Effective lipid modification by partial ileal bypass reduced long-term coronary heart disease mortality and morbidity: five-year posttrial follow-up report from the POSCH. Program on the Surgical Control of the Hyperlipidemias

Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy improves lipid and glucose homeostasis in ob/ob mice

OBJECTIVE

The objective of this study was to compare the general and metabolic impact of single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) with Roux-en-Y gastric bypass (RYGB) in an obese (ob/ob) mouse model.

METHODS

10-week-old male ob/ob mice underwent either SADI-S, RYGB, or laparotomy surgery (Sham group). General and metabolic parameters were assessed during a 5-week period thereafter.

RESULTS

SADI-S induced a deeper weight loss ([mean ± SEM] -41.2% ± 3.3%) than RYGB (-5.6% ± 3.5%, p < 0.001) compared with the Sham group (+6.3% ± 1.0%, p < 0.05). A significant food restriction was observed after SADI-S only (-31%, 117.4 ± 10.3 g vs. 170.2 ± 5.2 g of food at day 35 in Sham group mice, p < 0.001). Random-fed glycemia and glucose tolerance were more improved after SADI-S than RYGB. SADI-S decreased plasma cholesterol concentration by 60% (0.49 ± 0.04 g/L vs. 1.40 ± 0.10 g/L in the Sham group at day 35, p < 0.01), significantly more than RYGB (1.04 ± 0.14 g/L, p = 0.018). Plasma sitosterol/cholesterol and campesterol/cholesterol ratios were decreased after SADI-S, suggesting a reduced intestinal cholesterol absorption. SADI-S increased exogenous plasma cholesterol-D7 clearance and fecal elimination, also indicating an increased plasma cholesterol excretion. Studying a pair-fed group demonstrated that calorie restriction alone did not explain the beneficial impact of SADI-S.

CONCLUSIONS

SADI-S is associated with a greater improvement in lipid and glucose homeostasis than RYGB in ob/ob mice.

Established and potential cardiovascular risk factors in metabolic syndrome: Effect of bariatric surgery

PURPOSE OF REVIEW

The aim of this review was to provide an overview of the role of novel biomarkers in metabolic syndrome, their association with cardiovascular risk and the impact of bariatric surgery on these biomarkers.

RECENT FINDINGS

Metabolic syndrome encompasses an intricate network of health problems, and its constituents extend beyond the components of its operational definition. Obesity-related dyslipidaemia not only leads to quantitative changes in lipoprotein concentration but also alteration in qualitative composition of various lipoprotein subfractions, including HDL particles, rendering them proatherogenic. This is compounded by the concurrent existence of obstructive sleep apnoea (OSA) and nonalcoholic fatty liver disease (NAFLD), which pave the common pathway to inflammation and oxidative stress culminating in heightened atherosclerotic cardiovascular disease (ASCVD) risk. Bariatric surgery is an exceptional modality to reverse both conventional and less recognised aspects of metabolic syndrome. It reduces the burden of atherosclerosis by ameliorating the impact of obesity and its related complications (OSA, NAFLD) on quantitative and qualitative composition of lipoproteins, ultimately improving endothelial function and cardiovascular morbidity and mortality.

SUMMARY

Several novel biomarkers, which are not traditionally considered as components of metabolic syndrome play a crucial role in determining ASCVD risk in metabolic syndrome. Due to their independent association with ASCVD, it is imperative that these are addressed. Bariatric surgery is a widely recognized intervention to improve the conventional risk factors associated with metabolic syndrome; however, it also serves as an effective treatment to optimize novel biomarkers.

Pharmacotherapy in familial hypercholesterolemia - Current state and emerging paradigms

Familial hypercholesterolemia is a highly prevalent but underdiagnosed disease marked by increased risk of cardiovascular morbidity and mortality. Aggressive reduction of LDL-cholesterol is a hallmark of cardiovascular risk mitigation in familial hypercholesterolemia. More recently, we have witnessed an expanded repertoire of pharmacologic agents that directly target LDL-cholesterol and/or reduce heart disease burden. In this state-of-the-art review, we explore the development, clinical efficacy and limitations of existing and potential future therapeutics in familial hypercholesterolemia.

Bariatric Surgery and the Risk of Cerebrovascular Events: a Meta-analysis of 17 Studies Including 3,124,063 Subjects

PURPOSE

To perform a meta-analysis of the literature to evaluate the prevalence of cerebrovascular comorbidities between patients undergoing bariatric surgery and those not undergoing bariatric surgery.

MATERIALS AND METHODS

Studies about the risk of cerebrovascular disease both before and after bariatric surgery were systematically explored in multiple electronic databases, including PubMed, Web of Science, Cochrane Library, and Embase, from the time of database construction to May 2022.

RESULTS

Seventeen studies with 3,124,063 patients were finally included in the meta-analysis. There was a statistically significant reduction in cerebrovascular event risk following bariatric surgery (OR 0.68; 95% CI 0.58 to 0.78; I² = 87.9%). The results of our meta-analysis showed that bariatric surgery was associated with decreased cerebrovascular event risk in the USA, Sweden, the UK, and Germany but not in China or Finland. There was no significant difference in the incidence of cerebrovascular events among bariatric surgery patients compared to non-surgical patients for greater than or equal to 5 years, but the incidence of cerebrovascular events less than 5 years after bariatric surgery was significantly lower in the surgical patients compared to non-surgical patients in the USA population.

CONCLUSION

Our meta-analysis suggested that bariatric surgery for severe obesity was associated with a reduced risk of cerebrovascular events in the USA, Sweden, the UK, and Germany. Bariatric surgery significantly reduced the risk of cerebrovascular events within 5 years, but there was no significant difference in the risk of cerebrovascular events for 5 or more years after bariatric surgery in the USA.

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.

Reaching LDL-C Targets in Patients with Moderate, High, and Very High Risk for Cardiovascular Disease After Bariatric Surgery According to Different Guidelines

BACKGROUND

Cardiovascular disease (CVD) is highly prevalent in obese patients and is the leading cause of death. High levels of plasma low-density lipoprotein cholesterol (LDL-C) are associated with higher coronary artery disease (CAD) risk. The aim of the study was to assess the impact of the Roux-en-Y gastric bypass on the achievement of the currently proposed cardiovascular prevention goals after 1 year.

PATIENTS AND METHODS

We performed a retrospective analysis from a prospectively built database of patients who underwent a primary Roux-en-Y gastric bypass (RYGB) from 2004 to 2018. Patients with intermediate, high, or very high risk for CVD according to the 2018 AHA/ACC or the 2019 ESC/EAS guidelines were selected. An analysis of clinical and biochemical variables in 1 year was performed. Logistic multivariate regressions were made to assess the impact of preoperative and weight loss parameters in the achievement of LDL-C goals.

RESULTS

From 1039 patients, 70 met the selection criteria and were included in the analysis of the 2018 AHA/ACC guidelines, and 75 in the 2019 ESC/EAS guidelines. Mean decrease in LDL-C levels was 21.1 ± 40.2 mg/dL 1 year after surgery, and 29/34 patients were off medications. The percentage of patients achieving LDL-C goals according to the 2018 AHA/ACC guidelines was 27.1%, whereas according to the 2019 ESC/EAS guidelines, the percentages was 9.3%. The %TWL was associated with achieving LDL-C goals according to the 2018 AHA/ACC at 1 year.

CONCLUSIONS

RYGB induces a significant weight loss and an improvement in LDL-C levels 1 year after surgery. The number of patients that reached the goals varies according to the guidelines used and ranged from 9.3 to 27.1%.

Metabolic (Bariatric and Nonbariatric) Surgery for Type 2 Diabetes: A Personal Perspective Review

: Metabolic surgery can cause amelioration, resolution, and possible cure of type 2 diabetes. Bariatric surgery is metabolic surgery. In the future, there will be metabolic surgery operations to treat type 2 diabetes that are not focused on weight loss. These procedures will rely on neurohormonal modulation related to the gut as well as outside the peritoneal cavity. Metabolic procedures are and will always be in flux as surgeons seek the safest and most effective operative modality; there is no enduring gold standard operation. Metabolic bariatric surgery for type 2 diabetes is more than part of the clinical armamentarium, it is an invitation to perform basic research and to achieve fundamental scientific knowledge.

Outcomes of patients with and without baseline lipid-lowering therapy undergoing revascularization for left main coronary artery disease: analysis from the EXCEL trial

OBJECTIVES

There is a paucity of data on the effect of baseline lipid-lowering therapy (LLT) in patients undergoing revascularization for left main (LM) coronary artery disease (CAD). We compared outcomes for patients with LMCAD randomized to percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) according to the presence of baseline LLT in the EXCEL trial.

PATIENTS AND METHODS

The EXCEL trial randomized 1905 patients with LMCAD and SYNTAX scores up to 32 to PCI with everolimus-eluting stents versus CABG. Patients were categorized according to whether they were medically treated with LLT at baseline, and their outcomes were examined using multivariable Cox proportional hazards regression. The primary endpoint was a composite of death, stroke, or myocardial infarction at 3 years.

RESULTS

Among 1901 patients with known baseline LLT status, 1331 (70.0%) were medically treated with LLT at baseline. There were no significant differences between the PCI and CABG groups in the 3-year rates of the primary endpoint in patients with versus without baseline LLT (Pinteraction=0.62). Among patients with baseline LLT, the 3-year rate of ischemia-driven revascularization was higher after PCI compared with CABG (13.7 vs. 5.3%; adjusted hazard ratio=2.97; 95% confidence interval: 1.95-4.55; P<0.0001), in contrast to patients without baseline LLT (9.8 vs. 12.1%; adjusted hazard ratio=0.79; 95% confidence interval: 0.47-1.33; P=0.39) (Pinteraction=0.0003).

CONCLUSION

In the EXCEL trial, 3-year major adverse event rates after PCI versus CABG for LMCAD were similar and consistent in patients with and without LLT at baseline; however, revascularization during follow-up was more common after PCI compared with CABG in patients with baseline LLT, but not in those without baseline LLT.

Familial Hypercholesterolemia: New Horizons for Diagnosis and Effective Management

Familial hypercholesterolemia (FH) is a common genetic cause of premature cardiovascular disease (CVD). The reported prevalence rates for both heterozygous FH (HeFH) and homozygous FH (HoFH) vary significantly, and this can be attributed, at least in part, to the variable diagnostic criteria used across different populations. Due to lack of consistent data, new global registries and unified guidelines are being formed, which are expected to advance current knowledge and improve the care of FH patients. This review presents a comprehensive overview of the pathophysiology, epidemiology, manifestations, and pharmacological treatment of FH, whilst summarizing the up-to-date relevant recommendations and guidelines. Ongoing research in FH seems promising and novel therapies are expected to be introduced in clinical practice in order to compliment or even substitute current treatment options, aiming for better lipid-lowering effects, fewer side effects, and improved clinical outcomes.

PCSK9 inhibitors in the current management of atherosclerosis

The history of proprotein convertase subtilisin/kexin type 9 (PCSK9) in medical science is fascinating and the evolution of knowledge of its function has resulted in new medications of major importance for the cardiovascular (CV) patient. PCSK9 functions as a negative control or feedback for the cell surface receptors for low-density lipoprotein including its component of cholesterol (LDL-C). The initial and key findings were that different abnormalities of PCSK9 can result in an increase or a decrease of LDL-C because of more or less suppression of cell surface receptors. These observations gave hints and awoke interest that it might be possible to prepare monoclonal antibodies to PCSK9 and decrease its activity, after which there should be more active LDL-C cell receptors. The rest is a fascinating story that currently has resulted in two PCSK9 inhibitors, alirocumab and evolocumab, which, on average, decrease LDL-C approximately 50%. Nevertheless, if there are no contraindications, statins remain the standard of prevention for the high-risk CV patient and this includes both secondary and primary prevention. The new inhibitors are for the patient that does not attain the desired target for LDL-C reduction while taking a maximum statin dose or who does not tolerate any statin dose whatsoever. Atherosclerosis can be considered a metabolic disease and the clinician needs to realize this and think more and more of CV prevention. These inhibitors can contribute to both the stabilization and regression of atherosclerotic plaques and thereby avoid or delay major adverse cardiac events. (United States).

Is There an Ideal Low-Density Lipoprotein Cholesterol Level? Confusion regarding Lipid Guidelines, Low-Density Lipoprotein Cholesterol Targets, and Medical Management

There are multiple guidelines for managing patients with high-risk cardiovascular disease, and unfortunately for the practicing clinician, these guidelines are quite variable. Some are fairly specific whereas others are not, resulting in a great deal of confusion regarding whether management of low-density lipoprotein cholesterol (LDL-C) should be tailored only, targeted only, or managed by a combination of both. In the management of cardiovascular disease, favorable cardiovascular outcomes can be obtained by simply lowering the LDL-C in the absence of any other medications. The advent of statins, the most potent LDL-C-lowering medication yet when developed, provided benefits augmented by the presence of multiple pleiotropic effects. Tailoring and/or targeting the decrease in LDL-C is also an issue of concern. Then, in 2016, the new proprotein convertase sutilisin-like/kexin type 9 (PCSK9) inhibitors appeared, providing a solution to patients with high-risk cardiovascular disease with statin intolerance and those who did not attain a desired LDL-C level while on a high-dose statin. These new PCSK9 inhibitors necessitate a determination of how low the LDL-C can and should go, most likely safely down to a beneficial level of 25 mg/dL for the highest-risk patient. These issues are documented and discussed with an attempt to help the reader make an informed risk management decision.

Prevention of Carotid Artery Atherosclerosis: What is the Evidence?

Carotid artery atherosclerosis (CAA) represents a significant form of atherosclerosis with stroke as a major consequence. Whether it is a unique form of atherosclerosis is not established. However, this is not of major clinical relevance as no specific preventive measures over and above the established ones for cardiovascular risk are well established. Major risk factors for CAA are elevated low-density lipoprotein cholesterol (LDL-C), diabetes mellitus, tobacco use, hypertension, and increased inflammation. Identification of CAA prior to a clinical event centers on imaging studies. Studies with magnetic resonance imaging result in the best definition of CAA plaque morphology. Medical measures that result in prevention are especially centered on statins (marked reduction of the LDL-C) and hypertension control. Nonprocedural therapeutic measures to avoid and delay complications involve antiplatelet medications. Benefits from other measures such as increasing high-density lipoprotein cholesterol and increased exercise appear desirable but require more clinical evidence. In conclusion, there are enough evidence-based medicine results to demand intensive medical preventive measures and not just relegate the patient with asymptomatic or symptomatic CAA to decision-making only involving the surgeon and interventionalist.

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.

Defining the Role of PCSK9 Inhibitors in the Treatment of Hyperlipidemia

Statins remain the mainstay of medical cardiovascular risk reduction because of their effectiveness in decreasing low-density lipoprotein cholesterol (LDL-C) as well as some other potentially beneficial effects. The latest US 2013 lipid guidelines essentially recommend only the prescription of a high-dose statin for the high-risk patient. However, both quite old and quite new outcomes evidence, such as reported for ezetimibe, emphasize that LDL-C lowering is, in and of itself, quite important for cardiovascular risk reduction. It appears that the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors represent a major new contribution to this effort, especially for patients with severe familial hypercholesterolemia, proven clinical cardiovascular disease, statin intolerance, or failure to attain an acceptably low LDL-C goal despite maximum available medical management. Very recent clinical trials have proven overwhelmingly the effectiveness and safety of PCSK9 inhibitors for lowering LDL-C. Both alirocumab and evolocumab have now been approved by the US FDA and there are some initial favorable outcomes data. This review is intended to summarize available evidence and emphasize the possible clinical role of these inhibitors following the approval of alirocumab and evolocumab. Understanding the negative receptor feedback of PCSK9 and the mechanism and beneficial effect of PCSK9 inhibitors for cardiovascular risk reduction is essential for the up-to-date practitioner of cardiovascular medicine. There is every reasonable hope for significant cardiovascular benefit from these new additions to our medical cardiovascular armamentarium.

National lipid association recommendations for patient-centered management of dyslipidemia: part 1--full report

The leadership of the National Lipid Association convened an Expert Panel to develop a consensus set of recommendations for patient-centered management of dyslipidemia in clinical medicine. An Executive Summary of those recommendations was previously published. This document provides support for the recommendations outlined in the Executive Summary. The major conclusions include (1) an elevated level of cholesterol carried by circulating apolipoprotein B-containing lipoproteins (non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol [LDL-C], termed atherogenic cholesterol) is a root cause of atherosclerosis, the key underlying process contributing to most clinical atherosclerotic cardiovascular disease (ASCVD) events; (2) reducing elevated levels of atherogenic cholesterol will lower ASCVD risk in proportion to the extent that atherogenic cholesterol is reduced. This benefit is presumed to result from atherogenic cholesterol lowering through multiple modalities, including lifestyle and drug therapies; (3) the intensity of risk-reduction therapy should generally be adjusted to the patient's absolute risk for an ASCVD event; (4) atherosclerosis is a process that often begins early in life and progresses for decades before resulting a clinical ASCVD event. Therefore, both intermediate-term and long-term or lifetime risk should be considered when assessing the potential benefits and hazards of risk-reduction therapies; (5) for patients in whom lipid-lowering drug therapy is indicated, statin treatment is the primary modality for reducing ASCVD risk; (6) nonlipid ASCVD risk factors should also be managed appropriately, particularly high blood pressure, cigarette smoking, and diabetes mellitus; and (7) the measurement and monitoring of atherogenic cholesterol levels remain an important part of a comprehensive ASCVD prevention strategy.

[Dyslipidaemia and vascular risk. A new evidence based review]

Dyslipidaemia is one of the major risk factors for ischaemic heart disease, the leading cause of death worldwide. Early detection and therapeutic intervention are key elements in the adequate prevention of cardiovascular disease. It is essential to have knowledge of the therapeutic arsenal available for their appropriate use in each of the clinical situations that might be presented in our patients. In the past 3 years, there has been a proliferation of multiple guidelines for the clinical management of patients with dyslipidaemia, with apparent contradictory messages regarding the achievement of the control objectives, which are confusing clinicians. This review aims to provide an updated overview of the situation as regards dyslipidaemia, based on the positioning of both European and American guidelines, through different risk situations and ending with the concept of atherogenic dyslipidaemia as a recognized cardiovascular risk factor.

Review of clinical practice guidelines for the management of LDL-related risk

Managing risk related to low-density lipoprotein (LDL) is vital in therapy for patients at risk for atherosclerotic cardiovascular disease (ASCVD) events given its important etiologic role in atherogenesis. Despite decades of research showing reduction of ASCVD risk with multiple approaches to lowering of LDL cholesterol, there continue to be significant gaps in care with inadequate numbers of patients receiving standard of care lipid-lowering therapy. Confusion regarding implementation of the multiple published clinical practice guidelines has been identified as one contributor to suboptimal management of LDL-related risk. This review summarizes the current guidelines for reduction of LDL-related cardiovascular risk provided by a number of major professional societies, which have broad applicability to diverse populations worldwide. Statements have varied in the process and methodology of development of recommendations, the grading system for level and strength of evidence, the inclusion or exclusion of expert opinion, the suggested ASCVD risk assessment tool, the lipoproteins recommended for risk assessment, and the lipoprotein targets of therapy. The similarities and differences among important guidelines in the United States and internationally are discussed, with recommendations for future strategies to improve consistency in approaches to LDL-related ASCVD risk and to reduce gaps in implementation of evidence-based therapies.

Elobixibat and its potential role in chronic idiopathic constipation

Chronic idiopathic constipation is highly prevalent among adults. Bile acids (BAs) and the enterohepatic BA circulation modulate colonic secretion and motility that affect transit. BAs in the colon have a dual action as osmotic and stimulant agents. Newer agents, such as elobixibat (A3309), an inhibitor of the ileal BA transporter, have the potential to improve significantly the management of chronic constipation, with minimal adverse effects. Elobixibat modulates the enterohepatic BA circulation, enhancing the delivery of BAs to the colon where they induce secretory and motor effects. Secondary effects of the inhibition of BA absorption are reduced activation of the farnesoid X receptor, decreased secretion of fibroblast growth factor-19 into the portal circulation, and increased BA synthesis. This review focuses on the role of BAs, the enterohepatic BA circulation, and an ileal BA transporter inhibitor (elobixibat) in chronic constipation.

Ileal effect on blood glucose, HbA1c, and GLP-1 in Goto-Kakizaki rats

BACKGROUND

There have been enumerable studies on the effects of glucagon-like peptide-1 (GLP-1) on satiety and pancreatic islet function, stimulating the advocacy of surgical transposition of the ileum (rich in GLP-1-generating L-cells) higher in the gastrointestinal tract for earlier stimulation. In the Goto-Kakizaki rat with naturally occurring type 2 diabetes, we studied the influence of ileal exclusion (IE) and ileal resection (IR) on blood glucose, hemoglobin A1c (HbA1c), and GLP-1.

METHODS

In six control (Ctrl), 10 IE, and 10 IR rats, over 12 weeks of follow-up, we determined blood glucose, HbA1c, and GLP-1.

RESULTS

Two animals in the IE and IR groups did not survive to week 13. Both operated groups weighed more than the Ctrl group at baseline and at 13 weeks; thus, IE and IR did not retard weight gain (p < 0.05). All three groups were equally hyperglycemic at week 13: 255 ± 10.2 Ctrl, 262 ± 11.0 IE, 292 ± 17.8 IR (mg/dl ± SEM). The three groups had statistically identical markedly elevated HbA1c percentages at week 13: 14.7 ± 28 Ctrl, 11.7 ± 3.4 IE, 13.8 ± 3.5 IR (% ± SEM). The end-study GLP-1 values (pM ± SEM) were 5 ± 0.9 Ctrl, 33 ± 8.9 IE, and 25 ± 6.7 IR. P values for intergroup differences were IE vs. Ctrl 0.02, IR vs. Ctrl 0.02, and IE vs. IR 0.59.

CONCLUSIONS

Neither IE nor IR resulted in a decrease in the mean GLP-1 level. On the contrary, the exclusion or resection of the L-cell rich ileum raised GLP-1 levels 5- to 6-fold. This increase in the GLP-1 was not associated with the mitigation of hyperglycemia or elevated HbA1c levels.

Problems and possible solutions for therapy with statins

Despite issues about the value of statins, benefit for high cardiovascular (CV) risk outweighs problems. However, the practitioner must be aware of concerns, be prepared to respond, and justify statin usage. Symptoms of statin-related myopathy are of more concern than stated by pharmaceutical companies. Occurrence of myopathy symptoms, estimated to be up to 10.4%, can decrease statin adherence of high CV risk patients. Dosage modification, or use of pitavastatin, may help the problematic patient. There are concerns that there may be little benefit of statins for primary prevention in women. However, evidence appears to support statin use in women at high CV risk, both in primary and secondary prevention. Abandoning low-density lipoprotein cholesterol (LDL-C) as a valid target is unwarranted; there is much evidence to support "lower is better." The practitioner must be aware of the complicated processes causing atherosclerosis and when to incorporate new approaches to disease management. Tailoring therapy for CV risk, when indicated, may contribute further to LDL-C reduction. Liver inflammation can occur with statins but is of minimal concern; frequently, statins alleviate the problem. Unless liver transaminases are over three times normal, a statin should be prescribed, if indicated. The net effect of statins on cognition appears to be zero-no harm, no benefit. Despite reports of improved cognition, statins should not be prescribed for this. With diabetes mellitus (DM), statins can increase incidence, but the CV benefit far outweighs any risk. Therefore, statins should be prescribed in DM to reduce CV risk. Statins are a major medical contribution when used appropriately.

Elobixibat for the treatment of constipation

INTRODUCTION

Elobixibat (formerly A3309) is a first-in-class ileal bile acid transporter (IBAT) inhibitor for treatment of chronic idiopathic constipation (CIC; syn functional constipation). CIC affects up to 25% of the general population; and up to a half are unsatisfied with current therapies. There is an unmet need for safe and effective drugs to treat CIC.

AREAS COVERED

The authors present: i) an overview of Phase II clinical trials of elobixibat in CIC, based on peer-reviewed literature and congress presentations and ii) an evaluation of the efficacy and mechanism of action of elobixibat in the treatment of CIC.

EXPERT OPINION

Elobixibat provides a novel approach to treat chronic constipation via IBAT inhibition with enhanced delivery of bile acids to the colon. Pharmacodynamic studies show that it accelerates colonic transit, increases stool frequency, loosens stool consistency and relieves constipation-related symptoms in CIC patients. These beneficial effects are maintained for a minimum of 8 consecutive weeks of treatment. With minimal absorption and low systemic bioavailability, elobixibat is generally well tolerated and may offer the added benefit of improving serum lipid profiles through bile acid depletion.

Assessment of low-density lipoprotein targets

The clinical importance of lowering of total cholesterol and low-density lipoprotein cholesterol (LDL-C) to decrease cardiovascular (CV) risk has been verified over many years starting with significant support in 1984 of the then previous lipid hypothesis. Significant support of this hypothesis began that year with publication of the Lipid Research Clinic study. Since then, multiple other studies including outcomes studies have established the value of LDL-C reduction in decreasing CV risk. In addition, multiple other factors such as inflammation, endothelial dysfunction, nitric oxide, antioxidant properties, and plaque stabilization appear important for modifying CV risk and possible favorable alterations by medications such as statins must be considered. Nevertheless, reduction of LDL-C has well-established value and is being accepted by clinicians as a major guideline for CV disease prevention. However, there are still problems with adherence by many clinicians to CV risk modification. Therefore, abandoning LDL-C reduction as a target, as has been advocated by some, appears premature and contraindicated. A strategy of LDL-C reduction in no way interferes with increased understanding of the complexities of atherosclerosis and new approaches to CV disease prevention as they become supported by outcomes studies.

A review of the rationale for additional therapeutic interventions to attain lower LDL-C when statin therapy is not enough

Statins alone are not always adequate therapy to achieve low-density lipoprotein (LDL) goals in many patients. Many options are available either alone or in combination with statins that makes it possible to reach recommended goals in a safe and tolerable fashion for most patients. Ezetimibe and bile acid sequestrants reduce cholesterol transport to the liver and can be used in combination. Niacin is very effective at lowering LDL, beyond its ability to raise high-density lipoprotein and shift LDL particle size to a less atherogenic type. When statins cannot be tolerated at all, red yeast rice can be used if proper formulations of the product are obtained. Nutrients can also be added to the diet, including plant stanols and sterols, soy protein, almonds, and fiber, either individually or all together as a portfolio diet. A clear understanding of how each of these strategies works is essential for effective results.

Effects of A3309, an ileal bile acid transporter inhibitor, on colonic transit and symptoms in females with functional constipation

OBJECTIVES

Delivery of bile acid (BA) to the colon stimulates propulsive motility and fluid secretion. The objective of this study was to examine gastrointestinal (GI) transit effects of A3309, a small molecule inhibitor of the ileal BA transporter, in patients with functional constipation (FC).

METHODS

In a double-blind, placebo-controlled study of 36 female FC patients randomized to placebo, 15 mg A3309, or 20 mg A3309 administered orally once daily for 14 consecutive days, we assessed GI and colonic transit, stool characteristics, symptoms of constipation, fasting serum C4 (7α-hydroxy-4-cholesten-3-one) (surrogate of BA synthesis and malabsorption), and fasting serum total and low-density lipoprotein (LDL) cholesterol (surrogates of inhibition of BA absorption). Following the intention-to-treat paradigm, we used analysis of covariance to assess the overall treatment effects and Dunnett's test for pairwise comparisons.

RESULTS

Overall colonic transit (geometric center at 24 h) was significantly accelerated with 20 mg A3309 compared with placebo (overall effect, P=0.059; A3309 15 mg, P=0.18; and A3309 20 mg, P=0.04). Colonic transit at 48 h was significantly accelerated with both A3309 dosages (overall effect, P<0.001; A3309 15 mg, P=0.002; and A3309 20 mg, P<0.001). Significantly looser stool consistency was noted with both A3309 dosages compared with placebo (P<0.005). Significant effects of A3309 on constipation rating, ease of stool passage, and reduction of straining were also detected. The most common side effect was lower abdominal cramping/pain. A3309 treatment significantly and reversibly increased fasting C4 (A3309 15 mg, P=0.05; A3309 20 mg, P<0.01) but did not affect fasting total and LDL cholesterol.

CONCLUSIONS

A3309 accelerates colonic transit and loosens stool consistency in FC patients.

Effect of bariatric surgery on cardiovascular risk profile

Obesity is associated with increased risk for cardiovascular (CV) disease (CVD) and CV mortality. Bariatric surgery has been shown to resolve or improve CVD risk factors, to varying degrees. The objective of this systematic review was to determine the impact of bariatric surgery on CV risk factors and mortality. A systematic review of the published research was performed to evaluate evidence regarding CV outcomes in morbidly obese bariatric patients. Two major databases (PubMed and the Cochrane Library) were searched. The review included all original reports reporting outcomes after bariatric surgery, published in English, from January 1950 to July 2010. In total, 637 studies were identified from the initial screen. After applying inclusion and exclusion criteria, 52 studies involving 16,867 patients were included (mean age 42 years, 78% women). The baseline prevalence of hypertension, diabetes, and dyslipidemia was 49%, 28%, and 46%, respectively. Mean follow-up was 34 months (range 3 to 155), and the average excess weight loss was 52% (range 16% to 87%). Most studies reported significant decreases postoperatively in the prevalence of CV risk factors, including hypertension, diabetes, and dyslipidemia. Mean systolic pressure reduced from to 139 to 124 mm Hg and diastolic pressure from 87 to 77 mm Hg. C-reactive protein decreased, endothelial function improved, and a 40% relative risk reduction for 10-year coronary heart disease risk was observed, as determined by the Framingham risk score. In conclusion, this review highlights the benefits of bariatric surgery in reducing or eliminating risk factors for CVD. It provides further evidence to support surgical treatment of obesity to achieve CVD risk reduction.

Metabolic surgery: an evolution through bariatric animal models

Metabolic surgery was developed through the application and experience gained from bariatric or weight loss procedures. Much of our knowledge from the procedures comes from the study of animal models, where they have revealed anatomic feasibility, systemic physiological elements and cellular metabolic effects. The first generation of operation included the jejunoileal bypass and partial ileal bypass that led to the development of the current procedures including Roux-en-Y gastric bypass, biliopancreatic diversion, adjustable gastric banding and sleeve gastrectomy. These operations carry significant metabolic benefits and can reduce the risk of diabetes, heart disease and cancer. Further insights from these animal models can reveal genetic, molecular and systemic effects that can enhance and develop the next generation of metabolic operations.

Chenodeoxycholate in females with irritable bowel syndrome-constipation: a pharmacodynamic and pharmacogenetic analysis

BACKGROUND & AIMS

Sodium chenodeoxycholate (CDC) accelerates colonic transit in health. Our aim was to examine pharmacodynamics (colonic transit, bowel function) and pharmacogenetics of CDC in constipation-predominant irritable bowel syndrome (IBS-C).

METHODS

In a double-blind placebo-controlled study, 36 female patients with IBS-C were randomized to treatment with delayed-release oral formulations of placebo, 500 mg CDC, or 1000 mg CDC for 4 days. We assessed gastrointestinal and colonic transit, stool characteristics, and associations of transit with fasting serum 7αC4 (surrogate of bile acid synthesis) and FGF19 (negative regulator of bile acid synthesis) levels. Candidate genetic polymorphisms involved in regulation of bile acid synthesis were analyzed in the 36 patients with IBS-C and 57 healthy volunteers to assess genetic influence on effects of CDC on transit.

RESULTS

Overall colonic transit and ascending colon emptying (AC t(½)) were significantly accelerated in the CDC group compared with placebo (P = .005 and P = .028, respectively). Looser stool consistency (P = .003), increased stool frequency (P = .018), and greater ease of passage (P = .024) were noted with CDC compared with placebo. The most common side effect was lower abdominal cramping/pain (P = .01). Fasting serum 7αC4 (but not FGF19) was positively associated with colonic transit (r(s) = 0.749, P = .003, placebo group). Genetic variation in FGFR4 was associated with AC t(½) in response to CDC (uncorrected P = .015); αKlothoβ variant showed a gene-by-treatment interaction based on patient subgroup (uncorrected P = .0088).

CONCLUSIONS

CDC accelerates colonic transit and improves bowel function in female patients with IBS-C. The rate of bile acid synthesis influences colonic transit. Genetic variation in negative feedback inhibition of bile acid synthesis may affect CDC-mediated acceleration of colonic transit.

Metabolic, renal, and nutritional consequences of bariatric surgery: implications for the clinician

Management of obesity-associated comorbidities costs about $60 billion/year, about 5% of total US healthcare expenditure. Bariatric surgery is the only proven effective weight loss therapy for severely obese patients with a BMI > or =35 kg/m2. Bariatric surgery produces long-term weight loss, improves quality of life, and reduces the number of sick days and medication costs. Surgery has a profound effect on the metabolic milieu and nutritional status from the first few days after surgery, even before significant weight loss has been achieved. Metabolic effects of bariatric surgery reduce obesity-related comorbidities like type 2 diabetes, hypertension, metabolic syndrome, and cardiovascular disease risk. Improvement in renal function is seen, but adverse effects like oxalate nephropathy can lead to chronic kidney disease or end-stage renal disease (CKD/ESRD). Surgery can also lead to micronutrient deficiencies, making dietary supplementation necessary. Reduction in insulin resistance and hypertension after surgery makes medication adjustment imperative. Improvement in comorbidities and nutritional deficiencies after bariatric surgery has important clinical implications.

Overall mortality, incremental life expectancy, and cause of death at 25 years in the program on the surgical control of the hyperlipidemias

OBJECTIVE

To present the longest follow-up report of any lipid-atherosclerosis intervention trial.

SUMMARY OF BACKGROUND DATA

The Program on the Surgical Control of the Hyperlipidemias (POSCH), a secondary, clinical/arteriographic, randomized controlled trial, was the first lipid-atherosclerosis trial to demonstrate unequivocally that low density lipoprotein cholesterol reduction reduced the incidence of coronary heart disease death and myocardial infarction.

METHODS

We report POSCH 25 years follow-up for overall mortality, specific cause of death, and certain subgroup analyses, as well as a prediction for increase in life expectancy derived from the POSCH database, supplemented by the 2006 National Death Index, 1989-2006.

RESULTS

There were 838 patients randomized in POSCH (421 surgery, 417 control). At 25 years follow-up, the difference in the restricted mean survival and the logrank (Mantel-Haenszel) statistic was statistically significant, with survival probabilities of 0.57 (surgery) and 0.51 (controls). Cause of death data indicated a significant increase in cardiovascular deaths in the control group; cancer deaths were also greater in the control group but this was not significant. The most compelling subgroup analysis was a significant increase in survival, starting at 5 years after randomization, in the surgery group for patients with an ejection fraction > or = 50%, with relative probabilities of 0.61 (surgery) and 0.51 (control). The estimated incremental increase in life expectancy over more than 25 years of follow-up was 1.0 year overall and 1.7 years in the cohort with an ejection fraction > or = 50%.

CONCLUSIONS

A 25-year mortality follow-up in POSCH shows statistically significant gains in overall survival, cardiovascular disease-free survival, and life expectancy in the surgery group compared with the control group.

Bile acids: short and long term effects in the intestine

Bile acids have secretory, motility and antimicrobial effects in the intestine. In patients with bile acid malabsorption the amount of primary bile acids in the colon is increased compared to healthy controls. Deoxycholic acid is affecting the intestinal smooth muscle activity. Chenodeoxycholic acid has the highest potency to affect intestinal secretion. Litocholic acid has little effect in the lumen of intestine compared to both deoxycholic acid and chenodeoxycholic acid. There is no firm evidence that clinically relevant concentrations of bile acids induce colon cancer. Alterations in bile acid metabolism may be involved in the pathophysiology of constipation.

One year improvements in cardiovascular risk factors: a comparative trial of laparoscopic Roux-en-Y gastric bypass vs. adjustable gastric banding

BACKGROUND

Coronary artery disease (CAD) is the leading cause of death in the industrialized world with obesity as a leading preventable risk factor. Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) have been shown to improve certain biochemical cardiovascular risk factors (BCRFs) at 1 year post-op, however no study has directly compared the 12-month BCRF improvements of RYGB vs. LAGB.

METHODS

At a single academic institution (2004-2009), we measured BCRF in 838 consecutive bariatric patients (765 RYGB, 73 LAGB) pre-operatively and at 12 months post-operatively. BCRF included total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides (Trig), Trig/HDL ratio, lipoprotein(a) (Lp(a)), homocysteine (HmC), high sensitivity C-reactive protein (hs-CRP), fasting insulin (FI), and hemoglobin A1C (Hgb A1C). Pre-op and 12-month post-op values were compared by a paired t test of equal variance.

RESULTS

At 12 months post-op, RYGB patients had lost 77% of their excess weight and had significant improvements in TC, LDL, HDL, Trig, Trig/HDL, HmC, hs-CRP, FI, and Hgb A1C. LAGB patients lost 47.6% of their excess weight and had significant improvements in Trig, Trig/HDL, HmC, hs-CRP, and Hgb A1C. Having RYGB instead of LAGB was predictive of significantly greater improvements in TC at 12 months post-operatively.

CONCLUSIONS

In this study, both RYGB and LAGB demonstrated significant weight loss and improvements in BCRF at 12 months post-op. RYGB produced significant improvements in a greater number of BCRFs and in some instances the 12-month post-op BCRF values were significantly lower risk in RYGB vs. LAGB patients.

Effects of chenodeoxycholate and a bile acid sequestrant, colesevelam, on intestinal transit and bowel function

BACKGROUND & AIMS

Di-alpha hydroxy bile salt, sodium chenodeoxycholate (CDC), and bile acid binding have unclear effects on colonic transit in health and disease.

METHODS

We performed 2 randomized, double-blind, placebo-controlled studies. In healthy volunteers (20 per group), we evaluated the effects of oral placebo, 500 mg, or 1000 mg of CDC (delayed-release, each given for 4 days) on gastrointestinal and colonic transit. A second trial compared the effects of colesevelam (1.875 g, twice daily) versus placebo in 24 patients (12 per group) with diarrhea-predominant irritable bowel syndrome (IBS-D) on transit, daily bowel frequency and consistency, and colonic mucosal permeability. Serum fasting 7alpha-hydroxy-4-cholesten-3-one (7alphaC4) was measured to screen for bile acid malabsorption. Effects of treatments on transit were compared using analysis of covariance with body mass index and 7alphaC4 as covariates.

RESULTS

In healthy volunteers, CDC significantly accelerated colonic transit (at 24 and 48 hours, P = .01 and P < .0001, respectively), increased stool frequency and ease of passage (both P < .001), and evacuation (P = .02), and decreased stool consistency (P < .001). Four of the 24 IBS-D patients had increased serum 7alphaC4 levels. In IBS-D, colesevelam modestly affected overall colonic transit (24 h; P = .22). Emptying of the ascending colon took an average of 4 hours longer in patients given colesevelam compared with placebo; treatment effect was associated with baseline serum 7alphaC4 levels (P = .0025). Colesevelam was associated with greater ease of stool passage (P = .048) and somewhat firmer stool consistency (P = .12). No effects on mucosal permeability or safety were identified.

CONCLUSIONS

Sodium chenodeoxycholate in health and colesevelam in IBS-D patients have opposite effects on colonic transit and fecal parameters.

Increased apoB/apoA-I Ratio is Predictive of Peripheral Arterial Disease in Initially Healthy 58-Year-old Men during 8.9 Years of Follow-up

The aim of the present study was to investigate, if increased levels of apoB/apoA-I ratios are associated with future peripheral arterial disease as measured by ankle-brachial index. Increased apoB/apoA-I levels are defined as 0.9, which has been suggested for men, and as 0.63, which has observed to be associated with plaques in the femoral artery. The study was performed in a cohort of initially clinically healthy 58-year-old men living in the city of Göteborg, Sweden. The group with an apoB/apoA-I ratio ≥0.9 had a significantly increased risk of having PAD during 8.9 years of follow-up than the group below that level (OR: 2.15 CI: 1.21 to 3.82, p < 0.01). When applying the lower apoB/apoA-I cut off, results showed that the group with a level >0.63 had more than a three-fold risk of future PAD compared to the group ≤0.63 (OR: 3.28 CI: 1.14 to 9.40, p < 0.05).

Simvastatin with or without ezetimibe in familial hypercholesterolemia

BACKGROUND

Ezetimibe, a cholesterol-absorption inhibitor, reduces levels of low-density lipoprotein (LDL) cholesterol when added to statin treatment. However, the effect of ezetimibe on the progression of atherosclerosis remains unknown.

METHODS

We conducted a double-blind, randomized, 24-month trial comparing the effects of daily therapy with 80 mg of simvastatin either with placebo or with 10 mg of ezetimibe in 720 patients with familial hypercholesterolemia. Patients underwent B-mode ultrasonography to assess the intima-media thickness of the walls of the carotid and femoral arteries. The primary outcome measure was the change in the mean carotid-artery intima-media thickness, which was defined as the average of the means of the far-wall intima-media thickness of the right and left common carotid arteries, carotid bulbs, and internal carotid arteries.

RESULTS

The primary outcome, the mean (+/-SE) change in the carotid-artery intima-media thickness, was 0.0058+/-0.0037 mm in the simvastatin-only group and 0.0111+/-0.0038 mm in the simvastatin-plus-ezetimibe (combined-therapy) group (P=0.29). Secondary outcomes (consisting of other variables regarding the intima-media thickness of the carotid and femoral arteries) did not differ significantly between the two groups. At the end of the study, the mean (+/-SD) LDL cholesterol level was 192.7+/-60.3 mg per deciliter (4.98+/-1.56 mmol per liter) in the simvastatin group and 141.3+/-52.6 mg per deciliter (3.65+/-1.36 mmol per liter) in the combined-therapy group (a between-group difference of 16.5%, P<0.01). The differences between the two groups in reductions in levels of triglycerides and C-reactive protein were 6.6% and 25.7%, respectively, with greater reductions in the combined-therapy group (P<0.01 for both comparisons). Side-effect and safety profiles were similar in the two groups.

CONCLUSIONS

In patients with familial hypercholesterolemia, combined therapy with ezetimibe and simvastatin did not result in a significant difference in changes in intima-media thickness, as compared with simvastatin alone, despite decreases in levels of LDL cholesterol and C-reactive protein. (ClinicalTrials.gov number, NCT00552097 [ClinicalTrials.gov].).