Immediate Metabolic Response Following Sleeve Gastrectomy in Obese Diabetics

Bariatric surgery and the neurohormonal switch: Early insulin resistance recordings after laparoscopic sleeve gastrectomy

Laparoscopic sleeve gastrectomy (LSG) is a bariatric operation with a safe risk profile. It has been proven to successfully reduce weight, decrease insulin resistance (IR), and ameliorate diabetes mellitus. The aim of this study was to determine if there is an early improvement in IR after LSG and its association with weight loss. This was a prospective observational study of 32 patients who underwent LSG at a single center over a 3-year period. Serum insulin and fasting glucose levels were recorded preoperatively, on day 1 postoperatively, and 3 weeks after LSG. IR levels were calculated using the Homeostasis Model Assessment 2 Version 2.23. IR levels were compared along with the overall weight loss, via body mass index. β-cell function was the secondary outcome. IR significantly improved the day after surgery with a statistically significant mean difference of 0.89 units (P = .043) and significantly more so 3 weeks postoperatively, with a mean difference of 4.32 units (P < .0005). β-cell function reduced 3 weeks postoperatively, with a mean difference of 23.95 %β (P = .025), while body mass index significantly reduced, with a mean difference of 4.32 kg/m2 (P < .0005). Early improvement of IR was observed on postoperative day 1 after LSG before any weight loss. This raises the possibility of an undetermined, underlying neurohormonal switch that improves IR. Further investigation is needed to determine this mechanism, as it may lead to an improvement in the medical management of diabetes mellitus.

Poor glycemic control in bariatric patients: a reason to delay or a reason to proceed?

BACKGROUND

More than 90% of patients with type 2 diabetes (T2D) have obesity, and over 85% of diabetic patients who undergo metabolic and bariatric surgery (MBS) will see improvement or resolution of diabetes. However, diabetes is a known risk factor for surgical complications.

OBJECTIVES

To determine whether poor preoperative glycemic control confers an increased perioperative risk after MBS.

SETTING

Academic Hospital.

METHODS

Retrospective review of data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). From the 2017-2018 MBSAQIP databases, we identified patients with diabetes who underwent Roux-en-Y gastric bypass or gastric sleeve surgery. Unmatched and propensity-matched univariate analyses, as well as multivariate logistic regressions, were performed to compare 30-day postoperative outcomes and complication rates between patients with poor (glycated hemoglobin [HbA1C] > 7.0) and good (HbA1C ≤ 7.0) glycemic control.

RESULTS

Of 40,132 T2D patients, 19,094 (52.42%) had an HbA1C level ≤ 7.0. Patients with poor glycemic control had slightly higher rates of overall morbidity (6.53% versus 5.49%, respectively; relative risk = 1.188; P < .001). However, in a 1:1 matched analysis of 23,930 patients controlling for body mass index, surgery type, approach, and co-morbidities, the findings of poorer outcomes were largely mitigated. In a multivariate analysis, poor glycemic control was not associated with morbidity.

CONCLUSIONS

In T2D patients, poor glycemic control does not independently increase the risk of 30-day morbidity following MBS. Adverse outcomes in the setting of poor glycemic control appear to be largely mediated by associated co-morbidities. Performing MBS in the setting of suboptimal glycemic control may be justified, with the understanding that delaying or refusing surgery can contribute to worsening of diabetes-related co-morbidities that, in turn, may ultimately have a more deleterious effect on outcomes.

Ultra-Early and Early Changes in Bile Acids and Insulin After Sleeve Gastrectomy Among Obese Patients

BACKGROUND AND OBJECTIVE

In obese patients, sleeve gastrectomy (SG) has shown mixed results on bile acid (BA) values. The aim of our study was to examine the potential ultra-early and early changes of the circulating total BA in relation with the changes of insulin resistance (IR) in obese patients submitted to laparoscopic SG. Materials and Methods: Twenty-four obese subjects were investigated for body mass index (BMI), total fasting BA, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and leptin before and at 7 and 30 d after SG. Results: After surgery, mean BMI decreased at the first (p < 0.001) and at the second time point (p < 0.001) relative to baseline. Total fasting BA values did not change significantly at 7 d (p = 0.938) and at 30 d (p = 0.289) after SG. No significant changes were found at 7 d (p = 0.194, p = 0.34) and 30 d (p = 0.329, p = 0.151) after surgery regarding fasting insulin and HOMA-IR, respectively. However, a trend of increased total fasting BA and decreased fasting insulin and HOMA- after laparoscopic SG has been found. Negative correlations between total fasting BA and insulin (r = -0.807, p = 0.009), HOMA-IR (r = -0.855, p = 0.014), and blood glucose (r = -0.761, p = 0.047), respectively, were observed at one month after SG. Conclusion: In conclusion, here, we found a lack of significant changes in total fasting BA, insulin, and HOMA-IR ultra-early and early after SG, which precluded us to consider a possible relation between the variations of BA and IR. However, the presence of the tendency for total fasting BA to increase and for insulin and HOMA-IR to decrease, as well as of the negative correlations one month after laparoscopic SG, suggest that this surgery brings about some changes that point towards the existence, and possibly towards the restoration, at least to some extent, of the link between BA and glucose metabolism.

Gastric mucosal devitalization reduces adiposity and improves lipid and glucose metabolism in obese rats

BACKGROUND AND AIMS

The gastric mucosa is an endocrine organ that regulates satiation pathways by expression of orexigenic and anorexigenic hormones. Vertical sleeve gastrectomy (VSG) excludes gastric mucosa and reduces gastric volume. Our study aimed to investigate the independent effects of altering gastric mucosa on obesity and its related comorbidities.

METHODS

Gastric mucosa devitalization (GMD) of 70% of the stomach was achieved by argon plasma coagulation in a high-fat diet rat model and was compared with VSG and sham surgery. In an 8-week follow-up study, we quantified body weight, visceral adiposity, insulin resistance index, cholesterol profiles, and free fatty acid profiles by enzyme-linked immunosorbent assay (ELISA). Following a 2-hour oral glucose tolerance test, the kinetics of ghrelin, glucagon-like peptide-1, peptide YY, and serum and liver bile acid levels were measured. Liver lipid content was quantified by ELISA.

RESULTS

GMD resulted in significant reductions in body weight, visceral and subcutaneous adipose tissue, and hepatic steatosis as well as an improvement in lipid metabolism. GMD resulted in significant reductions in food intake and intestinal malabsorption of free fatty acids, both contributing to improved body composition and metabolic profile. Mechanistically, GMD resulted in a significant reduction in serum palmitate levels as well as an increase in serum and liver bile acid levels, known to alter glucose and lipid metabolism. Similar changes were noted when VSG rats were compared with sham surgery rats.

CONCLUSIONS

Devitalization of gastric mucosa, independent of altering gastric volume, was able to reduce obesity-related comorbidities. The gastric mucosa may be a potential target for treating obesity and its associated comorbidities.

Changes in Blood microRNA Expression and Early Metabolic Responsiveness 21 Days Following Bariatric Surgery

Background: Early metabolic responses following bariatric surgery appear greater than expected given the initial weight loss and coincide with improvement in diabetes. We hypothesized that small non-coding microRNA changes might contribute to regulating mechanisms for metabolic changes and weight loss in patients with severe obesity and diabetes. Methods: Twenty-nine type 2 patients with severe obesity (mean BMI 46.2 kg/m²) and diabetes underwent Roux-en-Y gastric bypass (RYGB) surgery. Clinical measurements and fasting blood samples were taken preoperatively and at day 21 postoperatively. Normalization of fasting glucose and HbA1c following bariatric surgery (short-term diabetes remission) was defined as withdrawal of anti-diabetic medication and fasting glucose < 100 mg/dL (5.6 mmol/L) or HbA1c < 6.0%. MicroRNA expression was determined by quantitative polymerase chain reaction and tested for significant changes after surgery. Results: BMI decreased by 3.8 kg/m² 21 days postoperatively. Eighteen of 29 RYGB (62%) had short-term diabetes remission. Changes from pre- to post-surgery in 32 of 175 microRNAs were nominally significant (p < 0.05). Following multiple comparison adjustment, changes in seven microRNAs remained significant: miR-7-5p, let-7f-5p, miR-15b-5p, let-7i-5p, miR-320c, miR-205-5p, and miR-335-5p. Four pathways were over-represented by these seven microRNAs, including diabetes and insulin resistance pathways. Conclusion: Seven microRNAs showed significant changes 21 days after bariatric surgery. Functional pathways of the altered microRNAs were associated with diabetes-, pituitary-, and liver-related disease, with expression in natural killer cells, and pivotal intestinal pathology suggesting possible mechanistic roles in early diabetes responses following bariatric surgery.

Bariatric Surgery Prior to Index Screening Colonoscopy Is Associated With a Decreased Rate of Colorectal Adenomas in Obese Individuals

Objectives:

Obesity is an important risk factor for the development of colorectal cancer (CRC). Although the impact of bariatric surgery on CRC is conflicting, its impact on precursor lesions is unknown. The aim of this study was to determine whether bariatric surgery before index screening colonoscopy is associated with decreased development of colorectal adenomas.

Methods:

We performed a retrospective cohort study of bariatric surgery patients who had undergone index, screening colonoscopy at an academic center from 2001 to 2014. Patients who had bariatric surgery at least 1 year before index colonoscopy were compared with those who had surgery after colonoscopy, using multivariable logistic regression to control for presurgical body mass index, sex, gender, race, type of surgery, aspirin use, metformin use, smoking, and age at colonoscopy.

Results:

One hundred and twenty-five obese individuals who had bariatric surgery before colonoscopy were compared with 223 individuals who had colonoscopy after surgery. Adenomatous polyps were found in 16.8% of individuals who had surgery first vs. 35.5% who had colonoscopy before bariatric surgery (unadjusted odds ratio (OR) 0.37, 95% confidence interval (CI): 0.21–0.64, P=0.0003). After multivariable adjustment, bariatric surgery before index screening colonoscopy was associated with a decreased risk of adenomas at index colonoscopy (adjusted OR 0.37, 95% CI: 0.19–0.69, P=0.002).

Conclusions:

Bariatric surgery is associated with a decreased risk of colorectal adenomas in obese individuals without a family history of CRC.

Effects of sleeve gastrectomy on insulin resistance

BACKGROUND AND AIM

Obesity is a major risk factor for the onset of insulin resistance (IR), hyperinsulinemia and type 2 diabetes mellitus (T2DM) Evidence data has proven that beyond important weight loss bariatric surgery especially Roux-en-Y gastric bypass (RYGB) and bilio-pancreatic diversion (BPD) leads to significant early reduction of insulinemia and of IR calculated through the homeostatic model assessment (HOMA-IR), independently of fat mass decrease. Sleeve gastrectomy (SG) is now used as a sole weight loss operation with good results. Therefore, the aim of the present study was to investigate the early changes of fasting blood glucose, insulin and HOMA-IR in a group of morbidly obese (MO) patients i.e. at 7, 30 and 90 days after SG.

METHODS

The study included 20 MO patients (7 male and 13 female) submitted to SG. Anthropometrical (weight, body mass index -BMI, percent excess BMI loss -%EBMIL) and biochemical (plasma glucose, insulin and calculated HOMA-IR ) evaluation were performed before and at 7, 30 and 90 days after SG. In addition, a second group of 10 normal weight healthy subjects with a BMI ranging form 19 kg/m(2) to 23.14 kg/m(2), matched for age and gender was investigated.

RESULTS

Plasma glucose (p=0.018), insulin (p=0.004) and HOMA-IR (p=0.006) values were statistically different between the studied groups. After surgery, at every follow-up point, there were statistically different weight and BMI mean values relative to the operation day (p<0.003). BMI, decreased at 7 days (estimated reduction=2.79; 95% CI:[2.12;3.45]), at 30 days (estimated reduction=5.65; 95% CI:[3.57;7.73]) and at 90 days (estimated reduction=10.88; 95% CI:[7.35;14.41]) respectively after SG. We noted a tendency toward statistical significant change of mean insulin values at 7 days after surgery (corrected p=0.075), no statistical change at 30 days (corrected p=0.327) and a significant change at 90 days (corrected p=0.027) after SG as compared to baseline. There was a significant change in mean values of HOMA-IR at 30 days (corrected p=0.009) and at 90 days (corrected p=0.021) after the operation day.

CONCLUSIONS

The present study showed important early changes consisting in reductions of mean values of plasma insulin and HOMA-IR after SG.