Assessing possible hazards of reducing serum cholesterol

Evaluation of Naples Score for Long-Term Mortality in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

The Naples score (NS), which is a composite of cardiovascular adverse event predictors including neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, albumin, and total cholesterol, has emerged as a prognostic risk score in cancer patients. We aimed to investigate the predictive value of NS for long-term mortality in ST-segment elevation myocardial infarction patients (STEMI). A total of 1889 STEMI patients were enrolled in this study. The median duration of the study was 43 months (IQR: 32-78). Patients were divided into 2 groups according to NS as group 1 and group 2. We created 3 models as a baseline model, model 1 (baseline + NS in continuous), and model 2 (baseline + NS as categorical). Group 2 patients had higher long-term mortality rates than group 1 patients. The NS was independently associated with long-term mortality and adding NS to a baseline model improved the model performance for prediction and discrimination of long-term mortality. Decision curve analysis demonstrated that model 1 had a better net benefit probability for detecting mortality compared with the baseline model. NS had the highest contributive significant effect in the prediction model. An easily accessible and calculable NS might be used for risk stratification of long-term mortality in STEMI patients undergoing primary percutaneous coronary intervention.

Effect of Gut Microbiota on Blood Cholesterol: A Review on Mechanisms

The gut microbiota serves as a pivotal mediator between diet and human health. Emerging evidence has shown that the gut microbiota may play an important role in cholesterol metabolism. In this review, we delve into five possible mechanisms by which the gut microbiota may influence cholesterol metabolism: (1) the gut microbiota changes the ratio of free bile acids to conjugated bile acids, with the former being eliminated into feces and the latter being reabsorbed back into the liver; (2) the gut microbiota can ferment dietary fiber to produce short-chain fatty acids (SCFAs) which are absorbed and reach the liver where SCFAs inhibit cholesterol synthesis; (3) the gut microbiota can regulate the expression of some genes related to cholesterol metabolism through their metabolites; (4) the gut microbiota can convert cholesterol to coprostanol, with the latter having a very low absorption rate; and (5) the gut microbiota could reduce blood cholesterol by inhibiting the production of lipopolysaccharides (LPS), which increases cholesterol synthesis and raises blood cholesterol. In addition, this review will explore the natural constituents in foods with potential roles in cholesterol regulation, mainly through their interactions with the gut microbiota. These include polysaccharides, polyphenolic entities, polyunsaturated fatty acids, phytosterols, and dicaffeoylquinic acid. These findings will provide a scientific foundation for targeting hypercholesterolemia and cardiovascular diseases through the modulation of the gut microbiota.

Relationship between Hyperlipidemia, Cardiovascular Disease and Stroke: A Systematic Review

BACKGROUND

Globally, dyslipidemia has been shown to be an independent predictor of many cardiovascular and cerebrovascular events, which led to recent advocacy towards dyslipidemia prevention and control as a key risk factor and its prognostic significance to reduce the burden of stroke and myocardial infarction (MI).

AIMS

This study aimed to evaluate hyperlipidemia as a risk factor connected with stroke and CVD. Moreover, having identified this risk factor, the study evaluates how hyperlipidemia has been examined earlier and what can be done in the future.

METHODS

All prospective studies concerning hyperlipidemia as risk factors for stroke and CVD were identified by a search of PubMed/MEDLINE and EMBASE databases with keywords hyperlipidemia, risk factors, stroke, and cardiovascular disease.

RESULTS

The constant positive association between the incidence of coronary heart disease and cholesterol concentration of LDL is apparent in observational studies in different populations. Thus, the reduction of LDL cholesterol in those populations, particularly with regard to initial cholesterol concentrations, can reduce the risk of vascular diseases. However, the impact of using lipid-lowering drugs, such as statins, has been demonstrated in several studies as an important factor in decreasing the mortality and morbidity rates of patients with stroke and CVD.

CONCLUSION

After reviewing all the research mentioned in this review, most studies confirmed that hyperlipidemia is a risk factor for stroke and correlated in patients with CVD.

PCSK9 and cancer: Rethinking the link

BACKGROUND

Cancer is emerging as a major problem globally, as it accounts for the second cause of death despite medical advances. According to epidemiological and basic studies, cholesterol is involved in cancer progression and there are abnormalities in cholesterol metabolism of cancer cells including prostate, breast, and colorectal carcinomas. However, the importance of cholesterol in carcinogenesis and thereby the role of cholesterol homeostasis as a therapeutic target is still a debated area in cancer therapy. Proprotein convertase subtilisin/kexin type-9 (PCSK9), a serine protease, modulates cholesterol metabolism by attachment to the LDL receptor (LDLR) and reducing its recycling by targeting the receptor for lysosomal destruction. Published research has shown that PCSK9 is also involved in degradation of other LDLR family members namely very-low-density-lipoprotein receptor (VLDLR), lipoprotein receptor-related protein 1 (LRP-1), and apolipoprotein E receptor 2 (ApoER2). As a result, this protein represents an interesting therapeutic target for the treatment of hypercholesterolemia. Interestingly, clinical trials on PCSK9-specific monoclonal antibodies have reported promising results with high efficacy in lowering LDL-C and in turn reducing cardiovascular complications. It is important to note that PCSK9 mediates several other pathways apart from its role in lipid homeostasis, including antiviral activity, hepatic regeneration, neuronal apoptosis, and modulation of various signaling pathways. Furthermore, recent literature has illustrated that PCSK9 is closely associated with incidence and progression of several cancers. In a number of studies, PCSK9 siRNA was shown to effectively suppress the proliferation and invasion of the several studied tumor cells. Hence, a novel application of PCSK9 inhibitors/silencers in cancer/metastasis could be considered. However, due to poor data on effectiveness and safety of PCSK9 inhibitors in cancer, the impact of PCSK9 inhibition in these pathological conditions is still unknown.

SEARCH METHODS

A vast literature search was conducted to find intended studies from 1956 up to 2020, and inclusion criteria were original peer-reviewed publications.

PURPOSE OF REVIEW

To date, PCSK9 has been scantly investigated in cancer. The question that needs to be discussed is "How does PCSK9 act in cancer pathophysiology and what are the risks or benefits associated to its inhibition?". We reviewed the available publications highlighting the contribution of this proprotein convertase in pathways related to cancer, with focus on the potential implications of its long-term pharmacological inhibition in cancer therapy.

Major Depressive Disorder (MDD) and Antidepressant Medication Are Overrepresented in High-Dose Statin Treatment

Objective: To examine the dose-dependent relationship of different types of statins with the occurrence of major depressive disorder (MDD) and prescription of antidepressant medication.

Methods: This cross-sectional study used medical claims data for the general Austrian population (n = 7,481,168) to identify all statin-treated patients. We analyzed all patients with MDD undergoing statin treatment and calculated the average defined daily dose for six different types of statins. In a sub-analysis conducted independently of inpatient care, we investigated all patients on antidepressant medication (statin-treated patients: n = 98,913; non-statin-treated patients: n = 789,683). Multivariate logistic regression analyses were conducted to calculate the risk of diagnosed MDD and prescription of antidepressant medication in patients treated with different types of statins and dosages compared to non-statin-treated patients.

Results: In this study, there was an overrepresentation of MDD in statin-treated patients when compared to non-statin-treated patients (OR: 1.22, 95% CI: 1.20–1.25). However, there was a dose dependent relationship between statins and diagnosis of MDD. Compared to controls, the ORs of MDD were lower for low-dose statin-treated patients (simvastatin>0– < =10 mg:OR: 0.59, 95% CI: 0.54–0.64; atorvastatin>0– < =10 mg:OR:0.65, 95%CI: 0.59–0.70; rosuvastatin>0– < =10 mg:OR: 0.68, 95% CI: 0.53–0.85). In higher statin dosages there was an overrepresentation of MDD (simvastatin>40– < =60 mg:OR: 2.42, 95% CI: 2.18–2.70, >60–80 mg:OR: 5.27, 95% CI: 4.21–6.60; atorvastatin>40– < =60 mg:OR: 2.71, 95% CI: 1.98–3.72, >60– < =80 mg:OR: 3.73, 95% CI: 2.22–6.28; rosuvastatin>20– < =40 mg:OR: 2.09, 95% CI: 1.31–3.34). The results were confirmed in a sex-specific analysis and in a cohort of patients taking antidepressants, prescribed independently of inpatient care.

Conclusions: This study shows that it is important to carefully re-investigate the relationship between statins and MDD. High-dose statin treatment was related to an overrepresentation, low-dose statin treatment to an underrepresentation of MDD.

Searching for a predictive peripherical biological model in parasuicidal behaviour

The aim of this study was to identify possible peripheral biological markers (both lipidic and hormonal) which can be easily used for the early detection of parasuicidal behaviour and to propose a predictive biological model of such behaviour. A case-control analytical study was undertaken at least 3 months after attempted suicide. Study was made of 128 patients who presented at the University General Hospital of Oviedo (Spain) with signs of self-intoxication. Lipidic and hormonal profiles were measured under basal conditions and comparison was made with a control group of healthy volunteer donors obtained from the Oviedo General Hospital blood bank. A discriminant analysis was later made with the aim of establishing a predictive biological model. This included the following variables: cholesterol, HDL-C, LDL-C and cortisol. Sensitivity and specificity were 62.5% and 65.6%, respectively. Replication and improvement of this model, through other prospective studies, could lead to the use of serum cholesterol and cortisol levels as inexpensive and readily available markers of suicide risk.

Associations between very low concentrations of low density lipoprotein cholesterol, high sensitivity C-reactive protein, and health outcomes in the Reasons for Geographical and Racial Differences in Stroke (REGARDS) study

Aims

Recent findings have demonstrated the important contribution of inflammation to the risk of cardiovascular disease (CVD) in individuals with optimally managed low density lipoprotein cholesterol (LDL-C). We explored relationships between LDL-C, high sensitivity C-reactive protein (hs-CRP), and clinical outcomes in a free-living US population.

Methods and results

We used data from the REasons for Geographical And Racial Differences in Stroke (REGARDS), and selected individuals at 'high risk' for coronary events with a Framingham Coronary Risk Score of ≥10% or atherosclerotic cardiovascular disease (ASCVD) risk ≥7.5% in order to explore relationships between low LDL-C [<70 mg/dL (1.8 mmol/L) in comparison to ≥70 mg/dL (1.8 mmol/L)]; hs-CRP <2 compared with ≥2 mg/L and clinical outcomes [all-cause mortality, incident coronary heart disease (CHD), and incident stroke]. To assess the association between the LDL-C and hs-CRP categories and each outcome, a series of incremental Cox proportional hazards models were employed on complete cases. To account for missing observations, the most adjusted model was used to interrogate the data using multiple imputation with chained equations (MICE). In this analysis, 6136 REGARDS high-risk participants were included. In the MICE analysis, participants with high LDL-C (≥70 mg/dL) and low hs-CRP (<2 mg/L) had a lower risk of incident stroke [hazard ratio (HR) 0.69, 0.47-0.997], incident CHD (HR 0.71, 0.53-0.95), and CHD death (HR 0.70, 0.50-0.99) than those in the same LDL-C category high hs-CRP (≥2 mg/L). In participants with high hs-CRP (≥2 mg/dL), low LDL-C [<70 mg/dL (1.8 mmol/L)] was not associated with additional risk reduction of any investigated outcome, but with the significant increase of all-cause mortality (HR 1.37, 1.07-1.74).

Conclusions

In this high-risk population, we found that low hs-CRP (<2 mg/L) appeared to be associated with reduced risk of incident stroke, incident CHD, and CHD death, whereas low LDL-C (<70 mg/dL) was not associated with protective effects. Thus, our results support other data with respect to the importance of inflammatory processes in the pathogenesis of CVD.

The Hypercholesterolemia Paradox in Percutaneous Coronary Intervention: An Analysis of a Multicenter PCI Registry

Objective The aim of this study was to assess the relationship between hypercholesterolemia (HC) and clinical events through a percutaneous coronary intervention (PCI) registry. HC is a well-known independent risk factor for long-term cardiovascular events after PCI. However, it has been reported to be associated with a lower risk of adverse events in patients with cancer or acute coronary syndrome. Methods We analyzed the relationship between HC and adverse events in patients treated with everolimus-eluting stents (EESs) through the Tokyo-MD PCI study (an all-comer, multicenter, observational registry). The propensity score method was applied to select two groups with similar baseline characteristics. Results The unadjusted population included 1,536 HC patients and 330 non-HC patients. Propensity score matching yielded 314 matched pairs. After baseline adjustment, the outcomes of HC patients were significantly better than those of the non-HC patients with respect to the primary endpoint, which was a combination of mortality from all causes, nonfatal myocardial infarction (MI), nonfatal neurological events, and major bleeding [hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.39-0.81; p=0.002], and the secondary endpoints, which included a combination of mortality from all causes, nonfatal MI, and nonfatal neurological events (HR 0.59, 95% CI 0.39-0.88; p=0.01), and major bleeding (HR 0.42, 95% CI 0.20-0.88; p=0.02). A subgroup analysis showed age as an interaction factor for the primary endpoint (interaction p=0.035). Conclusion HC was associated with better outcomes in patients who underwent EES implantation, even after baseline adjustment.

Serum lipid changes following the onset of depressive symptoms in postmenopausal women

A cross-sectional association between depression and serum low-density lipoprotein cholesterol (LDL-c) has been noted in psychiatric literature, raising the question of temporality: does low LDL-c predict depression, does depression lead to changes in LDL-c levels, or is this relationship bidirectional? In a previous longitudinal analysis of postmenopausal women ages 50-79 who participated in the Women's Health Initiative (WHI), we detected an association between low LDL-c and the subsequent onset of depressive symptoms (HR=1.25, 95% CI 1.05-1.49, p=0.01). This current study uses the WHI cohort to explore the question of temporality in the opposite direction, examining the influence of depressive symptoms on subsequent changes in LDL-c levels. This study provides no evidence to suggest an association between depression and subsequent changes in LDL-c level (-2.78mg/dL, 95% CI=-7.49 to 1.92, p=0.25), nor was any association detected for total cholesterol, HDL, or triglyceride changes over time. Further, this study demonstrates that the relationship between depression and serum LDL changes is not mediated by changes in weight, exercise, or energy intake.

Worldwide Exposures to Cardiovascular Risk Factors and Associated Health Effects: Current Knowledge and Data Gaps

Information on exposure to, and health effects of, cardiovascular disease (CVD) risk factors is needed to develop effective strategies to prevent CVD events and deaths. Here, we provide an overview of the data and evidence on worldwide exposures to CVD risk factors and the associated health effects. Global comparative risk assessment studies have estimated that hundreds of thousands or millions of CVD deaths are attributable to established CVD risk factors (high blood pressure and serum cholesterol, smoking, and high blood glucose), high body mass index, harmful alcohol use, some dietary and environmental exposures, and physical inactivity. The established risk factors plus body mass index are collectively responsible for ≈9.7 million annual CVD deaths, with high blood pressure accounting for more CVD deaths than any other risk factor. Age-standardized CVD death rates attributable to established risk factors plus high body mass index are lowest in high-income countries, followed by Latin America and the Caribbean; they are highest in the region of central and eastern Europe and central Asia. However, estimates of the health effects of CVD risk factors are highly uncertain because there are insufficient population-based data on exposure to most CVD risk factors and because the magnitudes of their effects on CVDs in observational studies are likely to be biased. We identify directions for research and surveillance to better estimate the effects of CVD risk factors and policy options for reducing CVD burden by modifying preventable risk factors.

Interpretation of the evidence for the efficacy and safety of statin therapy

This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy-ie, adverse effects of the statin-are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50-100 new cases of diabetes, and 5-10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50-100 patients (ie, 0·5-1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.

African Americans, Depression, and Suicide Risk

The aim of the current study was to determine which variable would be a better predictor of suicide risk: perceived social support or serum cholesterol level. There was a significant negative correlation between suicide risk and perceived social support but no significant correlation between suicide risk and serum cholesterol. Perceived social support was a better predictor of suicide risk than was serum cholesterol level and accounted for 17% of the variance. Depressed patients with a history of suicide attempt had a significantly lower serum cholesterol level, scored significantly higher on the Suicide Risk Scale, and scored significantly lower on the Perceived Social Support Scale than did depressed patients with no history of suicide attempt. Findings suggest that perceived social support is a better predictor of suicide risk for depressed African Americans.

The safety of ezetimibe and simvastatin combination for the treatment of hypercholesterolemia

INTRODUCTION

In the light of the most recent and stricter dyslipidemia treatment guidelines, the need for combination hypolipidemic therapy is increasing. Ezetimibe plus simvastatin is available as a fixed dose therapy offering an efficient hypolipidemic treatment choice. Based on the positive results of the IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) trial, the use of this drug combination is expected to increase in the next years.

AREAS COVERED

This review discusses the current evidence regarding the safety of ezetimibe/simvastatin combination. Current evidence regarding possible associated side effects (musculoskeletal, gastrointestinal, endocrine, hematological, renal, ophthalmologic, allergic, malignancy) and drug interactions of this combination is thoroughly discussed.

EXPERT OPINION

Ezetimibe and simvastatin treatment, either as a single pill or the combined use of the individual compounds, offers limited additional risk compared with simvastatin monotherapy and comprises a safe and efficient choice for dyslipidemia treatment in high-risk and diabetic patients.

Longitudinal study of low serum LDL cholesterol and depressive symptom onset in postmenopause

OBJECTIVE

The aim of this study was to characterize the relationship between serum low-density lipoprotein cholesterol (LDL-c) and subsequent depressive symptoms onset in postmenopausal women. We secondarily assessed serum high-density lipoprotein (HDL-c), total cholesterol, and triglycerides.

METHOD

This population-based prospective cohort study utilizes data from 24,216 women between 50 and 79 years of age who were participants of the Women's Health Initiative, which originally ran from 1993 to 2005 and has since incorporated 2 extension studies, with the most recent culminating in 2015. Fasting lipids were measured for all participants at baseline and for a subset through 6 years of follow-up. Depressive symptoms were characterized using the Burnam 8-item scale for depressive disorders (Center for Epidemiologic Studies-Depression/Diagnostic Interview Schedule short form) at baseline and during follow-up, using a cut point of 0.06 to indicate presence of depressive symptoms.

RESULTS

The lowest quintile of LDL-c was associated with an increased risk of subsequent depressive symptoms (hazard ratio [HR] = 1.25, 95% CI = 1.05-1.49, P = .01), and follow-up analyses demonstrated that the elevated risk appeared to be confined to the lowest decile (LDL-c < 100 mg/dL). Further, this elevated risk was moderated by lipid-lowering drug treatment. Elevated risk was demonstrated among those who reported no lipid-lowering medication use (HR = 1.23, 95% CI = 1.03-1.47, P = .02), but not among those reporting use (HR = 0.65, 95% CI = 0.18-2.29, P = .50).

CONCLUSIONS

Among postmenopausal women, untreated serum LDL-c below 100 mg/dL was associated with an increased risk of developing depressive symptoms. No excess risk was observed in those attaining LDL-c < 100 mg/dL with lipid-lowering therapy. These findings have important implications for risk assessment, treatment considerations, and mechanistic insight.

Low HDL cholesterol but not high LDL cholesterol is independently associated with subclinical coronary atherosclerosis in healthy octogenarians

AIM OF THE STUDY

Although low-density lipoprotein cholesterol (LDL-C) has been consistently demonstrated a predictor of atherosclerotic disease in a large spectrum of clinical settings, among individuals aged of 80 years or older this concept is uncertain. This study was evaluated in a carefully selected population if the association between LDL-C and coronary atherosclerotic burden remains significant in the very elderly.

METHODS

Individuals aged of 80 years or older (n = 208) who spontaneously sought primary prevention care and have never manifested cardiovascular disease, malnutrition, neoplastic or consumptive disease were enrolled for a cross-sectional analysis. Medical evaluation, anthropometric measurements, blood tests and cardiac computed tomography were obtained.

RESULTS

In analyses adjusted for age, gender, diabetes, systolic and diastolic blood pressure, smoking and statin therapy, no association was found between coronary calcium score (CCS) and LDL-C [1.79 (0.75-4.29)]. There was no association between triglycerides and CCS. The association between high-density lipoprotein cholesterol (HDL-C) and CCS was significant and robust in unadjusted [0.32 (0.15-0.67)] as well as in the fully adjusted analysis [0.34 (0.15-0.75)].

CONCLUSION

The present study confirms in a healthy cohort of individuals aged of 80 years or more that while the association between LDL-C and coronary atherosclerosis weakens with aging, the opposite occurs with the levels of HDL-C.

HMG-CoA reductase inhibitors as adjuvant treatment for hematologic malignancies: what is the current evidence?

Statins have been shown to possess properties that go beyond their lipid-lowering effects. These agents act on the mevalonate pathway and inhibit synthesis of cholesterol, geranylgeranyl pyrophosphate, and farnesyl pyrophosphate, which are necessary for posttranslational modification of the Rho, Rac, and Ras superfamily of proteins. Early phase studies have demonstrated that this modulation of cellular signaling can ultimately exert pro-apoptotic, anti-angiogenic, and immunomodulatory effects, and might even restore chemosensitivity in several hematologic cancers. Nonetheless, these promising preclinical results have not yet migrated from the bench to the bedside as their effectiveness as adjuvant agents in hematologic malignancies is currently uncertain. In the present review, we summarize the existing evidence stemming from preclinical and clinical studies pertaining to the use of statins as adjuvant therapies in hematologic malignancies, and discuss the new insights gained from the ongoing translational research.

Tumor macroenvironment and metabolism

In this review we introduce the concept of the tumor macroenvironment and explore it in the context of metabolism. Tumor cells interact with the tumor microenvironment including immune cells. Blood and lymph vessels are the critical components that deliver nutrients to the tumor and also connect the tumor to the macroenvironment. Several factors are then released from the tumor itself but potentially also from the tumor microenvironment, influencing the metabolism of distant tissues and organs. Amino acids, and distinct lipid and lipoprotein species can be essential for further tumor growth. The role of glucose in tumor metabolism has been studied extensively. Cancer-associated cachexia is the most important tumor-associated systemic syndrome and not only affects the quality of life of patients with various malignancies but is estimated to be the cause of death in 15%-20% of all cancer patients. On the other hand, systemic metabolic diseases such as obesity and diabetes are known to influence tumor development. Furthermore, the clinical implications of the tumor macroenvironment are explored in the context of the patient's outcome with special consideration for pediatric tumors. Finally, ways to target the tumor macroenvironment that will provide new approaches for therapeutic concepts are described.

Reshaping diabetes care: the fundamental role of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists in clinical practice

OBJECTIVE

To update clinicians on the most recent safety and efficacy data on current incretin-based strategies for the treatment of type 2 diabetes (T2D).

METHODS

Title searches were conducted in the Pubmed database to identify literature pertaining to the safety and efficacy of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors. Product-specific title searches included the terms exenatide, liraglutide, linagliptin, saxagliptin, sitagliptin, and vildagliptin.

RESULTS

The recent literature has introduced us to newer DPP-4 inhibitors and longer-acting GLP-1RAs, updated meta-analyses assessing the safety and efficacy of incretin-based therapies, and studies exploring the use of incretin-based treatments in broader clinical settings such as combination therapy with insulin. Meta-analyses have demonstrated placebo-adjusted glycated hemoglobin (HbA1c) reductions of ~1% with GLP-1RAs and 0.6 to 0.8% with DPP-4 inhibitors and have suggested cardioprotective effects such as reduction of cardiovascular events and improvement of lipid profile. As a class, these agents have consistently demonstrated low risks of hypoglycemia relative to other agents.

CONCLUSION

Incretin-based therapies are characterized by an overall favorable safety profile and weight effect, a low risk of hypoglycemia, and clinically meaningful improvements in HbA1c. Based on an expanding and favorable literature describing their use in various patient populations, the guidelines of the American Association of Clinical Endocrinologists and the recently updated guidelines from the American Diabetes Association assign these agents a central role in the treatment of T2D.

A prospective study of statin use and poststroke depression

Associations between serum cholesterol levels or lipid-lowering treatment and depression risk have been controversial. Associations between statin use and depression risk have been investigated in patients with coronary artery diseases but have not been examined after stroke. This study aimed to investigate whether statin use was associated with depression ascertained at 2 weeks and 1 year after stroke. A total of 423 patients were evaluated 2 weeks after stroke, and 288 (68%) were followed 1 year later. At the 2 examinations, depression (major or minor depressive disorder) was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria, and depression severity was assessed by the Hospital Anxiety and Depression Scale-Depression subscale and the Hamilton Depression Rating Scale. Logistic regression and repeated-measures analyses of variance were carried out. Statins were used in 251 (59%) of 423 patients at baseline. Statin use was not associated with poststroke depression (PSD) status at baseline but was significantly associated with reduced risk of all PSD, and of major PSD specifically, at follow-up. Statin use was also associated with better trajectories of depression assessment scale scores over the 1-year follow-up. Statin use was associated with a reduced risk of depression at 1 year after stroke. Likely causality and underlying mechanisms need to be further clarified.

Effects of adjuvant aromatase inhibitor therapy on lipid profiles

How aromatase inhibitors affect lipids is of great interest. Compared with tamoxifen, adjuvant anastrozole and letrozole are associated with increased incidences of hypercholesterolemia, while similar data are lacking for exemestane in the adjuvant setting. No significant differences in lipid profiles occurred with extended adjuvant exemestane compared with placebo, but total cholesterol and low-density lipoprotein levels increased significantly above baseline in both groups over 6 months. Likewise, no significant differences in hypercholesterolemia rates occurred between extended adjuvant letrozole and placebo. A lipid substudy further confirmed that letrozole did not significantly alter serum lipids for 36 months compared with placebo. Thus, although aromatase inhibitors lack the lipid-lowering properties of tamoxifen, no significant worsening of lipid levels occurs with their use. Patients would benefit from lifestyle changes and routine monitoring of serum lipids. Breast cancer therapy trials often report serum lipid parameters, but assessing the quality and overall significance of the data can be difficult. Methodology of data collection varies among trials and the concomitant use of lipid-modifying medication is often not reported. This review discusses the current understanding of the influence of lipid levels on cardiovascular risk in women and presents key findings on the effects of adjuvant aromatase inhibitor therapy on lipid profiles.

Incretin-based therapies: focus on effects beyond glycemic control alone

Type 2 diabetes is associated with a high prevalence of comorbidities resulting from hypertension, dyslipidemia, and hyperglycemia. Inadequate management of these risk factors will eventually result in detrimental health consequences. Thus, the effect of a drug on factors such as weight, cardiovascular (CV) risk factors, and adherence is important to consider. A review was undertaken of the recent medical literature describing the extraglycemic characteristics of the two classes of incretin-based therapies-glucagon-like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 (DPP-4) inhibitors. PubMed searches were performed to identify published data on incretin therapies that describe their effects on CV risk factors, CV events, and factors related to medication adherence. The maintenance or loss of weight associated with the use of GLP-1RAs and DPP-4 inhibitors is well described in the medical literature. These agents also appear to be associated with a modest decrease in blood pressure and a reduced risk of CV events. In addition, several characteristics of incretin therapies may improve rates of medication adherence, such as generally favorable tolerability profiles (particularly with DPP-4 inhibitors), the availability of formulations that simplify treatment regimens, and a low risk for hypoglycemia. The literature on incretin therapies describes a number of clinical characteristics that are relevant to the management of extraglycemic risk factors. As part of a holistic treatment strategy, these properties constitute important considerations for tailoring therapy to individual patients with type 2 diabetes.

New therapeutic alternatives for the management of dyslipidemia

Hypercholesterolemia affects over 34 million adults in the United States and is a major cause of coronary heart disease (CHD). Conventional therapies, such as statins, have demonstrated their ability to improve clinical end points and decrease morbidity and mortality in patients with CHD. Lomitapide (Juxtapid(®)), mipomersen (Kynamro(®)), and icosapent (Vascepa(®)) are 3 novel agents approved by the US Food and Drug Administration in the past 2 years, which offer new lipid-lowering treatment options with unique pharmacology.

The age-specific quantitative effects of metabolic risk factors on cardiovascular diseases and diabetes: a pooled analysis

BACKGROUND

The effects of systolic blood pressure (SBP), serum total cholesterol (TC), fasting plasma glucose (FPG), and body mass index (BMI) on the risk of cardiovascular diseases (CVD) have been established in epidemiological studies, but consistent estimates of effect sizes by age and sex are not available.

METHODS

We reviewed large cohort pooling projects, evaluating effects of baseline or usual exposure to metabolic risks on ischemic heart disease (IHD), hypertensive heart disease (HHD), stroke, diabetes, and, as relevant selected other CVDs, after adjusting for important confounders. We pooled all data to estimate relative risks (RRs) for each risk factor and examined effect modification by age or other factors, using random effects models.

RESULTS

Across all risk factors, an average of 123 cohorts provided data on 1.4 million individuals and 52,000 CVD events. Each metabolic risk factor was robustly related to CVD. At the baseline age of 55-64 years, the RR for 10 mmHg higher SBP was largest for HHD (2.16; 95% CI 2.09-2.24), followed by effects on both stroke subtypes (1.66; 1.39-1.98 for hemorrhagic stroke and 1.63; 1.57-1.69 for ischemic stroke). In the same age group, RRs for 1 mmol/L higher TC were 1.44 (1.29-1.61) for IHD and 1.20 (1.15-1.25) for ischemic stroke. The RRs for 5 kg/m(2) higher BMI for ages 55-64 ranged from 2.32 (2.04-2.63) for diabetes, to 1.44 (1.40-1.48) for IHD. For 1 mmol/L higher FPG, RRs in this age group were 1.18 (1.08-1.29) for IHD and 1.14 (1.01-1.29) for total stroke. For all risk factors, proportional effects declined with age, were generally consistent by sex, and differed by region in only a few age groups for certain risk factor-disease pairs.

CONCLUSION

Our results provide robust, comparable and precise estimates of the effects of major metabolic risk factors on CVD and diabetes by age group.

Safety and effect of very low levels of low-density lipoprotein cholesterol on cardiovascular events

Based on the cardiovascular (CV) outcomes data derived predominantly from 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor (statin) trials, guidelines have set low-density lipoprotein (LDL) cholesterol targets at successively lower levels over time. Recent data have demonstrated that more-intensive statin therapy (and, consequently, lower LDL cholesterol level) is more effective at reducing CV events than less-intensive statin therapy. Although the average LDL cholesterol level for a United States adult is 119 mg/dl, within the "normal" range (90 to 130 mg/dl) per the United States National Cholesterol Education Program-Adult Treatment Panel III guidelines, data from fetal studies, diet studies, contemporary hunter-gatherer populations, and other mammals have suggested that the "normal" physiologic range for LDL cholesterol in humans is likely 50 to 70 mg/dl. Low LDL cholesterol levels have been sporadically associated with an increased risk of cancer, hemorrhagic stroke, and other complications in population studies and clinical trials. However, statin clinical trials have generally not demonstrated correlations between on-treatment LDL cholesterol levels and safety. Clinical data have suggested a linear relation between LDL cholesterol lowering and CV risk reduction, supporting a favorable risk/benefit ratio for attaining very low levels of LDL cholesterol to minimize the risk of CV events. In conclusion, clinical trial evidence demonstrating the efficacy and safety of LDL cholesterol lowering to a very low level is essential to ascertain the benefits and risks in reducing the residual risk of vascular disease.

Increases in triglyceride levels are associated with clinical response to clozapine treatment

Increases in serum triglyceride (TG) levels are associated with clinical response to clozapine treatment. Clozapine is the most efficacious therapy for treatment of refractory schizophrenia, although its use is well recognised to be associated with substantial metabolic dysfunction. Interestingly, there is some evidence that the therapeutic benefit of clozapine is associated with treatment-emergent weight gain and dyslipidaemia, specifically hypertriglyceridaemia. In this prospective observational study, we examine associations between therapeutic response to clozapine in 49 patients with treatment-resistant schizophrenia and lipid dysregulation. An increase in TG levels was strongly predictive of clinical improvement (B=9.33, t =3.56, df=4, p<0.001) and of improvement in positive PANSS scores (B=2.85, t=3.61, df=4, p=0.001) as well as negative PANSS scores (B=1.93, t=2.36, df=4, p=0.02), when controlling for potential confounds of weight gain, change in waist circumference, baseline antipsychotic polypharmacy and serum clozapine levels. This finding suggests that clozapine's therapeutic efficacy is linked to serum lipid changes. Hypertriglyceridaemia as a predictor of clinical response in patients treated with clozapine merits further investigation in order to better elucidate its effect on the pharmacological activity of clozapine.

Low cholesterol as a risk factor for primary intracerebral hemorrhage: A case-control study

Introduction:

An inverse association between serum cholesterol and the risk of hemorrhagic stroke has been noted in epidemiological studies. We performed a case–control study to assess the relationship between primary intracerebral hemorrhage (ICH) and low serum cholesterol.

Materials and Methods:

Prospectively recruited fully evaluated patients with ICH were compared with a control group based in a primary care practice, i.e. age- and sex-matched individuals attending the routine preventive health check-up. Low cholesterol was defined by the sex-specific lowest quintile of the population.

Results:

The proportion of ICH patients with low cholesterol was significantly higher than the controls (68% vs. 43%). Mean total cholesterol was also signficantly low in ICH patients compared with controls (177 mg/dL vs. 200 mg/dl; P-value = 0.0006). Low-density lipoprotein cholesterol (LDL-c) and triglycerides were also significantly low in ICH patients compared with controls. Mean LDL-C in the ICH patient group was 114 mg/dL, whereas it was 128.5 mg/dL in the control group (P-value = 0.016). There was no significant difference in the high-density lipoprotein (HDL) levels in both groups. In a subgroup analysis, both men and women in the ICH group had a significantly low mean cholesterol compared with the control group. Although lower mean cholesterol was seen in both young and older individuals in the ICH group than in controls, the difference was significant only in the older group (age >45 years). In multivariate analysis, presence of low cholesterol remained a significant predictor of hemorrhage. The odds ratio of low cholesterol in the hemorrhage cases was 2.75 (95% CI = 1.44–5.49) unadjusted and 2.15 (1.13–4.70) adjusted for age and hypertension.

Conclusions:

This study confirms an increased risk of primary ICH associated with low cholesterol both in men and women, especially in older individuals.

Quality of systematic reviews of observational nontherapeutic studies

INTRODUCTION

High-quality epidemiologic research is essential in reducing chronic diseases. We analyzed the quality of systematic reviews of observational nontherapeutic studies.

METHODS

We searched several databases for systematic reviews of observational nontherapeutic studies that examined the prevalence of or risk factors for chronic diseases and were published in core clinical journals from 1966 through June 2008. We analyzed the quality of such reviews by using prespecified criteria and internal quality evaluation of the included studies.

RESULTS

Of the 145 systematic reviews we found, fewer than half met each quality criterion; 49% reported study flow, 27% assessed gray literature, 2% abstracted sponsorship of individual studies, and none abstracted the disclosure of conflict of interest by the authors of individual studies. Planned, formal internal quality evaluation of included studies was reported in 37% of systematic reviews. The journal of publication, topic of review, sponsorship, and conflict of interest were not associated with better quality. Odds of formal internal quality evaluation (odds ratio [OR], 1.10 per year; 95% confidence interval [CI], 1.02-1.19) and either planned, formal internal quality evaluation or abstraction of quality criteria of included studies (OR, 1.17 per year; 95% CI, 1.08-1.26) increased over time, without positive trends in other quality criteria from 1990 through June 2008. Systematic reviews with internal quality evaluation did not meet other quality criteria more often than those that ignored the quality of included studies.

CONCLUSION

Collaborative efforts from investigators and journal editors are needed to improve the quality of systematic reviews.

Statin use and cancer risk: a comprehensive review

IMPORTANCE OF THE FIELD

HMG-CoA inhibitors (statins), a class of drugs that reduce cholesterol, are used to manage and prevent coronary heart disease. They are among the most commonly prescribed drugs worldwide. Contrary to early concerns over the carcinogenicity of statins, a growing body of evidence suggests statins may in fact have a chemopreventive potential against cancer.

AREAS COVERED IN THIS REVIEW

In this paper, we review evidence on the association between statin use and cancer risk. Specifically, we report on clinical trials and observational studies that measured all cancer or site-specific cancers of the breast, colorectal, lung, prostate and reproductive organs associated with statin use.

WHAT THE READER WILL GAIN

An understanding of the evidence, including strengths and limitations, to support an association between statins and cancer. Information on the current state of the field and future directions are also discussed.

TAKE HOME MESSAGE

Few strong or consistent associations between statins and cancer incidence overall or for any of the sites reviewed were detected. Data for any effects of statins on cancer prognosis and secondary prevention are lacking; with the exception of consistent evidence that statins are associated with reduced risk of advanced/aggressive prostate cancer. Statins appear safe in relation to cancer risk but any chemopreventive effect in humans remains to be established and should not be recommended outside the context of clinical trials. It is encouraging that numerous trials are ongoing. The prospect of reducing the incidence and burden of some of the most prevalent cancers with safe, affordable and tolerable medication that already reduces the risk of the leading cause of death and cardiovascular disease warrants further exploration in clinical trials and observational studies of prognosis and survival.

[Advances in cholesterol-lowering interventions]

Numerous epidemiological and prospective studies have shown a direct relationship between total cholesterol and low-density lipoprotein cholesterol (LDL-C) and cardiovascular disease (cardiovascular morbidity and mortality). In many intervention studies with more than 100,000 subjects, statins have shown a powerful and significant reduction of cardiovascular events and a decrease in cardiovascular and overall mortality, far superior to those produced by any other lipid-lowering group. Consequently statins are considered to be safe and well tolerated and are the first choice in the treatment of hypercholesterolemia and in cardiovascular disease prevention. If targets are not reached, other pharmacological groups must be associated (resins, nicotinic acid, ezetimibe, fibrates, etc.). Moreover, when hypercholesterolemia is associated with low concentrations of high-density lipoprotein (HDL)-cholesterol and high triglyceride levels, the association of statins with nicotinic acid, fibrates or omega-3 should be considered. Some questions remain to be answered: what LDL-C levels are desirable in secondary prevention? Which individuals might benefit from treatment in primary prevention? Which lipid-lowering drug is the most suitable to combine with statins and diminish cardiovascular risk in each situation? The present article reviews these important points.

Lipid-lowering drugs and risk for cancer

The suspicion that lipid-lowering drugs might increase the risk for cancer has been present for three decades and has been the reason for intense debate and several attempts to reanalyze data from clinical trials. Recently, the results of the Simvastatin and Ezetimibe in Aortic Stenosis study sparked new interest in this problem, as the intense lipid-lowering therapy seems to have increased the number of cancers compared with the control group. This article gives an overview of the clinical evidence from trials and observational studies. As of now, the evidence is inconclusive, but there does not appear to be a reason for serious concern with short-term therapy. Whether statins and other lipid-lowering drugs will increase the risk of cancer when used over several decades is at present unknown.

Session 4: Challenges facing the food industry in innovating for health. Impact on CVD risk of modifying milk fat to decrease intake of SFA and increase intake of cis-MUFA

Despite the acknowledged benefits of reducing SFA intake few countries within the EU meet recognised targets. Milk and dairy products represent the single largest source of dietary SFA in most countries, yet epidemiological evidence indicates that milk has cardioprotective properties such that simply reducing consumption of dairy foods to meet SFA targets may not be a sound public health approach. The present paper explores the options for replacing some of the SFA in milk fat with cis-MUFA through alteration of the diet of the dairy cow, and the evidence that such changes can improve the indicators for CHD and CVD in general for the consumer. In addition, the outcome of such changes on risk factors for CHD and CVD at the population level is examined in the light of a modelling exercise involving data for eleven EU member states. Given the current and projected costs of health care, the results indicate that urgent consideration should be given to such a strategy.

History of the cholesterol controversy in Britain

The lipid hypothesis, the concept that cholesterol plays a causal role in atherosclerosis and cardiovascular disease, has been the subject of a controversy which started in the 1950s, peaked in the 1970s and 80s and then subsided in the 1990s. It was finally resolved by the positive outcome of the Scandinavian Simvastatin Survival Study, the first of 14 prevention trials using statins which showed that lowering cholesterol reduced both cardiovascular events and total mortality. This commentary focuses primarily on the events and people involved in the cholesterol controversy in Britain. The foremost critics of the lipid hypothesis are now deceased but unfortunately for many of the patients with hypercholesterolaemia and coronary heart disease it took the best part of 50 years to disprove the sceptics. This brief account relates why it took so long.

PPARα Agonist-Induced Rodent Tumors: Modes of Action and Human Relevance

Widely varied chemicals--including certain herbicides, plasticizers, drugs, and natural products--induce peroxisome proliferation in rodent liver and other tissues. This phenomenon is characterized by increases in the volume density and fatty acid oxidation of these organelles, which contain hydrogen peroxide and fatty acid oxidation systems important in lipid metabolism. Research showing that some peroxisome proliferating chemicals are nongenotoxic animal carcinogens stimulated interest in developing mode of action (MOA) information to understand and explain the human relevance of animal tumors associated with these chemicals. Studies have demonstrated that a nuclear hormone receptor implicated in energy homeostasis, designated peroxisome proliferator-activated receptor alpha (PPARalpha), is an obligatory factor in peroxisome proliferation in rodent hepatocytes. This report provides an in-depth analysis of the state of the science on several topics critical to evaluating the relationship between the MOA for PPARalpha agonists and the human relevance of related animal tumors. Topics include a review of existing tumor bioassay data, data from animal and human sources relating to the MOA for PPARalpha agonists in several different tissues, and case studies on the potential human relevance of the animal MOA data. The summary of existing bioassay data discloses substantial species differences in response to peroxisome proliferators in vivo, with rodents more responsive than primates. Among the rat and mouse strains tested, both males and females develop tumors in response to exposure to a wide range of chemicals including DEHP and other phthalates, chlorinated paraffins, chlorinated solvents such as trichloroethylene and perchloroethylene, and certain pesticides and hypolipidemic pharmaceuticals. MOA data from three different rodent tissues--rat and mouse liver, rat pancreas, and rat testis--lead to several different postulated MOAs, some beginning with PPARalpha activation as a causal first step. For example, studies in rodent liver identified seven "key events," including three "causal events"--activation of PPARalpha, perturbation of cell proliferation and apoptosis, and selective clonal expansion--and a series of associative events involving peroxisome proliferation, hepatocyte oxidative stress, and Kupffer-cell-mediated events. Similar in-depth analysis for rat Leydig-cell tumors (LCTs) posits one MOA that begins with PPARalpha activation in the liver, but two possible pathways, one secondary to liver induction and the other direct inhibition of testicular testosterone biosynthesis. For this tumor, both proposed pathways involve changes in the metabolism and quantity of related hormones and hormone precursors. Key events in the postulated MOA for the third tumor type, pancreatic acinar-cell tumors (PACTs) in rats, also begin with PPARalpha activation in the liver, followed by changes in bile synthesis and composition. Using the new human relevance framework (HRF) (see companion article), case studies involving PPARalpha-related tumors in each of these three tissues produced a range of outcomes, depending partly on the quality and quantity of MOA data available from laboratory animals and related information from human data sources.

Are cholesterol and depression inversely related? A meta-analysis of the association between two cardiac risk factors

BACKGROUND

Cholesterol and depression are both cardiac risk factors, but the direction and magnitude of the association between these risk factors is unclear.

PURPOSE

Meta-analytic techniques were used to evaluate the associations among total, high-, and low-density cholesterol (TC, HDL, LDL, respectively) and depression in empirical studies.

METHODS

PubMed, CINAHL, PsycINFO, and manual search strategies were used to identify descriptive studies reporting associations among TC, HDL, LDL, and depression; 30 reports were found for TC, 16 for HDL, and 11 for LDL. Effect sizes were computed and aggregated in accord with Hedges and Olkin's (Statistical methods for meta-analysis. New York: Academic Press; 1985) procedures.

RESULTS

Higher TC was associated with lower levels of depression, d = -0.29; this association was substantially larger among medication-free samples (d = -0.51). An inverse, non-significant association was observed between LDL and depression (d = -0.17). High HDL was related to higher levels of depression, especially in women (d = 0.20).

CONCLUSIONS

TC and depression were inversely related, with the strongest associations in medically naïve samples, which is noteworthy because such samples should involve fewer confounds. One clinical implication is that the lipids of patients treated for depression should be monitored.

Misleading associations between cholesterol and vascular outcomes in dialysis patients: the need for randomized trials

Higher cholesterol is strongly associated with an increased risk of coronary heart disease (CHD) in nonrenal populations, so the lack of a clear positive association between total cholesterol and mortality among dialysis patients is unexpected. This review of prospective studies of the association between total cholesterol and mortality among dialysis patients suggests that there is a negative association at below average cholesterol levels and a flat or weakly positive association at higher levels. In nonrenal populations total cholesterol is not positively associated with vascular causes of death other than CHD, so the lack of a strongly positive association at above average cholesterol concentrations in dialysis patients may be explained by the high proportion of deaths due to non-CHD vascular causes. The observation of a negative association between total cholesterol and mortality at below average cholesterol concentrations in some studies is consistent with confounding by both vascular and nonvascular morbidity (i.e., reverse causality). We argue that evaluating the importance of cholesterol for vascular disease risk in dialysis patients can only be achieved through the eradication of confounding by randomization, and that ongoing trials of cholesterol-lowering therapy will provide a definitive answer to this question.

Blood cholesterol and vascular mortality by age, sex, and blood pressure: a meta-analysis of individual data from 61 prospective studies with 55,000 vascular deaths

BACKGROUND

Age, sex, and blood pressure could modify the associations of total cholesterol (and its main two fractions, HDL and LDL cholesterol) with vascular mortality. This meta-analysis combined prospective studies of vascular mortality that recorded both blood pressure and total cholesterol at baseline, to determine the joint relevance of these two risk factors.

METHODS

Information was obtained from 61 prospective observational studies, mostly in western Europe or North America, consisting of almost 900,000 adults without previous disease and with baseline measurements of total cholesterol and blood pressure. During nearly 12 million person years at risk between the ages of 40 and 89 years, there were more than 55,000 vascular deaths (34,000 ischaemic heart disease [IHD], 12,000 stroke, 10,000 other). Information about HDL cholesterol was available for 150,000 participants, among whom there were 5000 vascular deaths (3000 IHD, 1000 stroke, 1000 other). Reported associations are with usual cholesterol levels (ie, corrected for the regression dilution bias).

FINDINGS

1 mmol/L lower total cholesterol was associated with about a half (hazard ratio 0.44 [95% CI 0.42-0.48]), a third (0.66 [0.65-0.68]), and a sixth (0.83 [0.81-0.85]) lower IHD mortality in both sexes at ages 40-49, 50-69, and 70-89 years, respectively, throughout the main range of cholesterol in most developed countries, with no apparent threshold. The proportional risk reduction decreased with increasing blood pressure, since the absolute effects of cholesterol and blood pressure were approximately additive. Of various simple indices involving HDL cholesterol, the ratio total/HDL cholesterol was the strongest predictor of IHD mortality (40% more informative than non-HDL cholesterol and more than twice as informative as total cholesterol). Total cholesterol was weakly positively related to ischaemic and total stroke mortality in early middle age (40-59 years), but this finding could be largely or wholly accounted for by the association of cholesterol with blood pressure. Moreover, a positive relation was seen only in middle age and only in those with below-average blood pressure; at older ages (70-89 years) and, particularly, for those with systolic blood pressure over about 145 mm Hg, total cholesterol was negatively related to haemorrhagic and total stroke mortality. The results for other vascular mortality were intermediate between those for IHD and stroke.

INTERPRETATION

Total cholesterol was positively associated with IHD mortality in both middle and old age and at all blood pressure levels. The absence of an independent positive association of cholesterol with stroke mortality, especially at older ages or higher blood pressures, is unexplained, and invites further research. Nevertheless, there is conclusive evidence from randomised trials that statins substantially reduce not only coronary event rates but also total stroke rates in patients with a wide range of ages and blood pressures.

Apolipoprotein E polymorphism, age and coronary heart disease

Plasma concentrations of lipids, lipoproteins, and apolipoproteins (apo) are established risk factors for coronary heart disease (CHD). The knowledge of lipid profile may predict the potential victims of cardiovascular disease before its initiation and progression and offer the opportunity for primary prevention. The most common apo E polymorphism has been found to influence blood lipid concentrations and its correlation with CHD has been extensively investigated in the last decade. At younger ages, death from CHD is influenced by genetic factors, while the genetic effect decreases at older ages where environmental factors may play a more prominent role. If apo E polymorphism is an important genetic factor in the pathogenesis of atherosclerosis, it could affect the age of CHD onset. This review analyses the influence of apo E polymorphism on blood lipids and CHD in respect to age.

Cholesterol and suicide attempts: a prospective study of depressed inpatients

Low cholesterol levels have commonly been associated with various suicide measures. We sought to examine suicide attempts in a prospective sample of depressed patients that on prior analysis demonstrated an association between low cholesterol and subsequent suicide completions. Seventy-four inpatients with Research Diagnostic Criteria unipolar major depression, bipolar depression or schizoaffective depression entered a prospective follow-up study from 1978 to 1981. Kaplan-Meier survival analysis and Cox regression were utilized to elucidate the relationship between cholesterol levels and subsequent severe suicide attempts as well as all suicide attempts regardless of severity. Attempts preceding index hospitalization and other lifetime attempts were evaluated cross-sectionally. Low serum cholesterol levels did not predict subsequent suicide attempts. Contrary to our hypothesis, the high cholesterol group was associated with increased risk of suicide attempts on survival analysis in those less than median age. Nonetheless, in cross-sectional analysis, the low cholesterol group had more suicide attempts preceding index hospitalization and more remote lifetime attempts. The results from this prospective dataset do not support an association between low cholesterol and subsequent suicide attempts despite replicating the retrospective findings of previous case-control and cross-sectional studies.

Neuropsychiatric consequences of cardiovascular medications

The use of cardiovascular medications can have a variety of neuropsychiatric consequences. Many cardiovascular agents cause higher rates of fatigue and sedation than placebo, and case reports of medication-induced mood syndromes, psychosis, and cognitive disturbances exist for many cardiovascular drugs. Depression has been associated with β-blockers, methyldopa, and reserpine, but more recent syntheses of the data have suggested that these associations are much weaker than originally believed. Though low cholesterol levels have been associated with depression and suicide, lipid-lowering agents have not been associated with these adverse effects. Finally, cardiovascular medications may have beneficial neuropsychiatric consequences; for example, the use of clonidine in patients with attention deficit-hyperactivity disorder, the use of prazosin for patients with post-traumatic stress disorder, and the use of propranolol for performance anxiety and akathisia.

Squalene Synthase Inhibitors

HMG-CoA reductase inhibitors (statins) reduce cardiovascular disease morbidity and mortality with a high level of safety. Nonetheless, there are substantial numbers of people who either do not tolerate statins or whose low-density lipoprotein (LDL) levels are not lowered adequately. For these reasons, there is a need to develop other cholesterol-lowering drugs. A target for these new agents is provided by the enzymes distal to HMG-CoA reductase in the cholesterol biosynthesis pathway. Two classes of drugs have been developed: (i) squalene synthase inhibitors, which act at the first committed step in cholesterol biosynthesis, distal to the mevalonate-farnesyl diphosphate pathway; and (ii) oxidosqualene cyclase inhibitors, which act distal to the squalene intermediate. Of these, squalene synthase inhibitors have received more attention and are the subject of this review. Squalene synthase inhibitors decrease circulating LDL-cholesterol by the induction of hepatic LDL receptors in a similar manner to statins. They have fewer secondary effects mediated by a decrease in non-cholesterol products of mevalonate metabolism distal to HMG-CoA reductase, but have the potential to increase intermediates proximal to squalene. Squalene synthase inhibitors are just now entering clinical trials and data on how effectively they lower LDL-cholesterol and how they compliment the actions of statins and other agents is awaited with considerable interest.

Neuropsychiatric consequences of cardiovascular medications

The use of cardiovascular medications can have a variety of neuropsychiatric consequences. Many cardiovascular agents cause higher rates of fatigue and sedation than placebo, and case reports of medication-induced mood syndromes, psychosis, and cognitive disturbances exist for many cardiovascular drugs. Depression has been associated with P3-blockers, methyldopa, and reserpine, but more recent syntheses of the data have suggested that these associations are much weaker than originally believed. Though low cholesterol levels have been associated with depression and suicide, lipid-lowering agents have not been associated with these adverse effects. Finally, cardiovascular medications may have beneficial neuropsychiatric consequences; for example, the use of clonidine in patients with attention deficit-hyperactivity disorder, the use of prazosin for patients with post-traumatic stress disorder; and the use of propranolol for performance anxiety and akathisia.

Low Alanine Aminotransferase Activity in Older People Is Associated with Greater Long-Term Mortality

OBJECTIVES

To find possible association between liver enzymes and mortality in older people.

DESIGN

A prospective cohort study.

SETTING

Jerusalem.

PARTICIPANTS

A systematically selected representative sample of 455 70-year-old ambulatory individuals was prospectively followed for 12 years.

MEASUREMENTS

An extensive social and medical profile was developed at age 70 using a detailed interview and physical and ancillary examination. Information on mortality was obtained annually. Differences in survival between subjects stratified according to liver enzyme levels were assessed using the Kaplan-Meier method. Multivariable survival analyses using a Cox proportional hazards model were performed to determine the association between liver enzyme levels at age 70 and mortality over 12 years.

RESULTS

Median alanine aminotransferase (ALT) activity of the study population was 11.00 U/L for women and 13.00 U/L for men. Twelve-year survival rates for women with ALT below and above the median levels were similar (78%). For men, these rates were 54% and 65%, respectively (P < .001). Proportional hazards models demonstrated that this greater mortality risk was independent of numerous common risk factors for mortality (hazard ratio (HR) = 1.5, 95% confidence interval (CI) = 1.08-2.19). Adding an interaction between sex and low ALT to the model demonstrated a higher risk of mortality for men with low ALT levels (HR = 2.42, 95% CI = 1.15-5.08). No such risk was demonstrated for the other liver enzymes.

CONCLUSION

ALT activity represents a strong and independent surrogate marker for mortality in community-dwelling elderly men.

Cardiovascular mortality attributable to high blood cholesterol in New Zealand

OBJECTIVE

To estimate mortality attributable to higher-than-optimal blood cholesterol in New Zealand in 1997, and the mortality burden that could be potentially avoided in 2011 if modest reductions in mean population blood cholesterol concentrations were achieved.

DESIGN

Comparative risk assessment methodology was used to estimate the attributable and avoidable mortality due to higher-than-optimal total blood cholesterol (> 3.8 mmol/L). Disease outcomes assessed were deaths from ischaemic heart disease (IHD) and ischaemic stroke.

RESULTS

Overall, higher-than-optimal blood cholesterol contributed to 4,721 deaths in New Zealand in 1997 (17% of all deaths). This included 4,096 IHD deaths (64%) and 625 ischaemic stroke deaths (38%). Modest reductions in mean population blood cholesterol concentrations (e.g. 0.1 mmol/L) could potentially prevent 300 deaths (261 IHD and 39 ischaemic stroke) each year from 2011.

CONCLUSIONS

Higher-than-optimal blood cholesterol concentrations are a leading cause of mortality in New Zealand. Modest reductions in blood cholesterol levels could have a major impact on population health within a decade.