Impact of bariatric surgery on apolipoprotein C-III levels and lipoprotein distribution in obese human subjects

The Impact of Metabolic and Bariatric Surgery on Apo B100 Levels in Individuals with high BMI: A Multi-Centric Prospective Cohort Study

BACKGROUND

Metabolic and Bariatric surgery (MBS) leads to significant weight loss and improvements in obesity-related comorbidities. However, the impact of MBS on Apolipoprotein B100 (Apo-B100) regulation is unclear. Apo-B100 is essential for the assembly and secretion of serum lipoprotein particles. Elevated levels of these factors can accelerate the development of atherosclerotic plaques in blood vessels. This study aimed to evaluate changes in Apo-B100 levels following MBS.

METHODS

121 participants from the Iranian National Obesity and Metabolic Surgery Database (INOSD) underwent Laparoscopic Sleeve Gastrectomy (LSG) (n = 43), One-Anastomosis Gastric Bypass (OAGB) (n = 70) or Roux-en-Y Gastric Bypass (RYGB) (n = 8). Serum Apo-B100, lipid profiles, liver enzymes, and fasting glucose were measured preoperatively and six months postoperatively.

RESULTS

Apo-B100 levels significantly decreased from 94.63 ± 14.35 mg/dL preoperatively to 62.97 ± 19.97 mg/dL after six months (p < 0.01), alongside reductions in total cholesterol, triglycerides, LDL, VLDL, AST, and ALT (p < 0.05). Greater Apo-B100 reductions occurred in non-diabetics versus people with diabetes (p = 0.012) and strongly correlated with baseline Apo-B100 (r = 0.455, p < 0.01) and LDL levels (r = 0.413, p < 0.01). However, surgery type did not impact Apo-B100 changes in multivariate analysis (p > 0.05).

CONCLUSION

Bariatric surgery leads to a significant reduction in Apo-B100 levels and improvements in lipid profiles and liver enzymes, indicating a positive impact on dyslipidemia and cardiovascular risk in individuals with high BMI.

Hyperlipidaemia in diabetes: are there particular considerations for next-generation therapies?

Dyslipidaemias are major cardiovascular risk factors, especially in people with diabetes. In this area, next-generation therapies targeting circulating lipoparticle metabolism (LDL, VLDL, chylomicrons, HDL) have recently been approved by the European and US medical agencies, including anti- proprotein convertase subtilisin/kexin 9 (PCSK9) antibodies; an siRNA targeting PCSK9; bempedoic acid, which targets ATP citrate lyase; an antisense oligonucleotide targeting apolipoprotein C-III; an anti-angiopoietin-like 3 antibody; and a purified omega-3 fatty acid, icosapent ethyl. Other therapies are in different phases of development. There are several important considerations concerning the link between these new lipid-lowering therapies and diabetes. First, since concerns were first raised in 2008 about an increased risk of new-onset diabetes mellitus (NODM) with intensive statin treatment, each new lipid-lowering therapy is being evaluated for its associated risk of NODM, particularly in individuals with prediabetes (impaired fasting glucose and/or impaired glucose tolerance). Second, people with diabetes represent a large proportion of those at high or very high cardiovascular risk in whom these lipid-lowering drugs are currently, or will be, prescribed. Thus, the efficacy of these drugs in subgroups with diabetes should also be closely considered, as well as any potential effects on glycaemic control. In this review, we describe the efficacy of next-generation therapies targeting lipoprotein metabolism in subgroups of people with diabetes and their effects on glycaemic control in individuals with diabetes and prediabetes and in normoglycaemic individuals.

Recurrent Hypertriglyceridemia-Induced Pancreatitis due to Multifactorial Chylomicronemia Syndrome in a Patient With Ketosis-Prone Diabetes Mellitus

The triad of diabetic ketoacidosis (DKA), severe hypertriglyceridemia, and acute pancreatitis have been occasionally described in severely obese patients with type 2 diabetes mellitus (T2DM). Herein, we present a long-term clinical course of a Thai man with ketosis-prone diabetes mellitus (KPDM) complicated with recurrent pancreatitis due to multifactorial chylomicronemia syndrome. Genetic testing showed no mutation in lipoprotein lipase (LPL) and its co-factors. The patient was referred to multidisciplinary team for lifelong weight loss consultation, limiting intake of fat and simple carbohydrates, and adherence to lipid-lowering medications. Subsequent follow-up 1 year later showed no recurrent pancreatitis. In patients with multifactorial chylomicronemia syndrome, long-term management with dietary modifications together with pharmacotherapy remains the cornerstone of successful treatment.

Selective effect of laparoscopic Roux-en-Y gastric bypass on lipid metabolism

INTRODUCTION

Bariatric surgery (BS) has shown to reduce cardiovascular morbidity and mortality in obesity. The BS has improved the dyslipidemia of the insulin resistant patient, our objective was to evaluate if there was a difference in the lipid profile between the laparoscopic roux-en-Y gastric bypass (RYGB) technique vs. the sleeve gastrectomy (SG) technique at 18 months of follow-up.

METHODS

An observational, open, prospective study of morbidly obese patients who underwent bariatric surgery at 18-month follow-up. Anthropometric analysis, body composition, energy expenditure at rest, glucose, insulin, HbA_1c, LDL, HDL, TG and CT were performed.

RESULTS

Absence baseline differences were found in the proportion of patients with hypertension, diabetes, steatosis, and sex between the RYGB vs SG groups. A reduction of TG was observed at 6 months in favor of RYGB vs SG: 108.60±34.86 vs. 124.59±44.58, P = 0.044), however, a decrease in both LDL levels was found at 12 and 18 months in favor of the RYGB vs. SG group: 96.23±24.33 vs. 107.83±28.88, P = 0.025; 90.98±20.62 vs 106.22±31.48, P = 0.003; the decrease in CT was observed only at 18 months in favor of the RYGB vs. SG group: 171.39±25.058 vs. 186.89±31.81, P = 0.005. CONCLUSIóN: RYBG has shown to be more effective in reducing LDL and CT levels compared to SG, which provides an additional benefit of RYGB in relation to the lipid profile of the patient.

Correlation of Bariatric Surgery Effect on Lipid Profile Among Obese Patients

Background

A considerable subpopulation of patients with morbid obesity present with dyslipidemia. It is characterized by elevated total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and low high-density lipoprotein (HDL) concentrations. Sleeve gastrectomy (SG) is considered a method of treating morbid obesity and associated dyslipidemia.

Objective

To assess the effect of bariatric and metabolic surgery on lipid profile of morbidly obese patients.

Methods

We used a retrospective approach analyzing the lipid profiles of patients who underwent SG between January 2018 and July 2020. Patients were enrolled according to age (>17 years), pre-operative body mass index (BMI; >30 kg/m²), undergoing SG, and having complete follow-up records of lipid profiles. Baseline and post-operative lipid profiles, their variation, and the percentage of variation were compared.

Results

We analyzed data of 163 patients who underwent SG. The mean age was 36.75 ± 10.75 years, the mean BMI was 45.66 ±8.46, and the mean pre-operative TC, LDL, HDL, and TG were 4.67 ± 1.02, 2.55 ± 1.1, 1.14 ± 0.32, and 1.5 ± 1.11, respectively. There was a significant change in the mean level of TG as it was significantly higher pre-operatively compared to its mean level post-operatively. Furthermore, a significant change was observed in HDL. There was a non-significant change in levels of TC and LDL post-operatively.

Conclusion

SG showed to significantly reduce TG and elevate HDL in morbidly obese patients. On the contrary, TC and LDL were non-significantly affected. Further studies with longer follow-up are warranted to provide more reliable evidence.

Role of growth hormone in hepatic and intestinal triglyceride-rich lipoprotein metabolism

BACKGROUND

Elevated plasma concentrations of hepatic- and intestinally-derived triglyceride-rich lipoproteins (TRL) are implicated in the pathogenesis of atherosclerotic cardiovascular disease and all-cause mortality. Excess of TRL is the driving cause of atherogenic dyslipidemia commonly occurring in insulin-resistant individuals such as patients with obesity, type 2 diabetes and metabolic syndrome. Interestingly, growth hormone (GH)-deficient individuals display similar atherogenic dyslipidemia, suggesting an important role of GH and GH deficiency in the regulation of TRL metabolism.

OBJECTIVE

We aimed to examine the direct and/or indirect role of GH on TRL metabolism.

METHODS

We investigated the effect on fasting and postprandial hepatic-TRL and intestinal-TRL metabolism of short-term (one month) withdrawal of GH in 10 GH-deficient adults.

RESULTS

After GH withdrawal, we found a reduction in fasting plasma TRL concentration (significant decrease in TRL-TG, TRL-cholesterol, TRL-apoB-100, TRL-apoC-III and TRL-apoC-II) but not in postprandial TRL response. This reduction was due to fewer fasting TRL particles without a change in TG per particle and was not accompanied by a change in postprandial TRL-apoB-48 response. Individual reductions in TRL correlated strongly with increases in insulin sensitivity and decreases in TRL-apoC-III.

CONCLUSION

In this relatively short term 'loss of function' human experimental model, we have shown an unanticipated reduction of hepatic-TRL particles despite increase in total body fat mass and reduction in lean mass. These findings contrast with the atherogenic dyslipidemia previously described in chronic GH deficient states, providing a new perspective for the role of GH in lipoprotein metabolism.

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.

Effects of bariatric surgery on lipid-lipoprotein profile

Most patients with severe obesity will present some lipid-lipoprotein abnormalities. The atherogenic dyslipidemia associated with severe obesity is characterized by elevated fasting and postprandial triglyceride levels, low high-density lipoprotein cholesterol concentrations, and increased proportion of small and dense low-density lipoproteins. Bariatric surgery has been proven safe and successful in terms of long-term weight loss and improvement in obesity co-existing metabolic conditions including lipid-lipoprotein abnormalities. Nevertheless, bariatric surgery procedures are not all equivalent. We conducted a comprehensive critical analysis of the literature related to severe obesity, bariatric surgery and lipid-lipoprotein metabolism/profile. In this review, we described the metabolic impacts of different bariatric surgery procedures on the lipid-lipoprotein profile, and the mechanisms linking bariatric surgery and dyslipidemia remission based on recent epidemiological, clinical and preclinical studies. Further mechanistic studies are essential to assess the potential of bariatric/metabolic surgery in the management of lipid-lipoprotein abnormalities associated with severe obesity. Understanding the beneficial effects of various bariatric surgery procedures on the lipid-lipoprotein metabolism and profile may result in a wider acceptance of this strategy as a long-term metabolic treatment of lipid-lipoprotein abnormalities in severe obesity and help clinician to develop an individualized and optimal approach in the management of dyslipidemia associated with severe obesity. BRIEF SUMMARY: Abnormal lipid-lipoprotein profile is frequent in patients with severe obesity. Significant improvements in lipid-lipoprotein profile following bariatric surgery occur early in the postoperative period, prior to weight loss, and persists throughout the follow-up. The mechanisms that facilitate the remission of dyslipidemia after bariatric surgery, may involve positive effects on adipose tissue distribution/function, insulin sensitivity, liver fat content/function and lipid-lipoprotein metabolism.

The dual glucose-dependent insulinotropic peptide and glucagon-like peptide-1 receptor agonist, tirzepatide, improves lipoprotein biomarkers associated with insulin resistance and cardiovascular risk in patients with type 2 diabetes

AIM

To better understand the marked decrease in serum triglycerides observed with tirzepatide in patients with type 2 diabetes, additional lipoprotein-related biomarkers were measured post hoc in available samples from the same study.

MATERIALS AND METHODS

Patients were randomized to receive once-weekly subcutaneous tirzepatide (1, 5, 10 or 15 mg), dulaglutide (1.5 mg) or placebo. Serum lipoprotein profile, apolipoprotein (apo) A-I, B and C-III and preheparin lipoprotein lipase (LPL) were measured at baseline and at 4, 12 and 26 weeks. Lipoprotein particle profile by nuclear magnetic resonance was assessed at baseline and 26 weeks. The lipoprotein insulin resistance (LPIR) score was calculated.

RESULTS

At 26 weeks, tirzepatide dose-dependently decreased apoB and apoC-III levels, and increased serum preheparin LPL compared with placebo. Tirzepatide 10 and 15 mg decreased large triglyceride-rich lipoprotein particles (TRLP), small low-density lipoprotein particles (LDLP) and LPIR score compared with both placebo and dulaglutide. Treatment with dulaglutide also reduced apoB and apoC-III levels but had no effect on either serum LPL or large TRLP, small LDLP and LPIR score. The number of total LDLP was also decreased with tirzepatide 10 and 15 mg compared with placebo. A greater reduction in apoC-III with tirzepatide was observed in patients with high compared with normal baseline triglycerides. At 26 weeks, change in apoC-III, but not body weight, was the best predictor of changes in triglycerides with tirzepatide, explaining up to 22.9% of their variability.

CONCLUSIONS

Tirzepatide treatment dose-dependently decreased levels of apoC-III and apoB and the number of large TRLP and small LDLP, suggesting a net improvement in atherogenic lipoprotein profile.

Circulating Apolipoprotein L1 is associated with insulin resistance-induced abnormal lipid metabolism

Circulating ApolipoproteinL1 (ApoL1) is a component of pre-β-high-density lipoprotein (HDL), however little is known about the relationship of ApoL1 with cardiometabolic factors. Considering previous studies reporting the correlation of ApoL1 to triglyceride, we have hypothesized that ApoL1 associates with insulin-related metabolism. The current study examined their associations in 126 non-diabetic subjects and 36 patients with type 2 diabetes (T2DM). Non-diabetic subjects demonstrated triglyceride (standardized coefficients [s.c.] = 0.204, p < 0.05), body mass index (s.c. =0.232, p < 0.05) and HDL cholesterol (s.c. = −0.203, p < 0.05) as independent determinant of ApoL1 levels, and the significant elevation of ApoL1 in metabolic syndrome. Lipoprotein fractionation analysis revealed the predominant distribution of ApoL1 in large HDL fraction, and the significant increase of ApoL1 in large LDL fraction in high ApoL1 samples with insulin resistance. In T2DM, ApoL1 was higher in T2DM with metabolic syndrome, however ApoL1 was lower with β cell dysfunction. Insulin significantly promotes ApoL1 synthesis and secretion in HepG2 cells. In conclusion, circulating ApoL1 may be associated with abnormal HDL metabolism in insulin resistant status. This may suggest a regulation of insulin signal on the ApoL1 level, leading to offer a novel insight to the ApoL1 biology.

Beneficial changes on plasma apolipoproteins A and B, high density lipoproteins and oxidized low density lipoproteins in obese women after bariatric surgery: comparison between gastric bypass and sleeve gastrectomy

Background

The beneficial effects in lipid profiles after obesity surgery might be associated with the decrease in cardiovascular risk. However, direct comparison between different surgical techniques has not been extensively performed.

Methods

In the present study we compare 20 obese women submitted to laparoscopic Roux en Y gastric bypass (RYGB) with 20 women submitted to sleeve gastrectomy (SG). Twenty control women matched for age and baseline cardiovascular risk were also included. Both patients and controls were followed up for 1 year after surgery or conventional treatment with diet and exercise, respectively. Lipid profiles were measured at baseline, 6 and 12 months later. Carotid intima-media thickness was measured by ultrasonography at baseline and at the end of the study.

Results

Women submitted to bariatric surgery showed a decrease in total cholesterol, triglycerides, oxidized-LDL and ApoB, and an increase in HDL and ApoA concentrations that occurred regardless of the surgical procedure. LDL concentrations, however, decreased only after RYGB whereas Lp(a) showed no changes. We did not observe any correlation between the changes in serum lipid concentrations and those in carotid intima-media thickness.

Conclusions

Sleeve gastrectomy and gastric bypass induce a similar beneficial effect on serum lipids in women with high cardiovascular risk 1 year after surgery.

Modulation of the gut microbiota by the mixture of fish oil and krill oil in high-fat diet-induced obesity mice

Previous studies confirmed that dietary supplements of fish oil and krill oil can alleviate obesity in mice, but the underlying mechanism remains unclear. This study aims to discern whether oil treatment change the structure of the gut microbiota during the obesity alleviation. The ICR mice received high-fat diet (HFD) continuously for 12 weeks after two weeks of acclimatization with a standard chow diet, and the mice fed with a standard chow diet were used as the control. In the groups that received HFD with oil supplementation, the weight gains were attenuated and the liver index, total cholesterol, triglyceride and low-density lipoprotein cholesterol were reduced stepwise compared with the HFD group, and the overall structure of the gut microbiota, which was modulated in the HFD group, was shifted toward the structure found in the control group. Moreover, eighty-two altered operational taxonomic units responsive to oil treatment were identified and nineteen of them differing in one or more parameters associated with obesity. In conclusion, this study confirmed the effect of oil treatment on obesity alleviation, as well as on the microbiota structure alterations. We proposed that further researches are needed to elucidate the causal relationship between obesity alleviation and gut microbiota modulation.