The long-term effects of bariatric surgery for type 2 diabetes: systematic review and meta-analysis of randomized and non-randomized evidence

Medication and nutritional supplement use before and after bariatric surgery

CONTEXT AND OBJECTIVE:

Bariatric surgery has been an effective alternative treatment for morbid obesity and has resulted in decreased mortality, better control over comorbidities and reduced use of drugs. The objective of this study was to analyze the impact of bariatric surgery on medication drug and nutritional supplement use.

DESIGN AND SETTING:

Longitudinal study of before-and-after type, on 69 morbidly obese patients in a public hospital in Porto Alegre.

METHODS:

Through interviews, the presence of comorbidities and use of drugs with and without prescription were evaluated.

RESULTS:

Among the 69 patients interviewed, 85.5% had comorbidities in the preoperative period, with an average of 2.3 (± 1.5) per patient. The main comorbidities reported were hypertension, diabetes and dyslipidemia. 84.1% of the patients were using prescribed drugs in the preoperative period. The mean drug use per patient was 4.8, which decreased to 4.4 after the procedure. The surgery enabled significant reduction in use of most antidiabetic (84%), antilipemic (77%) and antihypertensive drugs (49.5%). On the other hand, there was a significant increase in use of multivitamins and drugs for disorders of the gastrointestinal tract. The dosages of most of the drugs that continued to be prescribed after surgery were decreased, but not significantly.

CONCLUSION:

After bariatric surgery, there were increases in the use of vitamins, gastric antisecretory drugs and antianemic drugs. Nevertheless, there was an overall reduction in drug use during this period, caused by suspension of drugs or dose reduction.

Ranking factors involved in diabetes remission after bariatric surgery using machine-learning integrating clinical and genomic biomarkers

As weight-loss surgery is an effective treatment for the glycaemic control of type 2 diabetes in obese patients, yet not all patients benefit, it is valuable to find predictive factors for this diabetic remission. This will help elucidating possible mechanistic insights and form the basis for prioritising obese patients with dysregulated diabetes for surgery where diabetes remission is of interest. In this study, we combine both clinical and genomic factors using heuristic methods, informed by prior biological knowledge in order to rank factors that would have a role in predicting diabetes remission, and indeed in identifying patients who may have low likelihood in responding to bariatric surgery for improved glycaemic control. Genetic variants from the Illumina CardioMetaboChip were prioritised through single-association tests and then seeded a larger selection from protein-protein interaction networks. Artificial neural networks allowing nonlinear correlations were trained to discriminate patients with and without surgery-induced diabetes remission, and the importance of each clinical and genetic parameter was evaluated. The approach highlighted insulin treatment, baseline HbA1c levels, use of insulin-sensitising agents and baseline serum insulin levels, as the most informative variables with a decent internal validation performance (74% accuracy, area under the curve (AUC) 0.81). Adding information for the eight top-ranked single nucleotide polymorphisms (SNPs) significantly boosted classification performance to 84% accuracy (AUC 0.92). The eight SNPs mapped to eight genes - ABCA1, ARHGEF12, CTNNBL1, GLI3, PROK2, RYBP, SMUG1 and STXBP5 - three of which are known to have a role in insulin secretion, insulin sensitivity or obesity, but have not been indicated for diabetes remission after bariatric surgery before.

No effect of different bariatric surgery procedures on LINE-1 DNA methylation in diabetic and nondiabetic morbidly obese patients

BACKGROUND

Bariatric surgery (BS) is proposed as a highly effective therapy for reducing weight and improving obesity-related co-morbidities. The molecular mechanisms involved in the metabolic improvement after BS are not completely resolved. Epigenetic modifications could have an important role.

OBJECTIVE

The aim of this study was to evaluate the effect of different BS procedures (Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy) on global DNA methylation (long interspersed nucleotide element 1 [LINE-1]) in a group of nondiabetic and diabetic severely obese patients.

SETTING

University hospital, Spain.

METHODS

This study included 60 patients (30 nondiabetic and 30 diabetic severely obese patients) undergoing BS: 31 patients underwent Roux-en-Y gastric bypass and 29 underwent laparoscopic sleeve gastrectomy. Before and 6 months post-BS, anthropometric data, blood pressure, and metabolic parameters were determined. LINE-1 DNA methylation was quantified by pyrosequencing. We used the methylation levels of tumor necrosis factor-α as a control gene promoter.

RESULTS

There were no differences between LINE-1 methylation levels at baseline and at 6 months after surgery (66.3±1.6 versus 66.2±2.06). Likewise, there was no statistically significant difference on LINE-1 methylation levels when we stratified according to metabolic status (diabetic versus nondiabetic), nor was there regarding the BS procedure. A strong correlation was shown between LINE-1 methylation levels and weight at baseline both in diabetic and nondiabetic obese patients (r = .486; P<.001). Tumor necrosis factor-α methylation levels increased significantly after BS in the group of diabetic obese patients.

CONCLUSION

After BS, global LINE-1 methylation is not modified in the short term. More studies are required to determine if LINE-1 is a stable epigenetic marker, or, on the contrary, if it is susceptible to modification by external factors such as changes in lifestyle or a surgical intervention.

Systematic review of risk prediction models for diabetes after bariatric surgery

BACKGROUND

Diabetes remission is an important outcome after bariatric surgery. The purpose of this study was to identify risk prediction models of diabetes remission after bariatric surgery.

METHODS

A systematic literature review was performed in MEDLINE, MEDLINE-In-Process, Embase and the Cochrane Central Register of Controlled Trials databases in April 2015. All English-language full-text published derivation and validation studies for risk prediction models on diabetic outcomes after bariatric surgery were included. Data extraction included population, outcomes, variables, intervention, model discrimination and calibration.

RESULTS

Of 2330 studies retrieved, eight met the inclusion criteria. Of these, six presented development of risk prediction models and two reported validation of existing models. All included models were developed to predict diabetes remission. Internal validation using tenfold validation was reported for one model. Two models (ABCD score and DiaRem score) had external validation using independent patient cohorts with diabetes remission assessed at 12 and 14 months respectively. Of the 11 cohorts included in the eight studies, calibration was not reported in any cohort, and discrimination was reported in two.

CONCLUSION

A variety of models are available for predicting risk of diabetes following bariatric surgery, but only two have undergone external validation.

Is Transforming Stem Cells to Pancreatic Beta Cells Still the Holy Grail for Type 2 Diabetes?

Diabetes is a progressive disease affecting millions of people worldwide. There are several medications and treatment options to improve the life quality of people with diabetes. One of the strategies for the treatment of diabetes could be the use of human pluripotent stem cells or induced pluripotent stem cells. The recent advances in differentiation of stem cells into insulin-secreting beta-like cells in vitro make the transplantation of the stem cell-derived beta-like cells an attractive approach for treatment of type 1 and type 2 diabetes. While stem cell-derived beta-like cells provide an unlimited cell source for beta cell replacement therapies, these cells can also be used as a platform for drug screening or modeling diseases.

Partial ileal bypass affords protection from onset of type 2 diabetes

BACKGROUND

Partial ileal bypass (PIB) in the National Institutes of Health-sponsored Program on the Surgical Control of the Hyperlipidemias (POSCH) randomized controlled trial was found to reduce plasma cholesterol, in particular low density lipoprotein cholesterol, with concomitant retardation of atherosclerotic cardiovascular disease and increased life expectancy. Glucagon-like peptide-1, related to amelioration of type 2 diabetes, is increased over 5-fold after PIB. We hypothesized that PIB, in addition to its action on cholesterol metabolism, may also prevent type 2 diabetes.

METHODS

We surveyed by telephone inquiry of former POSCH patients the 30+year posttrial incidence of type 2 diabetes or prediabetes, the presence of which was a trial exclusion criteria. We were able to contact 17.4% (n = 838) of the original POSCH population.

RESULTS

Of 66 control responders, 17 contracted type 2 diabetes (25.8%); of 80 PIB responders, 8 contracted type 2 diabetes (10%). The difference between groups was significant (P = .015 by Fisher exact test) with an odds ratio of .320 for the PIB group and an over 2-fold (2.6) increase in the incidence of type 2 diabetes in the controls. Including borderline type 2 diabetes (prediabetic) patients, these values were 22 of 66 controls (33.3%) and 10 of 80 PIB patients (12.5%), with an odds ratio of .286 and a P<.004, and again an over 2-fold (2.7) increase in the incidence of type 2 diabetes in the control patients.

CONCLUSION

PIB appears to afford partial protection from the onset of type 2 diabetes for over 30 years.

The use of adjustable gastric bands for management of severe and complex obesity

BACKGROUND

Obesity levels in the UK have reached a sustained high and ∼4% of the population would be candidates for bariatric surgery based upon current UK NICE guidelines, which has important implications for Clinical Commissioning Groups.

SOURCES OF DATA

Summary data from Cochrane systematic reviews, randomized controlled trials (RCTs) and cohort studies.

AREAS OF AGREEMENT

Currently, the only treatment that offers significant and durable weight loss for those with severe and complex obesity is surgery. Three operations account for 95% of all bariatric surgery in the UK, but the NHS offers surgery to only a small fraction of those who could benefit. Laparoscopic adjustable gastric banding (gastric banding) has potentially the lowest risk and up-front costs of the three procedures.

AREAS OF CONTROVERSY

Reliable Level 1 evidence of the relative effectiveness of the operations is lacking.

GROWING POINTS

As a point intervention, weight loss surgery together with the chronic disease management strategy for obesity can prevent significant future disease and mortality, and the NHS should embrace both.

AREAS TIMELY FOR DEVELOPING RESEARCH

Better RCT evidence is needed including clinical effectiveness and economic analysis to answer the important question 'which is the best of the three operations most frequently performed?' This review considers the current evidence for gastric banding for the treatment of severe and complex obesity.

Efficacy of Bariatric Surgery in Type 2 Diabetes Mellitus Remission: the Role of Mini Gastric Bypass/One Anastomosis Gastric Bypass and Sleeve Gastrectomy at 1 Year of Follow-up. A European survey

BACKGROUND

A retrospective study was undertaken to define the efficacy of both mini gastric bypass or one anastomosis gastric bypass (MGB/OAGB) and sleeve gastrectomy (SG) in type 2 diabetes mellitus (T2DM) remission in morbidly obese patients (pts).

METHODS

Eight European centers were involved in this survey. T2DM was preoperatively diagnosed in 313/3252 pts (9.62%). In 175/313 patients, 55.9% underwent MGB/OAGB, while in 138/313 patients, 44.1% received SG between January 2006 and December 2014.

RESULTS

Two hundred six out of 313 (63.7 %) pts reached 1 year of follow-up. The mean body mass index (BMI) for MGB/OAGB pts was 33.1 ± 6.6, and the mean BMI for SG pts was 35.9 ± 5.9 (p < 0.001). Eighty-two out of 96 (85.4%) MGB/OAGB pts vs. 67/110 (60.9%) SG pts are in remission (p < 0.001). No correlation was found in the % change vs. baseline values for hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) in relation to BMI reduction, for both MGB/OAGB or SG (ΔFPG 0.7 and ΔHbA1c 0.4 for MGB/OAGB; ΔFPG 0.7 and ΔHbA1c 0.1 for SG). At multivariate analysis, high baseline HbA1c [odds ratio (OR) = 0.623, 95% confidence interval (CI) 0.419-0.925, p = 0.01], preoperative consumption of insulin or oral antidiabetic agents (OR = 0.256, 95% CI 0.137-0.478, p = <0.001), and T2DM duration >10 years (OR = 0.752, 95% CI 0.512-0.976, p = 0.01) were negative predictors whereas MGB/OAGB resulted as a positive predictor (OR = 3.888, 95% CI 1.654-9.143, p = 0.002) of diabetes remission.

CONCLUSIONS

A significant BMI decrease and T2DM remission unrelated from weight loss were recorded for both procedures if compared to baseline values. At univariate and multivariate analyses, MGB/OAGB seems to outperform significantly SG. Four independent variables able to influence T2DM remission at 12 months have been identified.

Reconfiguration of the small intestine and diabetes remitting effects of Roux-en-Y gastric bypass surgery

PURPOSE OF REVIEW

Alterations in small intestinal physiology are proposed to play a causative role in the beneficial impact of Roux-en-Y gastric bypass on type 2 diabetes mellitus. The present article describes the key proposed mechanisms implicated with an emphasis on some of the newer findings in the field.

RECENT FINDINGS

Augmented incretin and diminished anti-incretin effects postsurgery are explored and a model proposed that reconciles the hindgut and foregut hypotheses of improved glycaemic control as being complementary rather than mutually exclusive. Synthesis of recent findings on postbypass changes in intestinal glucose handling then follows. Finally an updated view of the role of distal bile diversion and changes in the microbiota on enteroendocrine signalling is presented.

SUMMARY

A series of nonmutually exclusive changes in small intestinal physiology likely make a significant contribution to improved glycaemic control postgastric bypass. Longitudinal data indicate that these effects do not translate into a long-term cure. A number of surgery-induced changes, however, are amenable to device-based and pharmacology-based mimicry, and this is an area for prioritization of future research focus.

Is Bariatric Surgery an Effective Treatment for Type II Diabetic Kidney Disease?

Type II diabetic kidney disease is devastating to patients and society alike. This review will evaluate bariatric surgery as a treatment for diabetic kidney disease primarily through its ability to induce and maintain regression of type II diabetes. The review begins by outlining the global challenge of diabetic kidney disease, its link to obesity, and the comparative benefits of bariatric surgery on weight and type II diabetes. It then surveys comprehensively the relevant literature, which reports that although bariatric surgery is associated with reductions in albuminuria, its effect on harder clinical end points like progression of diabetic kidney disease is not known. The review also includes a critical assessment of the risks and costs of bariatric surgery and concludes by acknowledging the major knowledge gaps in the field and providing research strategies to overcome them. Until these knowledge gaps are filled, clinicians will be forced to rely on their own subjective judgment in determining the benefit-risk ratio of bariatric surgery for patients with diabetic kidney disease.

Long-Term Outcomes of Obesity Surgery and Implications for Health System Planning

Weight loss surgery is currently the only treatment that offers significant and sustained weight loss for those with severe and complex obesity. Obesity levels have reached a sustained high, whereby several percent of a country's population would qualify for surgery based upon current national guidelines. Worldwide, the provision of surgery is highly variable and to treat all the affected population, it would require at least a 100-fold increase in the provision of services. This has important cost and commissioning implications for health-care planners. Reliable level 1 evidence of the long-term effects of obesity surgery is still lacking, and the long-term complication profiles and re-operation rates unclear, which could have significant impact on health-care systems in the future. The chronic disease management of obesity in a population must be integrated with education and prevention and the brief intervention of weight loss surgery and the management of its sequelae, to prevent significant future morbidity and mortality.

Bariatric Surgery for Type 2 Diabetes Mellitus in Patients with BMI <30 kg/m2: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

The role of bariatric surgery in non-obese patients with type 2 diabetes (T2DM) remains unclear, and its use in clinical practice is controversial. We conducted a systemic review and meta-analysis to investigate the metabolic changes after surgical treatment in diabetic patients with body mass index (BMI) <30 kg/m2.

METHODS

We conducted a comprehensive search in MEDLINE (PubMed), EMBASE and the Cochrane Library of published articles from January 2000 to April 2013 reporting the clinical outcome changes in various metabolic outcomes in diabetic patients with BMI <30 kg/m2.

RESULTS

Ten prospective studies including 290 patients were included in the meta-analysis. Bariatric surgery led to an overall 2.79 kg/m2 [95%CI 2.05~3.53, P<0.00001] reduction in BMI, a 1.88%[95%CI 1.32~2.43, P<0.00001] reduction in glycosylated hemoglobin, a 3.70 mmol/L [95%CI, 1.93~5.47, P<0.00001] reduction in fasting blood glucose, a 6.69 mmol/L [95%CI, 2.29~11.08, P=0.003] reduction in postprandial glucose, anda 3.37 [95%CI 0.55~6.18, P=0.02] reduction in homeostasis model assessment of insulin resistance (HOMA-IR). After surgical treatment, 76.2% of the patients were insulin free, and 61.8% patients were off medication. In total, 90(42.4%), 10(37%) and 34(37.2%) patients had post-surgical HbA1c levels of <6%,<6.5% and<7%, respectively. No deaths were observed in the included studies, and the major complication rate was 6.2%.

CONCLUSIONS

Based on the currently available data, bariatric surgery might improve glycemic control and weight loss in a very limited range with a doubled surgical complication rate in drug-refractory T2DM patients with BMI <30 kg/m2. It remains too premature to suggest bariatric surgery for non-obese T2DM patients.

The impact of laparoscopic sleeve gastrectomy on weight loss and obesity-associated comorbidities: the results of 3 years of follow-up

BACKGROUND

Laparoscopic sleeve gastrectomy is one of the most recent advances in the surgical treatment of morbid obesity. Extended follow-up studies of large cohorts are needed to establish the usefulness of the operation. The objectives of this study are to delineate the role of sleeve gastrectomy in weight loss and in comorbidities among obese patients.

METHODS

Patients who underwent laparoscopic sleeve gastrectomy in a single bariatric center were followed up for a 3-year period. Weight loss and status of several comorbidities were assessed at the 1st, 3rd, 6th, 12th, 18th, 24(th), and 36th postoperative month.

RESULTS

Overall, after 3 years of follow-up of 88 patients, the mean body mass index (BMI) of the patients was 29.8 kg/m(2) (SD ±6.1), the % total weight loss was 38.1% (SD ±12.9), the % excess weight loss was 69.5% (SD ±17.5), and the % estimated BMI loss was 81.4% (SD ±22.3). These parameters changed significantly over the first year of follow-up (p < 0.001) and subsequently stabilized. The percentages of patients with hypertension (33.3%), hyperlipidemia (26.4%), diabetes mellitus (20.7%), obstructive sleep apnea (20.2%), and gastroesophageal reflux disease (GERD-27%) were significantly reduced (10.5, 9.2, 1.1, 1.1, and 9.2% respectively at 36 months postoperation), while 10 new cases of GERD appeared postoperatively. However, only three of the new GERD cases required medication, and only one of them experienced symptoms that persisted after the 3-year period.

CONCLUSION

Three years of close follow-up of patients who had undergone laparoscopic sleeve gastrectomy demonstrated satisfactory weight loss results. Promising results were also obtained regarding various comorbidities of obese patients. Longer follow-up studies for more patients are needed to delineate the exact role of sleeve gastrectomy on postoperative outcomes.

Is type 2 diabetes really resolved after laparoscopic sleeve gastrectomy? Glucose variability studied by continuous glucose monitoring

The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (<140 mg/dL) at 120 minutes OGTT. These interesting data could help clinicians to better individualize patients in which diabetes is not resolved and who could need more attention in order to prevent chronic complications of diabetes.

Metabolic changes induced by the biliopancreatic diversion in diet-induced obesity in male rats: the contributions of sleeve gastrectomy and duodenal switch

The mechanisms underlying the body weight and fat loss after the biliopancreatic diversion with duodenal switch (BPD/DS) remain to be fully delineated. The aim of this study was to examine the contributions of the two main components of BPD/DS, namely sleeve gastrectomy (SG) and duodenal switch (DS), on energy balance changes in rats rendered obese with a high-fat (HF) diet. Three different bariatric procedures (BPD/DS, SG, and DS) and three sham surgeries were performed in male Wistar rats. Sham-operated animals fed HF were either fed ad libitum (Sham HF) or pair weighed (Sham HF PW) by food restriction to the BPD/DS rats. A group of sham-operated rats was kept on standard chow and served as normal diet control (Sham Chow). All three bariatric surgeries resulted in a transient reduction in food intake. SG per se induced a delay in body weight gain. BPD/DS and DS led to a noticeable gut malabsorption and a reduction in body weight and fat gains along with significant elevations in plasma levels of glucagon-like peptide-1(7-36) and peptide YY. BPD/DS and DS elevated energy expenditure above that of Sham HF PW during the dark phase. However, they reduced the volume, oxidative metabolism, and expression of thermogenic genes in interscapular brown adipose tissue. Altogether the results of this study suggest that the DS component of the BPD/DS, which led to a reduction in digestible energy intake while sustaining energy expenditure, plays a key role in the improvement in the metabolic profile led by BPD/DS in rats fed a HF diet.