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Concept: Low-density lipoprotein

1306

Background Observational cohort studies and a secondary prevention trial have shown an inverse association between adherence to the Mediterranean diet and cardiovascular risk. We conducted a randomized trial of this diet pattern for the primary prevention of cardiovascular events. Methods In a multicenter trial in Spain, we randomly assigned participants who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was the rate of major cardiovascular events (myocardial infarction, stroke, or death from cardiovascular causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years. Results A total of 7447 persons were enrolled (age range, 55 to 80 years); 57% were women. The two Mediterranean-diet groups had good adherence to the intervention, according to self-reported intake and biomarker analyses. A primary end-point event occurred in 288 participants. The multivariable-adjusted hazard ratios were 0.70 (95% confidence interval [CI], 0.54 to 0.92) and 0.72 (95% CI, 0.54 to 0.96) for the group assigned to a Mediterranean diet with extra-virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively, versus the control group (109 events). No diet-related adverse effects were reported. Conclusions Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events. (Funded by the Spanish government’s Instituto de Salud Carlos III and others; Controlled-Trials.com number, ISRCTN35739639 .).

Concepts: Myocardial infarction, Atherosclerosis, Cardiovascular disease, Low-density lipoprotein, Fat, Olive oil, Greece, Mediterranean diet

443

It is well known that total cholesterol becomes less of a risk factor or not at all for all-cause and cardiovascular (CV) mortality with increasing age, but as little is known as to whether low-density lipoprotein cholesterol (LDL-C), one component of total cholesterol, is associated with mortality in the elderly, we decided to investigate this issue.

Concepts: Cholesterol, Atherosclerosis, Cardiovascular disease, Low-density lipoprotein, Atheroma, Niacin

437

Background Evolocumab is a monoclonal antibody that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9) and lowers low-density lipoprotein (LDL) cholesterol levels by approximately 60%. Whether it prevents cardiovascular events is uncertain. Methods We conducted a randomized, double-blind, placebo-controlled trial involving 27,564 patients with atherosclerotic cardiovascular disease and LDL cholesterol levels of 70 mg per deciliter (1.8 mmol per liter) or higher who were receiving statin therapy. Patients were randomly assigned to receive evolocumab (either 140 mg every 2 weeks or 420 mg monthly) or matching placebo as subcutaneous injections. The primary efficacy end point was the composite of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization. The key secondary efficacy end point was the composite of cardiovascular death, myocardial infarction, or stroke. The median duration of follow-up was 2.2 years. Results At 48 weeks, the least-squares mean percentage reduction in LDL cholesterol levels with evolocumab, as compared with placebo, was 59%, from a median baseline value of 92 mg per deciliter (2.4 mmol per liter) to 30 mg per deciliter (0.78 mmol per liter) (P<0.001). Relative to placebo, evolocumab treatment significantly reduced the risk of the primary end point (1344 patients [9.8%] vs. 1563 patients [11.3%]; hazard ratio, 0.85; 95% confidence interval [CI], 0.79 to 0.92; P<0.001) and the key secondary end point (816 [5.9%] vs. 1013 [7.4%]; hazard ratio, 0.80; 95% CI, 0.73 to 0.88; P<0.001). The results were consistent across key subgroups, including the subgroup of patients in the lowest quartile for baseline LDL cholesterol levels (median, 74 mg per deciliter [1.9 mmol per liter]). There was no significant difference between the study groups with regard to adverse events (including new-onset diabetes and neurocognitive events), with the exception of injection-site reactions, which were more common with evolocumab (2.1% vs. 1.6%). Conclusions In our trial, inhibition of PCSK9 with evolocumab on a background of statin therapy lowered LDL cholesterol levels to a median of 30 mg per deciliter (0.78 mmol per liter) and reduced the risk of cardiovascular events. These findings show that patients with atherosclerotic cardiovascular disease benefit from lowering of LDL cholesterol levels below current targets. (Funded by Amgen; FOURIER ClinicalTrials.gov number, NCT01764633 .).

Concepts: Cholesterol, Myocardial infarction, Atherosclerosis, Cardiovascular disease, Low-density lipoprotein, Statin, Atheroma, Apolipoprotein B

291

Elevated levels of blood cholesterol are associated with cardiovascular disease, a leading cause of morbidity and mortality worldwide. Current therapies for addressing elevated blood cholesterol can be inadequate, ineffective or associated with side effects; therefore, the search for additional therapies is ongoing. This study evaluated Daily Body Restore (DBR), a proprietary blend of 9 probiotic organisms of the genera Lactobacillus and Bifidobacterium, and 10 digestive enzymes, for its effects on cholesterol metabolism using an in vitro system and a mouse model.

Concepts: Cell, Bacteria, Metabolism, Nutrition, Atherosclerosis, Low-density lipoprotein, Steroid, Hypercholesterolemia

273

Statins reduce LDL cholesterol and prevent vascular events, but their net effects in people at low risk of vascular events remain uncertain.

Concepts: Cholesterol, Myocardial infarction, Atherosclerosis, Low-density lipoprotein, Statin, Mevalonate pathway

230

The accuracy of the 2013 American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort Risk Equation for atherosclerotic cardiovascular disease (ASCVD) events in contemporary and ethnically diverse populations is not well understood.

Concepts: Myocardial infarction, Atherosclerosis, Demography, Blood vessel, Cardiovascular disease, Low-density lipoprotein, Cardiovascular diseases, Lipoprotein(a)

188

Abstract Objective. This study aimed to investigate the association of lipoprotein and triglyceride levels with all-cause mortality in a population free from diabetes and cardiovascular disease (CVD) at baseline. The European Guidelines on cardiovascular disease prevention state that in general total cholesterol (TC) should be < 5 mmol/L (190 mg/dL) and low-density lipoprotein cholesterol (LDL-C) should be < 3 mmol/L (115 mg/dL). Design. A population-based register study in the period 1999-2007 including 118 160 subjects aged 50 + without statin use at baseline. All-cause mortality was related to lipoprotein and triglyceride levels and adjusted for statin use after inclusion. Results. All-cause mortality was lower in the groups with TC or LDL-C above the recommended levels. Compared with subjects with TC < 5 mmol/L, adjusted hazard ratios for the group aged 60-70 years ranged from 0.68 (95% confidence interval (CI) 0.61-0.77) for TC 5-5.99 mmol/L to 0.67 (95% CI 0.59-0.75) for TC 6-7.99 mmol/L and 1.02 (95% CI 0.68-1.53) for TC ≥ 8 mmol/L in males and from 0.57 (95% CI 0.48-0.67) to 0.59 (95% CI 0.50-0.68) and 1.02 (95% CI: 0.77-1.37) in females. For triglycerides, ratios compared with the group < 1 mmol/L in the females aged 60-70 years ranged from 1.04 (95% CI 0.88-1.23) to 1.35 (95% CI 1.10-1.66) and 1.25 (95% CI 1.05-1.48) for triglycerides 1-1.39 mmol/L, 1.4-1.69 mmol/L, and ≥ 1.7 mmol/L, respectively. Statin treatment after inclusion provided a survival benefit. Conclusion. These associations indicate that high lipoprotein levels do not seem to be definitely harmful in the general population. However, high triglyceride levels in females are associated with decreased survival.

Concepts: Cholesterol, Myocardial infarction, Atherosclerosis, Cardiovascular disease, Low-density lipoprotein, Statin, Atheroma, Triglyceride

182

Hypercholesterolemia plays a critical role in atherosclerosis. CD34+ CD45dim Lineage- hematopoietic stem/progenitor cells (HSPCs) give rise to the inflammatory cells linked to atherosclerosis. In mice, high cholesterol levels mobilize HSPCs into the bloodstream, and promote their differentiation to granulocytes and monocytes. The objective of our study was to determine how cholesterol levels affect HSPC quantity in humans.

Concepts: Cholesterol, Inflammation, Myocardial infarction, Atherosclerosis, Familial hypercholesterolemia, Low-density lipoprotein, Atheroma, Hypercholesterolemia

177

Despite a considerable amount of data available on the relationship between dietary glycemic index (GI) or load (GL) and cardiovascular disease (CVD) risk factors, in aggregate, the area remains unsettled. The aim of the present review was to summarize the effect of diets differing in GI/GL on CVD risk factors, by examining randomized controlled-feeding trials that provided all food and beverages to adult participants. The studies included a low and high GI/GL diet phase for a minimum of four weeks duration, and reported at least one outcome related to CVD risk; glucose homeostasis, lipid profile or inflammatory status. Ten publications representing five trials were identified. The low GI/GL compared to the high GI/GL diet unexpectedly resulted in significantly higher fasting glucose concentrations in two of the trials, and a lower area under the curve for glucose and insulin in one of the two studies during an oral glucose tolerance test. Response of plasma total, low density lipoprotein and high density lipoprotein cholesterol concentrations was conflicting in two of the studies for which data were available. There was either weak or no effect on inflammatory markers. The results of the five randomized controlled trials satisfying the inclusion criteria suggest inconsistent effects of the GI/GL value of the diet on CVD risk factors.

Concepts: Nutrition, Atherosclerosis, Diabetes mellitus, Cardiovascular disease, Low-density lipoprotein, Blood sugar, Insulin resistance, Glycemic index

171

BACKGROUND: Global demographic changes have stimulated marked interest in the process of ageing. There has been, and will continue to be, an unrelenting rise in the number of the oldest old ( >85 years of age). Together with an ageing population there comes an increase in the prevalence of age related disease. Of the diseases of ageing, cardiovascular disease (CVD) has by far the highest prevalence. It is regarded that a finely tuned lipid profile may help to prevent CVD as there is a long established relationship between alterations to lipid metabolism and CVD risk. In fact elevated plasma cholesterol, particularly Low Density Lipoprotein Cholesterol (LDL-C) has consistently stood out as a risk factor for having a cardiovascular event. Moreover it is widely acknowledged that LDL-C may rise with age in both sexes in a wide variety of groups. The aim of this work was to use a whole-body mathematical model to investigate why LDL-C rises with age, and to test the hypothesis that mechanistic changes to cholesterol absorption and LDL-C removal from the plasma are responsible for the rise. The whole-body mechanistic nature of the model differs from previous models of cholesterol metabolism which have either focused on intracellular cholesterol homeostasis or have concentrated on an isolated area of lipoprotein dynamics. The model integrates both current and previously published data relating to molecular biology, physiology, ageing and nutrition in an integrated fashion. RESULTS: The model was used to test the hypothesis that alterations to the rate of cholesterol absorption and changes to the rate of removal of LDL-C from the plasma are integral to understanding why LDL-C rises with age. The model demonstrates that increasing the rate of intestinal cholesterol absorption from 50% to 80% by age 65 years can result in an increase of LDL-C by as much as 34mg/dL in a hypothetical male subject. The model also shows that decreasing the rate of hepatic clearance of LDL-C gradually to 50% by age 65 years can result in an increase of LDL-C by as much as 116mg/dL. CONCLUSIONS: Our model clearly demonstrates that of the two putative mechanisms that have been implicated in the dysregulation of cholesterol metabolism with age, alterations to the removal rate of plasma LDL-C has the most significant impact on cholesterol metabolism and small changes to the number of hepatic LDL receptors can result in a significant rise in LDL-C. This first whole-body systems based model of cholesterol balance could potentially be used as a tool to further improve our understanding of whole-body cholesterol metabolism and its dysregulation with age. Furthermore, given further fine tuning the model may help to investigate potential dietary and lifestyle regimes that have the potential to mitigate the effects aging has on cholesterol metabolism.

Concepts: Cholesterol, Nutrition, Atherosclerosis, Cardiovascular disease, Low-density lipoprotein, Atheroma, Niacin, High-density lipoprotein