Sustained Improvements in Glucose Metabolism Late After Roux-En-Y Gastric Bypass Surgery in Patients with and Without Preoperative Diabetes

The impact of prior obesity surgery on glucose metabolism after body contouring surgery: A pilot study

Body contouring surgery enhances physical appearance by means of surgical subcutaneous fat removal (SSFR). However, it remains unclear how SSFR may affect glucose metabolism and its broader effects on the endocrine system, especially in individuals who have undergone obesity (bariatric) surgery. This study aimed to evaluate the impact of SSFR on glucose excursion and insulin resistance in such patients, by examining them over three visits (within 1 week before surgery, 1 week after surgery, and 6 weeks after surgery). The independent impact of SSFR and history of obesity surgery on glucose homeostasis was evaluated in 29 participants, of whom ten patients (34%) had a history of obesity surgery. Indices of glucose metabolism were evaluated using cluster robust-error logistic regression. Results indicated that SSFR led to a gross improvement in insulin resistance at 6 weeks after the surgery in all patient's irrespective of BMI, type 2 diabetes mellitus (T2D) status, or history of obesity surgery (OR 0.22; p = 0.042). However, no effect was observed on glucose excursion except for a transient increase at visit 2 (1 week after surgery) in those without prior obesity surgery. Interestingly, participants with a history of obesity surgery had approximately half the odds being in the upper tertile for HOMA-IR (OR 0.44; p = 0.142) and ten-folds lower odds of having severely abnormal glucose excursion (OR 0.09; p = 0.031), irrespective of their BMI, T2D status, or time post SSFR. In conclusion, this study showed that body contouring surgery through SSFR resulted in (at least) short-term improvement in insulin resistance (independent of the participant's BMI, T2D status, or history of obesity surgery) without affecting glucose excursion under the GTT. On the contrary, obesity surgery may have a long-term effect on glucose excursion, possibly due to sustained improvement of pancreatic ß-cell function.

Sleeve Gastrectomy-Induced Weight Loss Increases Insulin Clearance in Obese Mice

Sleeve gastrectomy (SG) successfully recovers metabolic homeostasis in obese humans and rodents while also resulting in the normalization of insulin sensitivity and insulinemia. Reduced insulin levels have been attributed to lower insulin secretion and increased insulin clearance in individuals submitted to SG. Insulin degradation mainly occurs in the liver in a process controlled, at least in part, by the insulin-degrading enzyme (IDE). However, research has yet to explore whether liver IDE expression or activity is altered after SG surgery. In this study, C57BL/6 mice were fed a chow (CTL) or high-fat diet (HFD) for 10 weeks. Afterward, the HFD mice were randomly assigned to two groups: sham-surgical (HFD-SHAM) and SG-surgical (HFD-SG). Here, we confirmed that SG improves glucose-insulin homeostasis in obese mice. Additionally, SG reduced insulinemia by reducing insulin secretion, assessed by the analysis of plasmatic C-peptide content, and increasing insulin clearance, which was evaluated through the calculation of the plasmatic C-peptide:insulin ratio. Although no changes in hepatic IDE activity were observed, IDE expression was higher in the liver of HFD-SG compared with HFD-SHAM mice. These results indicate that SG may be helpful to counteract obesity-induced hyperinsulinemia by increasing insulin clearance, likely through enhanced liver IDE expression.

Appetite Changes in Weight Regain and Weight Maintenance After Roux-en-Y Gastric Bypass

PURPOSE

Roux-en-Y gastric bypass (RYGB) surgery produces significant weight loss. However, a number of patients experience weight regain years after surgery. Factors driving weight regain after surgical interventions are currently being explored. Our objective was to investigate appetite-related measures associated with weight regain after RYGB surgery.

MATERIALS AND METHODS

Using a cross-sectional design, 29 participants (49.6 ± 9.1 years of age; current BMI 32.4 ± 4.7 kg/m², 43.6 ± 8.9 months post-RYGB) were stratified into tertiles according to weight regain per month after nadir (weight maintenance (WM), n = 9; low weight regain (LWR), n = 10; and high weight regain (HWR), n = 10). The average weight regain was, by design, significantly different between the groups (WM = 2.2 ± 2.5 kg; LWR = 10.0 ± 3.4 kg; HWR = 14.9 ± 6.3 kg regained, p < 0.05). Appetite (visual analog scales), olfactory performance ("sniffin sticks"), eating behaviors (Three Factor Eating Questionnaire), food reward (Leeds Food Preference Questionnaire), and appetite-related hormones (ghrelin, PYY, GLP-1 and leptin) were measured fasting and in response to a standardized test meal.

RESULTS

Dietary restraint was significantly higher than clinical cutoffs in WM and LWR (p < 0.05). As expected, significant time effects were noted for ghrelin, PYY, and GLP-1, but there were no group differences.

CONCLUSION

The results suggest that appetite-related outcomes are similar across individuals who have maintained weight loss and experienced regain following RYGB.

Five-Year Outcomes of Sleeve Gastrectomy in Patients with Class I Obesity and Type 2 Diabetes Mellitus

BACKGROUND

Several studies have reported short and medium-term outcomes of laparoscopic sleeve gastrectomy (LSG) in patients with class I obesity and type 2 diabetes mellitus (T2DM). However, literature on outcomes beyond three years is scarce. The present study discusses the 5-year results of a previously reported cohort of 20 patients with class I obesity and T2DM, who had undergone LSG between March 2012 and March 2015.

MATERIALS AND METHODS

Patients were followed up in the bariatric clinic at yearly intervals as per institute protocol. Primary outcome was proportion of patients with a glycated haemoglobin (HbA1c) level of 6.5% or less, 5 years after LSG. Secondary outcomes were percentage total weight loss (%TWL), excess weight loss (EWL), weight regain and complications.

RESULTS

Out of 20 patients, 9 (45%) were male and 11 (55%) were female. Mean age was 41.6 ± 9.5 years. Mean pre-operative weight and BMI were 94.8 ± 14.4 kg and 33.4 ± 1.2 kg/m2, respectively. Median duration of diabetes was 42 months. Mean pre-operative fasting plasma glucose (FPG) and HbA1c were 171.1 ± 56.8 mg/dL and 8.7 ± 1.6%, respectively. Of the 17 patients available for follow-up at 5 years, 9 (52.9%) achieved HbA1c < 6.5% without medication, while 7 (41.2%) patients had improvement of their glycaemic status. One patient had recurrence of diabetes after initial remission. Mean %TWL and %EWL were 18% and 65.1%, respectively.

CONCLUSION

Laparoscopic sleeve gastrectomy is a reasonable option as a metabolic procedure for patients with T2DM and class I obesity.

GLP-1: 10-year follow-up after Roux-en-Y gastric bypass

PURPOSE

Glucagon-like peptide-1 (GLP-1) is a hormone widely studied in the short-term postoperative follow-up of Roux-en-Y gastric bypass due to its elevation and association with improvement of the glucose metabolism, but there are few studies in 10 years after RYGB follow-up with the same patient.

METHODS

Twenty morbidity obesity patients were submitted to RYGB; these patients were divided into two groups: normal glucose-tolerant morbidly obese patients (NGT) 11 patients and abnormal glucose metabolism morbidly obese patients (AGM) 9 patients. Oral glucose tolerance test (OGTT) was done during four different periods: T1 (first evaluation), T2 (pre-surgery), T3 (9 months after surgery) and T4 (10 years after surgery).

RESULTS

Groups were matched for age and gender, and as NGT and AGM had BMI of 46.31 ± 5.03 kg/m² and 50.87 ± 10.31 kg/m^2. After 10 years of RYGB, they were obesity grade I with BMI for NGT 32.45 ± 4.99 kg/m² and AGM 34.85 ± 4.46 kg/m². Plasma glucose levels decreased NGT group at T4 period had a significant reduction at 120 min after OGTT for NGT 55.49 ± 17.15 mg/dL (p˂0.001). Insulin levels changed from T1 to T4 for the NGT group. GLP-1 curves were statistically different between the NGT and AGM groups. The AGM group had a higher mean for GLP-1 secretion at T4 period and at 30 min of OGTT 63.85 ± 37.98 pmol/L when compared to NGT 50.73 ± 24.82 pmol/L with AGM > NGT with p˂0.001.

CONCLUSION

Evaluation of the same patient during 4 different periods shows that, even with weight regain, after 10-years of RYGB high levels of GLP-1 remained which can be associated with metabolic improvement especially at the NGT group.

Changing the dietary composition improves inflammation but not adipocyte thermogenesis in diet-induced obese mice

Pronounced weight loss was shown to improve adipocyte dysfunction and insulin sensitivity in obese subjects. While bariatric surgery is frequently accompanied by adverse side effects, weight loss due to caloric restriction is often followed by weight regain. Here we aimed to determine whether switching the diet from a metabolically harmful Western type diet to a balanced standard diet is sufficient to reverse adipocyte dysfunction in diet-induced obese mice. Male C57BL/6 mice were fed a Western diet for 10 weeks and afterwards switched to a standard diet for eight more weeks (WD/SD mice) or continued to be fed a Western diet (WD/WD mice) ad libitum. Mice fed SD for 18 weeks served as control group (SD/SD). Insulin sensitivity was similar in WD/SD and SD/SD mice despite increased body weight in WD/SD mice. Beiging markers Ucp-1, Cidea and Cox8b were drastically reduced in subcutaneous adipose tissue of WD/SD mice when compared with SD/SD mice. Also, in brown adipose tissue morphologic features and markers of thermogenesis were still altered in both WD/SD and WD/WD mice. However, adipocyte size, Hif1α and macrophage infiltration were significantly lower in both, brown and white adipose tissues of WD/SD compared to WD/WD mice and additionally, a shift toward anti-inflammatory M2 phenotype was found in WD/SD mice only. In conclusion our data suggest that switching the diet is sufficient to improve adipose tissue inflammation, while western diet negatively affects thermogenic capacity of brown adipose tissue, and inhibits beiging of white adipose tissue in the long-term.

Predictors of normalized HbA1c after gastric bypass surgery in subjects with abnormal glucose levels, a 2-year follow-up study

Clinical biomarkers can predict normalization of HbA1c after Roux-en-Y gastric bypass (RYGB) surgery, but it is unclear which are the most predictive.The aim of this study was to compare biomarkers for insulin sensitivity and other clinical parameters in the prediction of normalization of HbA1c after RYGB surgery. This study included 99 (23 men) obese subjects (BMI > 35 kg/m²) undergoing a laparoscopic RYGB. Clinical and biochemical examinations were performed pre-operatively and up to 2 years after surgery. Pre-operatively, normal fasting glucose levels were found in 25 individuals (NG), prediabetes in 46 and type 2 diabetes (T2DM) in 28. At baseline IGF-I (SD), IGFBP-1 and adiponectin levels were low while leptin was high. Weight loss was observed in all three groups, most in the prediabetes group. After 2 years HbA1c was decreased in prediabetes and T2DM. In all three groups insulin, HOMA-IR, lipids and blood pressure improved, IGFBP-1 and adiponectin increased and leptin decreased. IGF-I (SD) increased only in T2DM. In those with prediabetes or T2DM (n = 74), HbA1c at 2 years correlated to baseline BMI (r = -0.27, p = 0.028), age (r = 0.43, p < 0.001), HbA1c (r = 0.37, p = 0.001) and IGFBP-1 (r = 0.25, p = 0.038), and was normalized in 45/74 (61%) at 1 year and in 36 subjects (49%) at 2 years. These responders were younger, had higher BMI, larger waist circumference, lower HbA1c and lower IGFBP-1 levels at baseline. In a multiple regression model age (negative, p = 0.021) and waist circumference (positive, p = 0.047) were the only predictors for normalized HbA1c. RYGB normalized HbA1c in 49% at two years follow-up, which was predicted by low baseline IGFBP-1 level, a marker of hepatic insulin sensitivty and insulin secretion. However,. younger age and larger waist circumference were the only predictors of normalized HbA1c in multivariate analysis.