity represent substantial risk factors for multiple medical complications. Moreover, there is now multiple evidence for a bidirectional relationship between depression and increased adiposity, with overweight/obesity being associated with an increased prevalence of depression, and in turn, depression augmenting the risk of weight gain and obesity. Although the reasons for this intricate link between depression and increased adiposity remain unclear, converging clinical and preclinical evidence points to a critical role for inflammatory processes and related alterations of brain functions. In support of this notion, increased adiposity leads to a chronic low-grade activation of inflammatory processes, which have been shown elsewhere to have a potent role in the pathophysiology of depression. It is therefore highly possible that adiposity-driven inflammation contributes to the development of depressive disorders and their growing prevalence worldwide. This review will present recent evidence in support of this hypothesis and will discuss the underlying mechanisms and potential therapeutic targets. Altogether, findings presented here should help to better understand the mechanisms linking adiposity to depression and facilitate the identification of new preventive and/or therapeutic strategies.

The Impact of Obesity on Gallstone Disease, Acute Pancreatitis, and Pancreatic Cancer

Obesity is a well-recognized risk factor for gallstone formation and increases the risk for gallstone-related complications. Pancreatic diseases are impacted adversely by obesity. Although weight loss surgery increases the risk of gallstone disease, evidence suggests that bariatric surgery mitigates the obesity-associated adverse prognostication in acute pancreatitis. Obesity is also a significant risk factor for pancreatic cancer. Obesity is a global epidemic and is increasing worldwide and among all age groups. There is an urgent need for focused health policies aimed at reducing the incidence and prevalence of obesity. This article summarizes the current literature highlighting the association between obesity and the pathophysiology and outcome of gallstone disease, pancreatitis, and pancreatic cancer.

Longitudinal Changes in Serum Levels of Angiopoietin-Like Protein 6 and Selenoprotein P After Gastric Bypass Surgery

BACKGROUND

Bariatric surgery has beneficial effects on weight loss and metabolic profiles. Recent evidence suggests that liver-derived hepatokines play a role in the pathophysiology of metabolic diseases. However, few studies have reported longitudinal changes in hepatokines after gastric bypass surgery. We investigated changes in the serum levels of angiopoietin-like protein 6 (Angptl6) and selenoprotein P after gastric bypass surgery.

METHODS

We followed 10 patients who were treated with gastric bypass for weight loss. We measured metabolic parameters and the serum levels of Angptl6 and selenoprotein P before, 1 month after, and 9 months after surgery. We investigated the changes in those hepatokines after surgery and the associations between changes in Angptl6 and selenoprotein P, respectively, and metabolic parameters.

RESULTS

Body mass index decreased linearly. Levels of hemoglobin A1c (HbA1c), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), total cholesterol, triglyceride, LDL cholesterol, and Angptl6 were significantly lower 1 and 9 months after surgery. Fasting plasma glucose was normal throughout the study. Fasting insulin decreased 1 month after surgery but increased 9 months post-surgery. Levels of selenoprotein P increased linearly. Significant correlations were detected between the levels of Angptl6 and LDL cholesterol and fasting insulin. Changes in Angptl6 levels were significantly correlated with changes in total cholesterol and LDL cholesterol. Selenoprotein P levels were inversely correlated with GGT, and changes in selenoprotein P were inversely correlated with changes in homeostasis model assessment for insulin resistance (HOMA-IR).

CONCLUSIONS

Our results suggest that gastric bypass may alter the serum levels of hepatokines independent of weight loss, and these changes are related to certain hepatic metabolic changes.

Effects of Bariatric Surgery on Outcomes of Patients With Acute Pancreatitis

BACKGROUND & AIMS

The prevalence of obesity and number of patients undergoing bariatric surgery are increasing. Obesity has adverse effects in patients with acute pancreatitis (AP). We investigated whether bariatric surgery affects outcomes of patients with AP.

METHODS

We performed a retrospective study, collecting data from the US Nationwide Inpatient Sample (2007-2011) on all adult inpatients (≥18 years) with a principal diagnosis of AP (n = 1,342,681). We compared primary clinical outcomes (mortality, acute kidney injury, and respiratory failure) and secondary outcomes related to healthcare resources (hospital stay and charges) among patient groups using univariate and multivariate analyses. We performed a propensity score-matched analysis to compare outcomes of patients with versus without bariatric surgery.

RESULTS

Of patients admitted to the hospital with a principal diagnosis of AP, 14,332 (1.07%) had undergone bariatric surgery. The number of patients that underwent bariatric surgery doubled, from 1801 in 2007 to 3928 in 2011 (P < .001). AP in patients that had undergone bariatric surgery was most frequently associated with gallstones. Multivariate analysis associated prior bariatric surgery with decreased mortality (odds ratio, 0.41; 95% confidence interval, 0.18-0.92), shorter duration of hospitalization (0.65 days shorter; P < .001), and lower hospital charges ($3558 lower) than in patients with AP not receiving bariatric surgery (P < .001). A propensity score-matched cohort analysis found that mortality and odds of acute kidney injury were similar between patients with versus without history of bariatric surgery, whereas respiratory failure was less frequent in patients who received bariatric surgery (1.34% vs 4.42%; P < .001).

CONCLUSIONS

Prior bariatric surgery in patients hospitalized with AP is not adversely associated with in-hospital mortality, development of organ failure, or healthcare resource use. Bariatric surgery may mitigate the obesity-associated adverse prognostication in AP. These observations are pertinent for future research, because the prevalence of obesity and AP-related hospitalizations is increasing.

Differential methylation in inflammation and type 2 diabetes genes in siblings born before and after maternal bariatric surgery

OBJECTIVE

Siblings born before (BMS) and after (AMS) maternal biliopancreatic diversion (BPD) show differences in the methylome. The objective was to use a sibling-pair design to examine the effects from interpregnancy weight loss as a consequence of maternal bariatric surgery, other than BPD, on the methylome comparing BMS and AMS.

METHODS

Women with at least one child born before and one after bariatric surgery were identified in Swedish national registers. Whole blood samples from BMS (N = 31) and AMS (N = 31) siblings were collected for epigenetic methylation analysis while maternal information was collected from antenatal medical records.

RESULTS

In total 3,074 genes, with corresponding 23,449 CpG methylation sites, were differently methylated and associated with an overrepresentation of differently methylated CpG sites in genes involved with insulin receptor signaling, type 2 diabetes signaling, and leptin signaling in obesity, while the most significant differently methylated genes were HLA-DQA1, HLA-DQB1, and TSPAN18, when comparing BMS and AMS siblings.

CONCLUSIONS

These results suggest that maternal bariatric surgery, with subsequent weight loss between pregnancies, is associated with alterations in the methylome of genes involved in insulin receptor signaling, type 2 diabetes signaling, and leptin signaling in obesity in a comparison of BMS and AMS siblings.

The Pharmacokinetics of the CYP3A Substrate Midazolam in Morbidly Obese Patients Before and One Year After Bariatric Surgery

PURPOSE

Bariatric surgery is nowadays commonly applied as treatment for morbid obesity (BMI > 40 kg/m(2)). As information about the effects of this procedure on a drug's pharmacokinetics is limited, we aimed to evaluate the pharmacokinetics of CYP3A probe substrate midazolam after oral and intravenous administration in a cohort of morbidly obese patients that was studied before and 1 year post bariatric surgery.

METHODS

Twenty morbidly obese patients (aged 26-58 years) undergoing bariatric surgery participated in the study of which 18 patients returned 1 year after surgery. At both occasions, patients received 7.5 mg oral and 5 mg intravenous midazolam separated by 160 ± 48 min. Per patient and occasion, a mean of 22 blood samples were collected. Midazolam concentrations were analyzed using population pharmacokinetic modeling.

RESULTS

One year after bariatric surgery, systemic clearance of midazolam was higher [0.65 (7%) versus 0.39 (11%) L/min, mean ± RSE (P < 0.01), respectively] and mean oral transit time (MTT) was faster [23 (20%) versus 51 (15%) minutes (P < 0.01)], while oral bioavailability was unchanged (0.54 (9%)). Central and peripheral volumes of distribution were overall lower (P < 0.05).

CONCLUSIONS

In this cohort study in morbidly obese patients, systemic clearance was 1.7 times higher 1 year after bariatric surgery, which may potentially result from an increase in hepatic CYP3A activity per unit of liver weight. Although MTT was found to be faster, oral bioavailability remained unchanged, which considering the increased systemic clearance implies an increase in the fraction escaping intestinal first pass metabolism.

The Effect of Intraoperative N-Acetylcysteine on Hepatocellular Injury During Laparoscopic Bariatric Surgery. A Randomised Controlled Trial

BACKGROUND

The combination of pneumoperitoneum and intraoperative retraction of the left lobe of the liver leads to hepatocellular injury during laparoscopic gastric surgery. Fatty livers are more susceptible to ischaemic insults. This trial investigated whether the antioxidant N-acetylcysteine (NAC) reduced liver injury during laparoscopic sleeve gastrectomy (LSG).

METHODS

Patients undergoing LSG were randomised (single blinded) to receive intraoperative NAC infusion or standard anaesthetic treatment. Blood samples were taken before and after surgery (days 0 to 4). Primary endpoints included serum aminotransferases. Secondary measures were C-reactive protein, weight cell count (WCC), cytokines (interleukin 6 and 10) and cytokeratin-18 as markers of apoptosis. Intraoperative liver biopsy samples were assessed using a locally developed injury score.

RESULTS

Twenty patients (14 females, mean age 44.5 (SEM ± 2.9) years, mean BMI 60.8 (SEM ± 2.4) kg/m(2)) were recruited (NAC n = 10, control n = 10). The trial was stopped early after a planned interim analysis. Baseline liver function was similar. The peak rise in liver enzymes was on day 1, but levels were not significantly different between the groups. Rates of complications and length of stay were not significantly different. Secondary outcome measures, including white cell count (WCC), cytokines and cytokeratin (CK)-18 fragments, were not different between groups. Liver injury scores did not differ significantly.

CONCLUSIONS

NAC did not reduce intraoperative liver injury in this small number of patients. The heterogenous nature of the study population, with differences in co-morbidities, body mass index and intraabdominal anatomy, leads to a varied post-operative inflammatory response. Significant hepatocyte injury occurs through both necrosis and apoptosis.

Effects of bariatric surgery on markers of subclinical atherosclerosis and endothelial function: a meta-analysis of literature studies

BACKGROUND/OBJECTIVES

Several studies confirmed a significantly increased carotid intima-media thickness (IMT) and impaired flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) in obese subjects, but few data are available on the effects of bariatric surgery on these markers of cardiovascular (CV) risk. We performed a meta-analysis of studies evaluating changes in IMT, FMD and NMD in obese patients after bariatric surgery.

METHODS

A systematic search was performed in the PubMed, Web of Science, Scopus and EMBASE databases without any language or publication year restriction. The last search was performed in January 2015. In addition, the reference lists of all retrieved articles were manually reviewed. Prospective studies evaluating the impact of bariatric surgery on the markers of CV risk were included. Changes in IMT, FMD and NMD after bariatric surgery were expressed as mean differences (MD) with pertinent 95% confidence intervals (95% CIs). IMT has been expressed in millimeters (mm); FMD and NMD as percentage (%). Impact of clinical and demographic features on effect size was assessed by meta-regression.

RESULTS

Ten articles (314 obese patients) were included in the analysis. Six studies contained data on IMT (7 data sets; 206 patients), 8 studies on FMD (9 data sets; 269 patients) and 4 on NMD (4 data sets; 149 patients). After bariatric surgery, there was a significant reduction of IMT (MD: -0.17 mm; 95% CI: -0.290, -0.049; P=0.006) and a significant improvement in FMD (MD: 5.65%; 95% CI: 2.87, 8.03; P<0.001), whereas NMD did not change (MD: 2.173%; 95% CI: -0.796, 5.142; P=0.151). Interestingly, percentage of changes in the body mass index were associated with changes in IMT (Z=11.52, P<0.001), FMD (Z=-4.26, P<0.001) and NMD (Z=-3.81, P<0.001).

CONCLUSIONS

Despite heterogeneity among studies, bariatric surgery is associated with improvement of subclinical atherosclerosis and endothelial function. These effects may significantly contribute to the reduction of the CV risk after bariatric surgery.

Computed tomography-based assessment of abdominal adiposity changes and their impact on metabolic alterations following bariatric surgery

BACKGROUND

The aim of this study was to evaluate the effects of surgically induced weight loss on the abdominal adipose tissue depots and the metabolic profile in morbidly obese (MO) patients.

METHODS

The study was performed with a semi-automated quantification of adipose tissue compartments on single-slice abdominal CT series before surgery, 6 and 12 months after bariatric surgery. Thirty-eight MO patients with mean age of 35.7 ± 10.1 years and mean body mass index (BMI) of 43.6 ± 6.5 kg/m(2) were studied (20 patients underwent gastric banding and 18 patients underwent sleeve gastrectomy). Anthropometric measurements, metabolic and inflammatory parameters were analyzed in each patient.

RESULTS

Markedly decreased levels of total abdominal adipose tissue, abdominal subcutaneous adipose tissue (AbSAT) and visceral adipose tissue (VAT) at 6 and 12 months were noted in comparison to the preoperative values. The total % reduction of VAT was significant higher in comparison to the total % reduction of AbSAT at 12 months after bariatric surgery (P < 0.01) with the mean ratio of AbSAT/VAT to increase from 4.1 ± 1.7 preoperatively to 6.2 ± 3.1 at 12 months postoperatively (P < 0.001). In addition, high-sensitivity C-reactive protein (hsCRP) decreased significantly with weight loss after bariatric surgery and the total abdominal lipid loss was related to the decrease in hsCRP.

CONCLUSIONS

Significant changes in abdominal lipid deposition occurred in MO patients 6 and 12 months after bariatric surgery. The changes were significantly, correlated with the magnitude of BMI loss. The fat redistribution may contribute to the improvements in metabolic abnormalities.

Changes in inflammation, oxidative stress and adipokines following bariatric surgery among adolescents with severe obesity

BACKGROUND/OBJECTIVES

Inflammation, oxidative stress and dysregulation of adipokines are thought to be pathophysiological mechanisms linking obesity to the development of insulin resistance and atherosclerosis. In adults, bariatric surgery reduces inflammation and oxidative stress, and beneficially changes the levels of several adipokines, but little is known about the postsurgical changes among adolescents.

SUBJECTS/METHODS

In two separate longitudinal cohorts we evaluated change from baseline of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemo-attractant protein-1 (MCP-1), oxidized low-density lipoprotein cholesterol (oxLDL), adiponectin, leptin and resistin up to 12 months following elective laparoscopic Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG) surgery in adolescents with severe obesity.

RESULTS

In cohort 1, which consisted of 39 adolescents (mean age 16.5±1.6 years; 29 females) undergoing either RYGB or VSG, IL-6 (baseline: 2.3±3.4 pg ml(-1) vs 12 months: 0.8±0.6 pg ml(-1), P<0.01), leptin (baseline: 178±224 ng ml(-1) vs 12 months: 41.4±31.9 ng ml(-1), P<0.001) and oxLDL (baseline: 41.6±11.6 U l(-1) vs 12 months: 35.5±11.1 U l(-1), P=0.001) significantly decreased and adiponectin significantly increased (baseline: 5.4±2.4 μg ml(-1) vs 12 months: 13.5±8.9 μg ml(-1), P<0.001). In cohort 2, which consisted of 13 adolescents (mean age 16.5±1.6 years; 10 females) undergoing RYGB, results were similar: IL-6 (baseline: 1.7±0.9 pg ml(-1) vs 12 months: 0.4±0.9 pg ml(-1), P<0.05) and leptin (baseline: 92.9±31.3 ng ml(-1) vs 12 months: 37.3±33.4 ng ml(-1), P<0.001) significantly decreased and adiponectin significantly increased (baseline: 6.1±2.9 μg ml(-1) vs 12 months: 15.4±8.0 μg ml(-1), P<0.001). When the cohorts were combined to evaluate changes at 12 months, oxLDL also significantly decreased (baseline: 39.8±16.7 U l(-1) vs 12 months: 32.7±11.9 U l(-1), P=0.03).

CONCLUSIONS

Bariatric surgery produced robust improvements in markers of inflammation, oxidative stress and several adipokines among adolescents with severe obesity, suggesting potential reductions in risk for type 2 diabetes and cardiovascular disease.

Serum SPARC and matrix metalloproteinase-2 and metalloproteinase-9 concentrations after bariatric surgery in obese adults

BACKGROUND

Remodeling of the extracellular matrix (ECM) of adipose tissue is regarded as part of the pathophysiology of obesity. Secreted protein acidic and rich in cysteine (SPARC) was the first ECM protein described in adipose tissue. Matrix metalloproteinases (MMPs) also play a role in ECM remodeling, and MMP-2 and MMP-9 may be associated with abnormal ECM metabolism. Here, we investigated changes in serum SPARC, MMP-2, and MMP-9 concentrations after bariatric surgery in obese adults.

METHODS

We recruited 34 obese patients who were scheduled to undergo bariatric surgery for weight loss. We analyzed changes in serum SPARC, MMP-2, and MMP-9 concentrations before and 9 months after bariatric surgery and any associations between changes in SPARC, MMP-2, and MMP-9 concentrations and obesity-related parameters.

RESULTS

Serum leptin levels significantly decreased, and the serum adiponectin level significantly increased after bariatric surgery. The serum SPARC concentration decreased significantly from 165.0 ± 18.2 to 68.7 ± 6.7 ng/mL (p < 0.001), and the MMP-2 concentration also decreased significantly from 262.2 ± 15.2 to 235.9 ± 10.5 ng/mL (p < 0.001). Changes in the serum SPARC concentration were significantly correlated with HOMA-IR changes, and changes in the serum MMP-9 concentration were found to inversely correlate with serum adiponectin changes.

CONCLUSION

These findings show that significant decreases in serum SPARC and MMP-2 concentrations occur after bariatric surgery. Our results thus suggest that weight loss via bariatric surgery could alter the ECM environment, and that these changes are related to certain metabolic changes.

Role of neuroinflammation in the emotional and cognitive alterations displayed by animal models of obesity

Obesity is associated with a high prevalence of mood disorders and cognitive dysfunctions in addition to being a significant risk factor for important health complications such as cardiovascular diseases and type 2 diabetes. Identifying the pathophysiological mechanisms underlying these health issues is a major public health challenge. Based on recent findings, from studies conducted on animal models of obesity, it has been proposed that inflammatory processes may participate in both the peripheral and brain disorders associated with the obesity condition including the development of emotional and cognitive alterations. This is supported by the fact that obesity is characterized by peripheral low-grade inflammation, originating from increased adipose tissue mass and/or dysbiosis (changes in gut microbiota environment), both of which contribute to increased susceptibility to immune-mediated diseases. In this review, we provide converging evidence showing that obesity is associated with exacerbated neuroinflammation leading to dysfunction in vulnerable brain regions associated with mood regulation, learning, and memory such as the hippocampus. These findings give new insights to the pathophysiological mechanisms contributing to the development of brain disorders in the context of obesity and provide valuable data for introducing new therapeutic strategies for the treatment of neuropsychiatric complications often reported in obese patients.

Anti-inflammatory effects of gastric bypass surgery and their association with improvement in metabolic profile

Obesity is associated with chronic inflammation and metabolic disease. Bariatric surgery offers a treatment that can effectively reduce weight and improve the metabolic function. However, the effect of bariatric surgery on chronic inflammation in obesity is under-investigated. In this expert review, the authors outline the effect of Roux-en-Y gastric bypass, the most commonly performed bariatric surgery in current practice, on the markers of inflammation. They include a discussion of the relationship between inflammation and weight loss after surgery, the interaction between these markers and metabolic disease, and the effect on adipose tissue inflammation. They also briefly explore the role of glucagon-like-peptide 1 in remediating inflammation and the changes in gut microbiota after Roux-en-Y gastric bypass, and how they may be important in inflammation.

Immune aging, dysmetabolism, and inflammation in neurological diseases

As we age, the immune system undergoes a process of senescence accompanied by the increased production of proinflammatory cytokines, a chronic subclinical condition named as “inflammaging”. Emerging evidence from human and experimental models suggest that immune senescence also affects the central nervous system and promotes neuronal dysfunction, especially within susceptible neuronal populations. In this review we discuss the potential role of immune aging, inflammation and metabolic derangement in neurological diseases. The discovery of novel therapeutic strategies targeting age-linked inflammation may promote healthy brain aging and the treatment of neurodegenerative as well as neuropsychiatric disorders.

Effects of bariatric surgery on incidence of obesity-related cancers: a meta-analysis

Background

The aim of this meta-analysis was to investigate possible relationships between bariatric surgery and incidence of obesity-related cancers. Obesity is an established risk factor for obesity-related cancers but the effects of bariatric surgery on incidence of obesity-related cancers are uncertain.

Material/Methods

We searched 4 electronic databases to identify eligible studies: PubMed, Embase, Web of Science, and Google Scholar. Five observational studies were eligible and included in this meta-analysis. Random-effects or fixed-effects odds ratio (OR) and its corresponding 95% confidence interval (CI) were pooled.

Results

Meta-analysis of these 5 observational studies revealed that bariatric surgery was associated with a significantly (p=0.0004) reduced incidence of obesity-related cancers (OR=0.43, 95%CI, 0.27–0.69) when compared with control individuals. Pooled estimated data showed that bariatric surgery is associated with a 24% lower colorectal cancer (CRC) risk. No publication bias was detected by Egger’s or Begg’s tests.

Conclusions

Although bariatric surgery may significantly reduce incidence of obesity-related cancers, considering the limitations of these included studies, these findings should be confirmed by further well-designed studies.

Sclerostin levels and changes in bone metabolism after bariatric surgery

CONTEXT

The role of sclerostin as a key regulator of bone formation remains unknown after Roux-en-Y gastric bypass (RYGB) or laparoscopic sleeve gastrectomy (SG).

OBJECTIVES

The study objectives were evaluation of sclerostin and Dickkopf-1 (DKK-1) serum levels after surgery and correlations with bone turnover markers (P1NP, CTX), parathyroid hormone (iPTH) and areal bone mineral density (BMD), changes at total body, lumbar spine and total hip.

DESIGN AND SETTING

This was a prospective observational single-center two-arm study in premenopausal women with acute adipositas over 24 months.

PARTICIPANTS

Participants were 52 premenopausal women (40 ± 8 years, BMI 43.4) after RYGB and 38 premenopausal women (41 ± 7 years, BMI 45.7) after SG.

MAIN OUTCOME MEASURES

Prior to surgery and 1, 3, 6, 9, 12, 18, and 24 months after surgery sclerostin, DKK-1, CTX, P1NP levels and BMD were measured.

RESULTS

Sclerostin, CTX and (to a lesser extent) P1NP increased after surgery and remained elevated during the entire study period (P < 0.001). DKK-1 declined during months 3-9 (P < 0.005) and then remained unchanged, serum phosphate continuously increased (P < 0.001), iPTH remained within the upper normal limit. Sclerostin increases were significantly positively correlated with CTX and P1NP increases and negatively correlated with BMD loss. BMD independently declined regardless of RYGB and SG. Elevations of sclerostin, CTX, P1NP, and phosphate, but not DKK-1 and iPTH, were significant discriminating factors for BMD loss (AUC 0.920).

CONCLUSION

Rapid and sustained increases of sclerostin, CTX, and to a lesser extent, P1NP cause an increase in bone metabolism and result in BMD loss at all skeletal sites.