Changes in risk factors and their contribution to reduction of mortality risk following gastric bypass surgery among obese individuals with type 2 diabetes: a nationwide, matched, observational cohort study

Gastric Bypass Mortality Trends in Racial Cohorts: Are We Improving?

INTRODUCTION

Roux-en-Y gastric bypass (RYGB) continues to be safely performed in racial cohorts. However, studies continue to report differences in complications, with non-Hispanic black (NHB) patients having a higher rate of adverse outcomes, including mortality. It is unclear how these disparate outcomes have evolved over time. Our objective was to determine RYGB procedure and mortality trends in racial cohorts.

METHODS

Using the 2015 to 2019 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Project (MBSAQIP) database, we identified primary RYGB cases performed laparoscopically or robotically. Non-Hispanic white (NHW) and non-Hispanic black (NHB) patient cohorts were matched based on patient and surgical characteristics. Conditional logistic regression analysis was conducted on the matched pairs. Primary outcomes of interest included year-to-year all-cause and procedure-related mortality. Stata/MP 16.1 was utilized for analysis, and a p-value of < 0.05 and a 95% confidence interval that excluded 1 were considered significant.

RESULTS

A total of 148,829 RYGB cases in NHW (82.8%) and Black (17.2%) patients were analyzed. RYGB trends remain similar for NHB and NHW patients over 5 years. In matched cohorts, all-cause mortality (OR 2.23; 95% CI: 1.16-4.29), aggregate related readmission (OR 1.39; 95% CI: 1.27-1.51), related reintervention (OR 1.36; 95% CI: 1.19-1.56), and VTE (OR 1.86; 95% CI: 1.40-2.45) were more likely in NHB patients. During the study period, year-to-year mortality was higher in NHB patients compared to NHW patients.

CONCLUSION

Over a 5-year period, year-to-year mortality remains higher in NHB patients after RYGB. While bariatric outcomes continue to improve, outcome gaps between racial cohorts seem to persist.

Potential Effects of Bariatric Surgery on the Incidence of Heart Failure and Atrial Fibrillation in Patients With Type 2 Diabetes Mellitus and Obesity and on Mortality in Patients With Preexisting Heart Failure: A Nationwide, Matched, Observational Cohort Study

Background

Obesity and diabetes mellitus are strongly associated with heart failure (HF) and atrial fibrillation (AF). The benefits of bariatric surgery on cardiovascular outcomes are known in people with or without diabetes mellitus. Surgical treatment of obesity might also reduce the incidence of HF and AF in individuals with obesity and type 2 diabetes mellitus (T2DM).

Methods and Results

In this register‐based nationwide cohort study we compared individuals with T2DM and obesity who underwent Roux‐en‐Y gastric bypass surgery with matched individuals not treated with surgery. The main outcome measures were hospitalization for HF and/or AF and mortality in patients with preexisting HF. We identified 5321 individuals with T2DM and obesity who had undergone Roux‐en‐Y gastric bypass surgery between January 2007 and December 2013 and 5321 matched controls. The individuals included were 18 to 65 years old and had a body mass index >27.5 kg/m². The follow‐up time for hospitalization was until the end of 2015 (mean 4.5 years) and the end of 2016 for death. Our results show a 73% lower risk for HF (hazard ratio [HR], 0.27; CI, 0.19–0.38), 41% for AF (HR, 0.59; CI, 0.44–0.78), and 77% for concomitant AF and HF (HR, 0.23; CI, 0.12–0.46) in the surgically treated group. In patients with preexisting HF we observed significantly lower mortality in the group who underwent surgery (HR, 0.23; 95% CI, 0.12–0.43).

Conclusions

Bariatric surgery may reduce risk for HF and AF in patients with T2DM and obesity, speculatively via positive cardiovascular and renal effects. Obesity treatment with surgery may also be a valuable alternative in selected patients with T2DM and HF.

Reduction of oxidative stress on DNA and RNA in obese patients after Roux-en-Y gastric bypass surgery-An observational cohort study of changes in urinary markers

Increased oxidative stress in obesity and diabetes is associated with morbidity and mortality risks. Levels of oxidative damage to DNA and RNA can be estimated through measurement of 8-oxo-7,8-dihydro-2´-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) in urine. Both markers have been associated with type 2 diabetes, where especially 8-oxoGuo is prognostic for mortality risk. We hypothesized that Roux-en-Y gastric bypass (RYGB) surgery that has considerable effects on bodyweight, hyperglycemia and mortality, might be working through mechanisms that reduce oxidative stress, thereby reducing levels of the urinary markers. We used liquid chromatography coupled with tandem mass spectrometry to analyze the content of 8-oxodG and 8-oxoGuo in urinary samples from 356 obese patients treated with the RYGB-procedure. Mean age (SD) was 44.2 (9.6) years, BMI was 42.1 (5.6) kg/m2. Ninety-six (27%) of the patients had type 2 diabetes. Excretion levels of each marker before and after surgery were compared as estimates of the total 24-hour excretion, using a model based on glomerular filtration rate (calculated from cystatin C, age, height and weight), plasma- and urinary creatinine. The excretion of 8-oxodG increased in the first months after RYGB. For 8-oxoGuo, a gradual decrease was seen. Two years after RYGB and a mean weight loss of 35 kg, decreased hyperglycemia and insulin resistance, excretion levels of both markers were reduced by approximately 12% (P < 0.001). For both markers, mean excretion levels were about 30% lower in the female subgroup (P < 0.0001). Also, in this subgroup, excretion of 8-oxodG was significantly lower in patients with than without diabetes. We conclude, that oxidative damage to nucleic acids, reflected in the excretion of 8-oxodG and 8-oxoGuo, had decreased significantly two years after RYGB-indicating that reduced oxidative stress could be contributing to the many long-term benefits of RYGB-surgery in obesity and type 2 diabetes.

Renal and Cardiovascular Outcomes After Weight Loss From Gastric Bypass Surgery in Type 2 Diabetes: Cardiorenal Risk Reductions Exceed Atherosclerotic Benefits

OBJECTIVE

We examined detailed renal and cardiovascular (CV) outcomes after gastric bypass (GBP) surgery in people with obesity and type 2 diabetes mellitus (T2DM), across several renal function categories, in a nationwide cohort study.

RESEARCH DESIGN AND METHODS

We linked data from the National Diabetes Register and the Scandinavian Obesity Surgery Register with four national databases holding information on socioeconomic variables, medications, hospitalizations, and causes of death and matched 5,321 individuals with T2DM who had undergone GBP with 5,321 who had not (age 18-65 years, mean BMI >40 kg/m², mean follow-up >4.5 years). The risks of postoperative outcomes were assessed with Cox regression models.

RESULTS

During the first years postsurgery, there were small reductions in creatinine and albuminuria and stable estimated glomerular filtration rate (eGFR) in the GBP group. The incidence rates of most outcomes relating to renal function, CV disease, and mortality were lower after GBP, being particularly marked for heart failure (hazard ratio [HR] 0.33 [95% CI 0.24, 0.46]) and CV mortality (HR 0.36 [(95% CI 0.22, 0.58]). The risk of a composite of severe renal disease or halved eGFR was 0.56 (95% CI 0.44, 0.71), whereas nonfatal CV risk was lowered less (HR 0.82 [95% CI 0.70, 0.97]) after GBP. Risks for key outcomes were generally lower after GBP in all eGFR strata, including in individuals with eGFR <30 mL/min/1.73 m².

CONCLUSIONS

Our data suggest robust benefits for renal outcomes, heart failure, and CV mortality after GBP in individuals with obesity and T2DM. These results suggest that marked weight loss yields important benefits, particularly on the cardiorenal axis (including slowing progression to end-stage renal disease), whatever the baseline renal function status.

Long-term outcomes of macrovascular diseases and metabolic indicators of bariatric surgery for severe obesity type 2 diabetes patients with a meta-analysis

There is currently no detailed evidence for the long-term effects of bariatric surgery on severely obese with type 2 diabetes, such as the risk of myocardial infarction and stroke. In order to provide evidence on the risks of macrovascular diseases and metabolic indicators of bariatric surgery follow-up for more than five years, we searched in the Cochrane library, Pubmed, and EMBASE databases from the earliest studies to January 31, 2019. Randomized clinical trials or cohort studies compared bariatric surgery and conventional medical therapy for long-term incidence of macrovascular events and metabolic outcomes in severely obese patients with T2DM. Fixed-effects and random-effects meta-analyses were performed to pool the relative risks (RRs), hazard ratios (HRs) and weighted mean difference (WMD). Publication bias and heterogeneity were examined. Four RCTs and six cohort studies were finally involved in this review. Patients in the bariatric surgery group as compared to the conventional treatment group had lower incidence of macrovascular complications (RR = 0.43, 95%CI = 0.27~0.70), cardiovascular events (CVEs) (HR = 0.52, 95%CI = 0.39~0.71), and myocardial infarction (MI) (RR = 0.40, 95%CI = 0.26~0.61). At the same time, the results demonstrate that bariatric surgery is associated with better weight and better glycemic control over the long-term than non-surgical therapies, and reveal that different surgical methods have different effects on various metabolic indicators. Bariatric surgery significantly decreases macrovascular complications over the long term and is associated with greater weight loss and better intermediate glucose outcomes among T2DM patients with severe obesity as compared to patients receiving only conservative medical measures.

Phosphatidylcholine and its relation to apolipoproteins A-1 and B changes after Roux-en-Y gastric bypass: a cohort study

Background

Phosphatidylcholine (PC), the most abundant of the phospholipids, has several metabolic functions in organs such as the liver and the intestine, important structural- and signaling functions in biological membranes, and might have a role in the effects of Roux-en-Y gastric bypass (RYGB), an operation known to ameliorate metabolic diseases, including type 2 diabetes. We hypothesized that serum PC, as a reflection of phospholipid metabolism, changes after RYGB, and that changes are related to weight loss and possibly to changes in glucose metabolism (reflected in the HbA1c-level) as well as to changes in serum Apo A1, Apo B and Apo B/Apo A1 ratio.

Methods

In a cohort of 220 RYGB patients, we studied changes in serum PC after RYGB in relation to serum Apo A1 and Apo B, the main apolipoproteins in HDL- and LDL/VLDL-particles, respectively, up to 2 years following RYGB-surgery.

Results

Serum PC reached its lowest levels 3 months postoperatively to later rebound to preoperative levels 24 months after RYGB. No difference was seen between patients with or without type 2 diabetes. Serum Apo A1 showed a similar pattern whereas serum Apo B concentrations stayed low after the initial decrease after RYGB. As a result, the Apo B / Apo A1 ratio constantly decreased during follow-up. There was a strong positive correlation between PC and Apo A1, and between PC and Apo B, but none between Apo A1 and Apo B. After RYGB surgery, both PC and Apo A1, but not Apo B, correlated positively to weight loss. In relation to total cholesterol, the molar ratio between serum PC and plasma cholesterol increased steadily after RYGB.

Conclusions

We conclude that changes in PC and apolipoproteins after RYGB are highly dynamic, reflecting a large plasticity and capability of accommodating lipid metabolism including PC-, cholesterol- and apolipoprotein metabolism imposed by RYGB surgery, independent of glucose tolerance. We suggest that after RYGB and major weight loss, PC and Apo A1 might have a special role in the altered metabolism of lipoproteins.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1111-7) contains supplementary material, which is available to authorized users.

Remission of Type 2 Diabetes Mellitus after Bariatric Surgery: Fact or Fiction?

Although type 2 diabetes mellitus (T2DM) has been traditionally viewed as an intractable chronic medical condition, accumulating evidence points towards the notion that a complete remission of T2DM is feasible following a choice of medical and/or surgical interventions. This has been paralleled by increasing interest in the establishment of a universal definition for T2DM remission which, under given circumstances, could be considered equivalent to a “cure”. The efficacy of bariatric surgery in particular for achieving glycemic control has highlighted surgery as a candidate curative intervention for T2DM. Herein, available evidence regarding available surgical modalities and the mechanisms that drive metabolic amelioration after bariatric surgery are reviewed. Furthermore, reports from observational and randomized studies with regard to T2DM remission are reviewed, along with concepts relevant to the variety of definitions used for T2DM remission and other potential sources of discrepancy in success rates among different studies.

Pros and cons of gastric bypass surgery in individuals with obesity and type 2 diabetes: nationwide, matched, observational cohort study

OBJECTIVES

Long-term effects of gastric bypass (GBP) surgery have been presented in observational and randomised studies, but there are only limited data for persons with obesity and type 2 diabetes mellitus (T2DM) regarding postoperative complications.

DESIGN

This is a nationwide observational study based on two quality registers in Sweden (National Diabetes Register, NDR and Scandinavian Obesity Surgery Register, SOReg) and other national databases.

SETTING

After merging the data, we matched individuals with T2DM who had undergone GBP with those not surgically treated for obesity on propensity score, based on sex, age, body mass index (BMI) and calendar time. The risks of postoperative outcomes (rehospitalisations) were assessed using Cox regression models.

PARTICIPANTS

We identified 5321 patients with T2DM in the SOReg and 5321 matched controls in the NDR, aged 18-65 years, with BMI >27.5 kg/m² and followed for up to 9 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

We assessed risks for all-cause mortality and hospitalisations for cardiovascular disease, severe kidney disease, along with surgical and other medical conditions.

RESULTS

The results agree with the previously suggested lower risks of all-cause mortality (49%) and cardiovascular disease (34%), and we also found positive effects for severe kidney disease but significantly increased risks (twofold to ninefold) of several short-term complications after GBP, such as abdominal pain and gastrointestinal conditions, frequently requiring surgical procedures, apart from reconstructive plastic surgery. Long-term, the risk of anaemia was 92% higher, malnutrition developed approximately three times as often, psychiatric diagnoses were 33% more frequent and alcohol abuse was three times as great as in the control group.

CONCLUSIONS

This nationwide study confirms the benefits and describes the panorama of adverse events after bariatric surgery in persons with obesity and T2DM. Long-term postoperative monitoring and support, as better selection of patients by appropriate specialists in interdisciplinary settings, should be provided to optimise the outcomes.

Non-pharmacological Treatment Options in the Management of Diabetes Mellitus

The global prevalence of diabetes, especially type 2 diabetes mellitus, has reached epidemic proportions in the last few decades of the 20th century because of the obesity pandemic resulting from adverse lifestyles. Diabetes as a consequence of obesity (diabesity), continues to increase exponentially in the 21st century. Although there are a multitude of drugs for the effective management of diabesity with modest benefits, most patients will require insulin for control of diabetes at some stage that would worsen obesity, and thereby diabesity. Therefore, effective non-pharmacological therapy needs to be expedited in all patients with diabesity. These measures include medical nutrition interventions, change of lifestyles and bariatric surgery. Non-pharmacological interventions are also useful for the effective management of even type 1 diabetes mellitus when used along with insulin therapy especially in those with obesity. This review summarises the current evidence base for the non-pharmacological interventions in the management of diabetes.