Weight loss achieved by bariatric surgery modifies high-density lipoprotein subfractions and low-density lipoprotein oxidation towards atheroprotection

Bariatric Surgery Outcomes in Patients with Severe Obesity Compared to Patients with Non-Severe Obesity at A New Institution in The United Arab Emirates

Background: Bariatric surgery is an effective treatment for weight loss, but a higher body mass index (BMI) may lead to higher postoperative complication rates. This study aims to compare perioperative and postoperative outcomes between UAE patients with severe obesity (SO) [BMI ≥ 50 kg/m2] and non-severe obesity (NSO) [BMI < 50 kg/m2] undergoing primary bariatric surgery. Methods: From September 2015 to July 2019, 542 patients, 94 SO (56.5 ± 6.2 kg/m2) and 448 NSO (41.8 ± 4.1 kg/m2), were retrospectively reviewed. Results: Patients with SO were younger (33.8 ± 13.4 vs. 37.0 ± 11.5 years, p = 0.02) but otherwise had similar demographic characteristics. Their rates of Roux-en-Y gastric bypass (39.4% SO vs. 44.4% NSO, p = 0.37) and sleeve gastrectomy (60.6% vs. 55.6%, p = 0.37) were similar. There were no differences between perioperative complications (6.4% SO vs. 5.8% NSO, p = 0.83), major postoperative complications (5.3% vs. 3.5%, p = 0.42), readmissions (5.3% vs. 3.3%, p = 0.36), or reoperations (3.2% vs. 2.7%, p = 0.78). There were no mortalities. Their total body weight loss was comparable at 12 months (28.1 ± 10.2% vs. 29.0 ± 7.7%, p = 0.58). Conclusions: Although a higher BMI may pose operative challenges, UAE patients with SO do not have worsened outcomes in bariatric surgery, demonstrating similarly low morbidity to patients with NSO, and similar rates of improvement in their BMI.

Advanced Lipoproteins and Lipidomic Profile in Plasma Determined by Nuclear Magnetic Resonance Before and After Bariatric Surgery

BACKGROUND

Obesity is related to cardiovascular risk factors (CVRF) such as dyslipidemia, diabetes, and hypertension, which increase mortality. Basic lipid determinations could underestimate the true atherogenic risk of patients and the impact of bariatric surgery. The objective of the study is to demonstrate the change in the advanced molecular profile of lipoproteins determined by nuclear magnetic resonance spectroscopy in plasma after bariatric surgery, thus reducing the risk of cardiovascular disease.

MATERIAL AND METHODS

Descriptive, observational, and prospective study in obese patients undergoing bariatric surgery. Advanced lipid profile was analyzed in plasma from the immediate preoperative period and at the 18th postoperative month by sending samples and performing plasma magnetic resonance spectroscopy in the BiosferTreslab® laboratory.

RESULTS

Fifty-two patients were included. Average age of 46.3 years; 63.46% were women, 36.54% men. The average BMI was 43.57; the abdominal perimeter 133.50 cm; 32.6% were diabetics under medical treatment, 44.23% hypertensive, and 19.23% smokers; 86.53% of the patients presented alterations in at least one of the analytical parameters in the lipid study. Twenty-nine (55.7%) underwent banded gastric bypass (PGB), 19.23% underwent GBP, and 17.31% vertical gastrectomy. The rest were revision surgeries, two BPG-A and two biliopancreatic diversions after GV. All patients presented some improvement in advanced molecular profile of lipoproteins. Twenty percent of the patients normalized all the parameters.

CONCLUSIONS

Bariatric surgery improves advanced molecular profile of lipoproteins, decreasing CVRF. Analysis of the characteristics of lipoprotein particles by NMR spectrometry is optimal for studying lipoprotein metabolism in patients undergoing bariatric surgery.

Effect of bariatric surgery on atherogenicity and insulin resistance in patients with obesity class II: a prospective study

OBJECTIVE

Enormous efforts have been made to evaluate reliable, simple and practical indicators for predicting patients at risk of progression of cardiovascular disease events, whereby bariatric surgery has remained understudied. Thus, we performed this study to assess the effect of bariatric surgery procedures on atherogenicity and insulin resistance indicators.

DESIGN

Cohort study.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

Four hundred and forty-three class II obese (severely obese) patients who underwent sleeve gastrectomy, Roux-en-Y gastric bypass, or one anastomosis gastric bypass were followed up for 12 months after surgery. Atherosclerosis-related indicators were evaluated at baseline, as well as 6 and 12 months after surgery.

RESULTS

Atherogenic index of plasma, lipoprotein combine index, atherogenic coefficient, cholesterol index, Castelli's risk indices I and II, and triglyceride to high-density lipoprotein-cholesterol ratio (p<0.01) improved after 12 months. Additionally, bariatric surgery yielded a significantly reduced triglyceride glucose index. There was no significant difference between procedures in terms of indicators. The Spearman correlation test showed a significant inverse correlation between weight plus fat mass and atherosclerosis-related indicators as well as a positive correlation between percentage of excess weight loss and these indicators.

CONCLUSIONS

This study demonstrated three bariatric surgery procedures' ability to improve atherogenicity and insulin resistance in patients with obesity class II. The anti-atherogenicity effects can be partly assigned to the reduction of body weight and adipose tissue. Nevertheless, further studies with larger sample sizes and longer follow-ups are required to confirm our results.

The Effect of Bariatric Surgery on Circulating Levels of Oxidized Low-Density Lipoproteins Is Apparently Independent of Changes in Body Mass Index: A Systematic Review and Meta-Analysis

Background

Obesity is related to dyslipidemia and increased circulating oxidated LDL (ox-LDL) concentrations that may predispose to atherosclerosis. Bariatric surgery may lower the risk of cardiovascular mortality. Elevated plasma ox-LDL has been associated with atherogenesis and atherosclerotic cardiovascular disease (ASCVD) events. The aim of this meta-analysis was to investigate the impact of bariatric surgery on proatherogenic circulating ox-LDL levels in patients with severe obesity.

Methods

Four databases were systematically searched from inception to May 1, 2021. Also, to clarify the heterogeneity of studies with regard to treatment duration, research design, and the demographic features, a random-effects model and the generic inverse variance weighting approach were utilized. To determine the association with the estimated effect size, a random-effect meta-regression approach was performed. Finally, a meta-regression analysis was conducted to explore the influence of, respectively, baseline and changes in body mass index (BMI), baseline ox-LDL, and postsurgery follow-up period with the estimated effect size of surgery on ox-LDL levels.

Results

Meta-analysis of 11 studies including 470 subjects showed a significant decline in circulating ox-LDL following bariatric surgery (SMD: -0.971, 95% CI: -1.317, -0.626, p < 0.001, I²: 89.43%). The results of meta-regression did not show any significant association between the changes in ox-LDL after bariatric surgery and baseline BMI, duration of follow-up or baseline ox-LDL values. However, there was a significant association between ox-LDL alteration and percentage of BMI change.

Conclusion

Bariatric surgery in patients who had severe obesity causes a decrease of circulating ox-LDL that was apparently dependent in BMI changes.

High-Density Lipoprotein Subfractions: Much Ado about Nothing or Clinically Important?

High-density lipoproteins (HDL) are a heterogenous group of plasma molecules with a large variety in composition. There is a wide specter in lipid content and the number of different proteins that has been associated with HDL is approaching 100. Given this heterogeneity and the fact that the total amount of HDL is inversely related to the risk of coronary heart disease (CHD), there has been increasing interest in the function of specific HDL subgroups and in what way measuring and quantifying these subgroups could be of clinical importance in determining individual CHD risk. If certain subgroups appear to be more protective than others, it may also in the future be possible to pharmacologically increase beneficial and decrease harmful subgroups in order to reduce CHD risk. In this review we give a short historical perspective, summarize some of the recent clinical findings regarding HDL subclassifications and discuss why such classification may or may not be of clinical relevance.

Subpopulations of High-Density Lipoprotein: Friends or Foes in Cardiovascular Disease Risk in Chronic Kidney Disease?

Dyslipidemia is a major traditional risk factor for cardiovascular disease (CVD) in chronic kidney disease (CKD) patients, although the altered lipid profile does not explain the number and severity of CVD events. High-density lipoprotein (HDL) is a heterogeneous (size, composition, and functionality) population of particles with different atherogenic or atheroprotective properties. HDL-cholesterol concentrations per se may not entirely reflect a beneficial or a risk profile for CVD. Large HDL in CKD patients may have a unique proteome and lipid composition, impairing their cholesterol efflux capacity. This lack of HDL functionality may contribute to the paradoxical coexistence of increased large HDL and enhanced risk for CVD events. Moreover, CKD is associated with inflammation, oxidative stress, diabetes, and/or hypertension that are able to interfere with the anti-inflammatory, antioxidative, and antithrombotic properties of HDL subpopulations. How these changes interfere with HDL functions in CKD is still poorly understood. Further studies are warranted to fully clarify if different HDL subpopulations present different functionalities and/or atheroprotective effects. To achieve this goal, the standardization of techniques would be valuable.

Changes in the Composition and Function of Lipoproteins after Bariatric Surgery in Patients with Severe Obesity

The effect of bariatric surgery on lipid profile and the qualitative characteristics of lipoproteins was analyzed in morbidly obese subjects. Thirteen obese patients underwent bariatric surgery. Plasma samples were obtained before surgery and at 6 and 12 months after the intervention. Thirteen healthy subjects comprised the control group. Lipid profile, hsCRP, and the composition and functional characteristics of VLDL, LDL, and HDL were assessed. At baseline, plasma from subjects with obesity had more triglycerides, VLDLc, and hsCRP, and less HDLc than the control group. These levels progressively normalized after surgery, although triglyceride and hsCRP levels remained higher than those in the controls. The main differences in lipoprotein composition between the obese subjects and the controls were increased apoE in VLDL, and decreased cholesterol and apoJ and increased apoC-III content in HDL. The pro-/anti-atherogenic properties of LDL and HDL were altered in the subjects with obesity at baseline compared with the controls, presenting smaller LDL particles that are more susceptible to modification and smaller HDL particles with decreased antioxidant capacity. Bariatric surgery normalized the composition of lipoproteins and improved the qualitative characteristics of LDL and HDL. In summary, patients with obesity present multiple alterations in the qualitative properties of lipoproteins compared with healthy subjects. Bariatric surgery reverted most of these alterations.

Cardiovascular Risk Reduction Following Metabolic and Bariatric Surgery

Cardiovascular disease (CVD) remains a leading cause of morbidity and mortality in developed countries, with worsening pandemics of type 2 diabetes mellitus and obesity as major cardiovascular (CV) risk factors. Clinical trials of nonsurgical obesity treatments have not shown benefits in CVD, although recent diabetes trials have demonstrated major CV benefits. In many retrospective and prospective cohort studies, however, metabolic (bariatric) surgery is associated with substantial and reproducible CVD benefits. Despite a lack of prospective, randomized clinical trials, data suggest metabolic surgery may be the most effective modality for CVD risk reduction, likely through weight loss and weight loss-independent mechanisms.

Impact of a 2-year trial of nutritional ketosis on indices of cardiovascular disease risk in patients with type 2 diabetes

BACKGROUND

We have previously reported that in patients with type 2 diabetes (T2D) consumption of a very low carbohydrate diet capable of inducing nutritional ketosis over 2 years (continuous care intervention, CCI) resulted in improved body weight, glycemic control, and multiple risk factors for cardiovascular disease (CVD) with the exception of an increase in low density lipoprotein cholesterol (LDL-C). In the present study, we report the impact of this intervention on markers of risk for atherosclerotic cardiovascular disease (CVD), with a focus on lipoprotein subfraction particle concentrations as well as carotid-artery intima-media thickness (CIMT).

METHODS

Analyses were performed in patients with T2D who completed 2 years of this study (CCI; n = 194; usual care (UC): n = 68). Lipoprotein subfraction particle concentrations were measured by ion mobility at baseline, 1, and 2 years and CIMT was measured at baseline and 2 years. Principal component analysis (PCA) was used to assess changes in independent clusters of lipoprotein particles.

RESULTS

At 2 years, CCI resulted in a 23% decrease of small LDL IIIb and a 29% increase of large LDL I with no change in total LDL particle concentration or ApoB. The change in proportion of smaller and larger LDL was reflected by reversal of the small LDL subclass phenotype B in a high proportion of CCI participants (48.1%) and a shift in the principal component (PC) representing the atherogenic lipoprotein phenotype characteristic of T2D from a major to a secondary component of the total variance. The increase in LDL-C in the CCI group was mainly attributed to larger cholesterol-enriched LDL particles. CIMT showed no change in either the CCI or UC group.

CONCLUSION

Consumption of a very low carbohydrate diet with nutritional ketosis for 2 years in patients with type 2 diabetes lowered levels of small LDL particles that are commonly increased in diabetic dyslipidemia and are a marker for heightened CVD risk. A corresponding increase in concentrations of larger LDL particles was responsible for higher levels of plasma LDL-C. The lack of increase in total LDL particles, ApoB, and in progression of CIMT, provide supporting evidence that this dietary intervention did not adversely affect risk of CVD.

Obesity-Related Changes in High-Density Lipoprotein Metabolism and Function

In obese individuals, atherogenic dyslipidemia is a very common and important factor in the increased risk of cardiovascular disease. Adiposity-associated dyslipidemia is characterized by low high-density lipoprotein cholesterol (HDL-C) levels and an increase in triglyceride-rich lipoproteins. Several factors and mechanisms are involved in lowering HDL-C levels in the obese state and HDL quantity and quality is closely related to adiponectin levels and the bioactive lipid sphingosine-1-phosphate. Recent studies have shown that obesity profoundly alters HDL metabolism, resulting in altered HDL subclass distribution, composition, and function. Importantly, weight loss through gastric bypass surgery and Mediterranean diet, especially when enriched with virgin olive oil, is associated with increased HDL-C levels and significantly improved metrics of HDL function. A thorough understanding of the underlying mechanisms is crucial for a better understanding of the impact of obesity on lipoprotein metabolism and for the development of appropriate therapeutic approaches. The objective of this review article was to summarize the newly identified changes in the metabolism, composition, and function of HDL in obesity and to discuss possible pathophysiological consequences.

Effect of sleeve gastrectomy on lipid parameters and cardiometabolic risk in young women

OBJECTIVE

to analyze the effect of vertical gastrectomy on lipid profile and cardiometabolic risk in young women, preoperatively and 6 months after the operation.

METHODS

retrospective study, encompassing medical record reviews of women's charts, preoperatively and in six months after the operation. Data collection was performed in the second half of 2015, using a review protocol with questions on the clinical-laboratory profile, anthropometric and laboratory classification of dyslipidemias. Descriptive and inferential analysis were used to treat the variables, using measures of variance, association and linear regression.

RESULTS

we analyzed medical records of 114 women undergoing vertical gastrectomy, with a mean age of 33.82±10.92, and with complete high school education. There was a significant reduction of anthropometric data, as well as serum lipid values, six months after the surgical procedure. The coefficients of determination and the results of linear regression, showed that the reduction in serum triglyceride values and increase in high-density lipoprotein have a direct impact on the reduction of the cardiometabolic risk. Regarding the laboratory classification of dyslipidemias, it was observed that the majority presented a significant reduction at the six-month follow-up. Mixed hyperlipidemia showed no significant reduction. The categorized cardiometabolic risk showed a significant reduction in women at risk before vertical gastrectomy.

CONCLUSION

at the six-month follow-up, vertical gastrectomy was effective in reducing the serum lipid profile and the cardiometabolic risk of young women when compared to the preoperative data. There was also a different improvement in the laboratory classification of dyslipidemias at the six-month follow-up after the surgical procedure.

Bariatric Surgery Improves HDL Function Examined by ApoA1 Exchange Rate and Cholesterol Efflux Capacity in Patients with Obesity and Type 2 Diabetes

Bariatric surgery improves glycemic control better than medical therapy; however, the effect of bariatric surgery on HDL function is not well characterized. Serum samples were available at baseline, 1-, and 5-years post procedures, for 90 patients with obesity and type 2 diabetes who were randomized to intensive medical therapy (n = 20), Roux-en-Y gastric bypass (RYGB, n = 37), or sleeve gastrectomy (SG, n = 33) as part of the STAMPEDE clinical trial. We examined serum HDL function by two independent assays, apolipoprotein A-1 exchange rate (AER) and cholesterol efflux capacity (CEC). Compared with baseline, AER was significantly higher at 5 years for participants in all treatment groups, but only increased significantly at 1 year in the RYGB and SG groups. CEC was divided into ABCA1-dependent and independent fractions, and the later was correlated with AER. ABCA1-independent CEC increased significantly only at 5 years in both surgical groups, but did not significantly change in the medical therapy group. There was no significant change in ABCA1-dependent CEC in any group. The increase in AER, but not ABCA1-independent CEC, was correlated with the reduction in body mass index and glycated hemoglobin levels among all subjects at 5 years, indicating that AER as a measure of HDL function would be a better reflection of therapy versus CEC.

Effect of laparoscopic sleeve gastrectomy on renal function in obese patients

BACKGROUND

To investigate the clinical efficacy and mechanism of laparoscopic sleeve gastrectomy (LSG) in improving renal function in obese patients.

METHODS

We retrospectively reviewed the anthropometric indices (waist circumference, hip circumference and body mass index (BMI)), renal function indices (serum creatinine, urea and urinary albumin:creatinine ratio (UACR)), serum inflammatory indices (C-reactive protein, interleukin-6 and tumour necrosis factor-α) and an adipose factor (leptin) in 50 patients with obesity (BMI ≥32.5 kg/m² ) who underwent LSG in our hospital from January 2018 to January 2019.

RESULTS

Patients constituted 23 men and 27 women, with an average age of 32.5 ± 8.7 years and BMI of 43.99 ± 8.29 kg/m² . Body weight and BMI 1 month post-operatively were significantly lower than preoperatively (P < 0.05), and the renal function indices serum creatinine, urea and UACR, improved significantly 3 months post-operatively (P < 0.05). C-reactive protein, interleukin-6 and tumour necrosis factor-α levels improved significantly 3 months post-operatively (P < 0.05), while leptin levels decreased significantly 1 month post-operatively (P < 0.05). Six months post-operatively, the remission rates for type 2 diabetes mellitus, sleep apnoea syndrome and hypertension were 83.8%, 92.9% and 88.6%, respectively.

CONCLUSIONS

LSG led to body weight loss and significantly improved serum creatinine, urea and UACR values in patients with obesity, which may be related to changes in adipocytokines and inflammatory factors, post-operatively. LSG is expected to become a new treatment to prevent or treat renal insufficiency caused by obesity.

Effect of 8-weeks intensive lifestyle intervention on LDL and HDL subfractions

OBJECTIVE

Atherogenic dyslipidemia is a cardinal feature of obesity and the metabolic syndrome, which increases the risk of cardiovascular diseases. Many interventional studies, describing the influence of weight loss on cardiometabolic risks, are bariatric surgery studies. The aim of our study was to analyze the effect of intensive lifestyle changes on LDL- and HDL-cholesterol subfractions and cardiometabolic risk factors in obese subjects.

METHODS

A group of 41 patients with obesity (11M/30F; 44.1±12.4 years; BMI 30.2±6.3kg/m²) participated in an 8-week weight loss interventional program (NCT02325804), consisting of caloric intake reduced by 30% and physical activity (150min/week). Insulin sensitivity was evaluated according to the homeostasis model assessment of insulin resistance (HOMA-IR) and physical fitness was measured using bicycle ergometry. Lipid subfractions were measured using the Lipoprint system (Quantimetrix Corp., CA, USA).

RESULTS

After the intervention, body weight was reduced by 5.4±4.5kg, as well as body fat mass and waist circumference. Physical fitness improved, systolic and diastolic blood pressure as well as heart rate decreased after the intervention. Insulin sensitivity improved after the intervention. Total, LDL, HDL cholesterol, as well as triglycerides decreased after the intervention. Regarding the lipoprotein subfractions, LDL2 and small HDL subfractions decreased, while others have not changed.

CONCLUSION

Eight weeks of diet and physical activity intervention led to weight and fat mass loss and induced improvement of insulin sensitivity, as well as atheroprotective changes of lipid profile. However, the weight loss associated changes in cholesterol subfractions as cardiovascular risk biomarkers deserve further studies.

Physical Exercise and Grip Strength in Patients Intervened through Bariatric Surgery

Objective: This work sought to evaluate a physical exercise program of moderate intensity in patients operated of bariatric surgery and its influence on muscle strength. Method: Randomized clinical trial, with an intervention group and a control group. Forty-three patients were operated of bariatric surgery. The intervention group was applied a program of moderate physical activity during six months. Grip strength and bioimpedance were measured at their baseline form, at one month, and six months after surgery. A bivariate study was conducted to observe variable changes. Results: Upon conducting Student´s t for independent samples in all the variables (weight, body mass index, grip strength, lean mass, fat mass, and metabolism), the result is that no significant differences exist between the intervention group and the control group with p > 0.05. Conclusion: A program of moderate physical activity lasting six months in patients intervened of bariatric surgery has no significant result in the development of muscle mass evaluated through manual dynamometry and bioimpedance.