Effects of Bariatric Surgery on HDL Cholesterol

Postoperative Biochemical Outcomes in Metabolic Bariatric Surgery: Results from a High-Adherence Cohort

BACKGROUND/OBJECTIVES

In metabolic bariatric surgery, structured follow-up protocols may play an essential role in achieving optimal patient outcomes. This study aims to report postoperative biochemical outcomes in a cohort of post-bariatric patients who underwent a structured follow-up protocol.

METHODS

This retrospective study included patients who underwent metabolic bariatric surgery and completed a one-year follow-up at Cannizaro Hospital from October 2022 to May 2024. Anthropometric, clinical, and laboratory data were collected for each patient at five different timepoints: baseline, 1, 3, 6, and 12 months post-surgery. All data were organized into a database and analyzed through descriptive statistics.

RESULTS

The study cohort (n = 80) showed a follow-up adherence equal to 97.5%. The mean value of BMI decreased from 42 to 27 one year after surgery. Lipid profiles improved, with significant reduction in total cholesterol and triglycerides and increase in HDL levels; LDL levels decreased initially but at one year returned to baseline. Thyroid hormones TSH and fT3 decreased significantly, while fT4 remained stable. A reduction in hepatic inflammation was observed, as evidenced by the decrease in GGT and transaminase levels. Pancreatic enzymes showed an initial increase but stabilized at the subsequent timepoints. Glycemic control improved, with statistically significant reductions in insulin, HbA1c, and glucose levels, and complete remission of type 2 diabetes mellitus in affected patients.

CONCLUSIONS

This study shows significant weight loss and improved health outcomes in post-bariatric patients who underwent a structured follow-up protocol, suggesting the potential benefits of metabolic bariatric surgery.

Bariatric Surgery and Metabolic Status

Background and Objectives: Obesity is associated with numerous co-morbidities, including dyslipidemia, insulin resistance and diabetes mellitus. Bariatric surgery is the mainstay of treatment for obesity as the only method with confirmed long-term effects in weight reduction and the remission of comorbidities. Postoperative recommendations leading to changes in dietary habits and changes in digestion and absorption in the gastrointestinal tract after bariatric surgery may additionally influence the levels of laboratory parameters that reflect the metabolic and nutritional status. The purpose of the study was to analyze the possible influence of changes in dietary habits after bariatric surgery on those laboratory results that reflect the metabolic and nutritional status. Materials and Methods: This was a retrospective study of 88 patients with a history of bariatric surgery. Data were gathered from before the surgery and at 6 months after the surgery and included diet structure and selected laboratory parameters reflecting the metabolic and nutritional status, i.e., levels of fasting glucose, glycated hemoglobin, cholesterol, low- and high-density lipoproteins, triglycerides, alanine and aspartate aminotransferases, proteins, ferrum, ferritin, vitamin B12, folic acid, vitamin D and calcium, the red blood cell count and the hematocrit. Results: Postoperative festive glucose levels were reduced by 14% and were more significant in patients after Roux-en-Y gastric bypass. There was an increase of 22% in concentrations of high-density lipoproteins. Triglyceride concentrations were reduced by 32%. Aminotransferase levels decreased by 43% for alanine aminotransferase and by 14% for aspartate aminotransferase. Among the changes in dietary habits, post-bariatric patients had a reduced consumption of red meat and an increased consumption of fish, milk and dairy products and wholegrain products. Vitamin D and ferrum levels were higher after the surgery, whereas vitamin B12 and folic acid levels remained unchanged. Conclusions: Improved dietary habits of patients after bariatric surgery may lead to changes in laboratory parameters that reflect the ameliorated metabolic and nutritional status of patients after bariatric surgery.

Weight loss benefits on HDL cholesterol persist even after weight regaining

BACKGROUND

Obesity-related comorbidities may relapse in patients with weight regain after bariatric surgery. However, HDL cholesterol (HDLc) levels increase after surgery and seem to remain stable despite a gradual increase in BMI. The aim of this study is to analyze the effects of weight regain after bariatric surgery on HDL cholesterol.

MATERIALS AND METHODS

This is a retrospective, observational, cohort study in patients who underwent bariatric surgery in the Hospital de la Santa Creu i Sant Pau (Barcelona) between 2007 and 2015. Patients without at least 5 years of follow-up after surgery, under fibrate treatment, and those who required revisional surgery were excluded from the analysis. Data were collected at baseline, 3 and 6 months after surgery, and then annually until 5 years post-surgery.

RESULTS

One hundred fifty patients were analyzed. 93.3% of patients reached > 20% of total weight loss after surgery. At 5th year, 37% of patients had regained > 15% of nadir weight, 60% had regained > 10%, and 22% had regained < 5% of nadir weight. No differences were found in HDLc levels between the different groups of weight regain, nor in the % of change in HDLc levels between nadir weight and 5 years, or in the proportion of patients with normal HDLc concentrations either.

CONCLUSION

HDLc remains stable regardless of weight regain after bariatric surgery.

Effects of laparoscopic sleeve gastrectomy on thyroid hormones and relationship between metabolic parameters and long-term total weight loss

BACKGROUND

Bariatric surgery has significant effects on metabolic parameters and hormone levels. However, the specific impact of laparoscopic sleeve gastrectomy (LSG) on thyroid hormones and other metabolic parameters remains unclear. This study aimed to investigate the short and long-term effects of LSG on thyroid hormone levels, HbA1c, and other metabolic parameters.

METHODS

A total of 619 euthyroid patients without a history of thyroid disease or thyroid hormone replacement therapy were included in the study. Patients with diabetes were excluded from the study. Preoperative, 1-year postoperative, and 5-year postoperative levels of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), HbA1c, and other metabolic parameters were recorded and analyzed.

RESULTS

LSG resulted in significant weight loss and improvements in metabolic parameters. At 1 year postoperatively, there were significant reductions in BMI, HbA1c, TSH, fT3, and triglyceride levels, while fT4 levels increased. A statistically significant negative correlation was found between preoperative HbA1c level and percentage of total weight loss (%TWL) value at the fifth postoperative year. Additionally, a statistically significant negative correlation was found between the 5-year change in TSH and %TWL.

CONCLUSION

Being the first study to predict long-term total weight loss based on preoperative HbA1c, it is significant. This finding has important implications for personalized patient management and could aid clinicians in identifying individuals who may benefit most from sleeve gastrectomy as a treatment modality. This is valuable in that it emphasizes multidisciplinary work, including the endocrinologist and dietician.

Inflammatory and metabolic markers and comorbidities remission following sleeve gastrectomy: A single center one-year cohort study

BACKGROUND AND AIM

Obesity is a global concern with several health-related complications. Bariatric surgeries are major treatment options in patients with obesity and other comorbidities. This study aims to investigate the effects of sleeve gastrectomy on metabolic indexes, hyperechogenic liver changes, inflammatory state, diabetes, and other obesity-related comorbidities remission after the sleeve gastrectomy.

METHODS

This prospective study was conducted on patients with obesity candidates for laparoscopic sleeve gastrectomy. Patients were followed for one year after the surgery. Comorbidities, metabolic and inflammatory parameters were assessed before and one- year after the surgery.

RESULTS

137 patients (16 males, 44 in the DM group) underwent sleeve gastrectomy. One year after the study, obesity-related comorbidities improved significantly; diabetes had complete remission in 22.7% and partial remission in 63.6% of patients. Hyper-cholesterolemia, hyper-triglyceridemia, and hyper-uricemia also improved in 45.6%, 91.2%, and 69% of the patients. Metabolic syndrome indexes improved in 17.5% of the patients. Also, the prevalence of hyperechogenic changes in the liver has declined from 21% before the surgery to 1.5% after that. Based on logistic regression analysis, increased levels of HbA1C reduced the chance of diabetes remission by 0.9%. In comparison, every unit of increased BMI before the surgery improved the case of diabetes remission by 16%.

CONCLUSION

Laparoscopic sleeve gastrectomy is a safe and effective treatment option in patients with obesity and diabetes. Laparoscopic sleeve gastrectomy alleviates BMI and insulin resistance and effectively improves other obesity-related comorbidities such as Hypercholesterolemia, hyper-triglyceridemia, hyper-uricemia, and hyperechogenic changes of the liver. HbA1C and BMI before the surgery are notable predictors of diabetes remission within the first year after the surgery.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

The impact of bariatric surgery procedures on the modulation of cardiometabolic risk factors in patients with severe obesity: a 12-month follow-up

OBJECTIVE

To evaluate the effects of one anastomosis gastric bypass (OAGB), Roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy (SG) on cardiometabolic risk factors (CMRFs) in patients with severe obesity.

METHODS

This retrospective cohort study included patients with severe obesity who had undergone OAGB, RYGB, or SG between 2015 and 2017 and follow-up assessments over 12-months.

RESULTS

Among 485 included patients, anthropometric measurements, body composition, fasting blood glucose (FBG), lipid profile, and comorbidities were significantly improved for all three procedures throughout the follow-up period. Weight, % total weight loss (%TWL), body mass index, fat mass and fat mass to fat-free mass ratio improvements were higher with RYGB and OAGB than SG. There were no significant differences between procedures in all other variables. A significant trend toward remission rate of dyslipidemia and type 2 diabetes mellitus was observed with all three procedures, with no significant difference between the three groups. %TWL statistically correlated with fat mass, FBG, and triglycerides.

CONCLUSIONS

OAGB, RYGB, and SG had a beneficial impact on CMRFs and comorbidities during 12 months of follow-up. Of note, RYGB and OAGB may result in better outcomes, particularly anthropometric and body composition indices. Further large-sample, long-term follow-up studies are required to expand on the present findings.

Lipocalin, Resistin and Gut Microbiota-Derived Propionate Could Be Used to Predict Metabolic Bariatric Surgery Selected Outcomes

Many patients with clinically severe obesity (CSO) need to undergo bariatric surgery, with possible side effects, so individualized predictive methods are required. Adipocytokines and gut/intestinal microbiota-derived metabolites could be predictive biomarkers of metabolic success post- surgery, but the knowledge in this field is undefined. The objective of this work was to determine whether adipocytokines and microbiota-derived metabolites can be used to predict the metabolic improvement post- surgery in women with CSO. We analyzed circulating levels of some cytokines and some microbiota-derived metabolites at baseline and 12 months post-surgery from 44 women with CSO and 21 women with normal weight. Results showed that glucose, insulin, glycosylated hemoglobin A1c (HbA1c), low-density lipoprotein (LDL-C), and triglycerides levels were decreased post-surgery, while high density lipoprotein increased. Twelve months later, leptin, resistin, lipocalin, PAI-1, TNF-α, and IL-1β levels were lower than baseline, meanwhile adiponectin, IL-8, and IL-10 levels were increased. Moreover, baseline lipocalin levels were associated with HbA1c reduction post-surgery; meanwhile baseline resistin was related to postoperative HOMA2 (insulin resistance) and baseline propionate was associated with LDL-C decrease. To conclude, the detection of lipocalin, resistin, and propionate levels may be used to predict the metabolic success following bariatric surgery, although new knowledge is needed.

Evaluation of Lipoprotein Profile and Residual Risk Three Years After Bariatric Surgery

INTRODUCTION

Obesity is a chronic disease associated with other comorbidities, including atherogenic dyslipidemia (AD). Bariatric surgery (BS) has shown to reduce cardiovascular risk (CVR) by achieving a significant weight reduction and improving the lipid profile. Different surgical techniques may have a different effect on the lipoprotein profile.

PURPOSE

To evaluate the lipid profile at 3 years after BS according to the surgical technique used and to determine which variables predict variation in the lipid profile at 3 years after BS.

METHODS

Retrospective observational study of 206 patients who underwent BS between 2010 and 2019. We analyzed the variation of lipid parameters in the 3 years of follow-up according to the surgical technique, including a group analysis of patients according to whether they had dyslipidemia and whether they were treated or untreated and determined which variables predict variation in the lipid profile at 3 years after BS.

RESULTS

There was a significant increase in high-density lipoprotein cholesterol (HDL-c) with sleeve gastrectomy (SG) and a significant decrease in total cholesterol (TC), LDL-cholesterol (LDL-c), non-HDL, and LDL/non-HDL with biliopancreatic diversion (BPD). Variables predicting lipid profile variation were surgical technique and pre-surgery lipoprotein level.

CONCLUSIONS

Malabsorptive techniques achieve a greater decrease in TC and LDL-c throughout follow-up and could also improve residual cardiovascular risk (non-HDL and LDL/non-HDL). The type of surgical technique and the presurgery lipid profile predict variation after 3 years of BS.

HDL Dysfunctionality: Clinical Relevance of Quality Rather Than Quantity

High-density lipoproteins (HDLs) represent a class of lipoproteins very heterogeneous in structure, composition, and biological functions, which carry out reverse cholesterol transport, antioxidant, anti-inflammatory, antithrombotic, and vasodilator actions. Despite the evidence suggesting a clear inverse relationship between HDL cholesterol (HDL-c) concentration and the risk for cardiovascular disease, plasma HDL cholesterol levels do not predict the functionality and composition of HDLs. The importance of defining both the amount of cholesterol transported and lipoprotein functionality has recently been highlighted. Indeed, different clinical conditions such as obesity, diabetes mellitus type 2 (T2DM), and cardiovascular disease (CVD) can alter the HDL functionality, converting normal HDLs into dysfunctional ones, undergoing structural changes, and exhibiting proinflammatory, pro-oxidant, prothrombotic, and proapoptotic properties. The aim of the current review is to summarize the actual knowledge concerning the physical-chemical alteration of HDLs related to their functions, which have been found to be relevant in several pathological conditions associated with systemic inflammation and oxidative stress.

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.

Al-Dirbashi O, Alkaabi J. Metabolomic Profiling of Lipids and Fatty Acids: 3 Years Postoperative Laparoscopic Sleeve Gastrectomy

Visceral obesity is common in the United Arab Emirates and worldwide. Although laparoscopic sleeve gastrectomy (LSG) leads to effective and sustainable weight loss, its long-term beneficial impact on other risk factors, including blood lipid and fatty acid (FA) profiles, remains unknown. These two profiles were assessed in patients 3 years after undergoing LSG and in LSG candidates (controls). Lipid profiles were measured using the Cobas e411 modular analyzer, and 35 FAs were identified. The age and body mass index were 36.55 ± 8.65 years and 31.49 ± 6.43 kg/m2 in the LSG group and 35.44 ± 9.51 years and 32.29 ± 5.38 kg/m2 in the control group, respectively. The overall lipid profile was more favorable in the LSG group than in the control group. Total saturated, monounsaturated, and polyunsaturated FAs were similar between the groups, but total medium-chain FAs were more abundant in the LSG group. In endogenous FA synthesis, the estimated activity of C16Δ9 desaturase and Δ5 desaturase decreased, whereas that of elongase increased in the LSG group compared with that in the control group. The benefits of LSG on blood lipid and FA profiles in patients with 3-year LSG may be limited. Hence, lifestyle interventions combined with a long-term and strict regular follow-up regime may be warranted for patients undergoing LSG.

Decreased Triglyceride and Increased Serum Lipoprotein Lipase Levels Are Correlated to Increased High-Density Lipoprotein-Cholesterol Levels after Laparoscopic Sleeve Gastrectomy

INTRODUCTION

Laparoscopic sleeve gastrectomy (LSG) significantly increases high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL) in pre-heparin serum (pre-heparin LPL levels). LPL is a regulator of serum triglyceride (TG) and HDL-C production; this may be the mechanism for HDL-C increase after LSG. This study aimed to elucidate the mechanism of increase in HDL-C levels by examining the relationship between changes in serum HDL-C levels and LPL after LSG.

METHODS

We retrospectively reviewed 104 obese patients, who underwent LSG and were followed up for 12 months. We analyzed the relationship between changes in serum HDL-C levels and various clinical parameters after LSG.

RESULTS

A significant decrease was observed in the patients' BMI and serum TG levels after LSG. Conversely, HDL-C levels and pre-heparin LPL levels were significantly increased after LSG. Simple linear regression showed that changes in HDL-C levels were significantly correlated with total weight loss percentage, change in TG levels, abdominal fat areas, and pre-heparin LPL levels. Additionally, the multiple regression model revealed that a decrease in TG levels and an increase in pre-heparin LPL levels were correlated with increased HDL-C levels after LSG.

DISCUSSION/CONCLUSION

These results show that a decrease in TG levels and an increase in LPL are mechanisms for increased HDL-C levels after LSG.

Short-term multiorgan metabolic benefits of rapid weight loss after sleeve gastrectomy in severely obese patients

BACKGROUND

Sleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.

OBJECTIVE

Comprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.

SETTING

Academic hospital, United States.

METHODS

We retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.

RESULTS

A total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.

CONCLUSION

There are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy.