Do statins impair cognition? A systematic review and meta-analysis of randomized controlled trials

The role of statin therapy in older adults: best practices and unmet challenges

INTRODUCTION

Cardiovascular disease (CVD) is associated with significant morbidity, functional decline, and mortality in older adults. The role of statins for primary CVD prevention in older adults remains unclear, largely due to systematic exclusion of these individuals in trials that inform current practice guidelines, leading to conflicting national and international practice recommendations for statin use for primary prevention of CVD in adults aged 75 and older.

AREAS COVERED

In this narrative review, we performed a literature review utilizing PubMed, and ultimately focus on seven major national and international guidelines of lipid lowering therapy. Through the lens of two clinical cases, we review physiologic changes in lipid metabolism with aging, discuss the relationship between cholesterol and cardiovascular events in older adults, examine the national and international guidelines and the available evidence informing these guidelines for statin use in primary prevention of CVD in older adults. Finally we review practical clinical considerations for drug monitoring and deprescribing in this population.

EXPERT OPINION

Guidelines for the use of statins for primary CVD prevention in older adults is conflicting. Collectively, evidence to date suggests statin therapy may be beneficial for primary CVD prevention in older adults free of life-limiting comorbidities. Randomized controlled trials are currently underway to address current evidence gaps.

Hypercholesterolemia and the Increased Risk of Vascular Dementia: a Cholesterol Perspective

PURPOSE OF REVIEW

Vascular dementia (VaD) is the second most prevalent type of dementia after Alzheimer's disease.Hypercholesterolemia may increase the risk of dementia, but the association between cholesterol and cognitive function is very complex. From the perspective of peripheral and brain cholesterol, we review the relationship between hypercholesterolemia and increased risk of VaD and how the use of lipid-lowering therapies affects cognition.

RECENT FINDINGS

Epidemiologic studies show since 1980, non-HDL-C levels of individuals has increased rapidly in Asian countries.The study has suggested that vascular risk factors increase the risk of VaD, such as disordered lipid metabolism. Dyslipidemia has been found to interact with chronic cerebral hypoperfusion to promote inflammation resulting in cognitive dysfunction in the brain.Hypercholesterolemia may be a risk factor for VaD. Inflammation could potentially serve as a link between hypercholesterolemia and VaD. Additionally, the potential impact of lipid-lowering therapy on cognitive function is also worth considering. Finding strategies to prevent and treat VaD is critical given the aging of the population to lessen the load on society. Currently, controlling underlying vascular risk factors is considered one of the most effective methods of preventing VaD. Understanding the relationship between abnormal cholesterol levels and VaD, as well as discovering potential serum biomarkers, is important for the early prevention and treatment of VaD.

In Vivo Simvastatin and Brain Radiation in a Model of HER2 + Inflammatory Breast Cancer Brain Metastasis

Purpose

Inhibiting HMG-CoA reductase with simvastatin prevents breast cancer metastases in preclinical models and radiosensitizes monolayer and stem-like IBC cell lines in vitro . Given the extensive use of simvastatin worldwide and its expected penetration into the brain, we examined whether regulating cholesterol with simvastatin affected IBC3 HER2+ brain metastases.

Methods and Materials

Breast cancer cell lines KPL4 and MDA-IBC3 were examined in vitro for DNA repair after radiation with or without statin treatment. Brain metastasis endpoints were examined in the MDA-IBC3 brain metastasis model after ex vivo exposure to lipoproteins and after tail vein injections with and without whole-brain radiotherapy (WBR) and oral statin exposure.

Results

Ex vivo preculture of MDA-IBC3 cells with very low-density lipoprotein (vLDL) enhanced the growth of colonized lesions in the brain in vivo compared with control or high-density lipoprotein (HDL), and concurrent oral simvastatin/ WBR reduced the incidence of micrometastatic lesions evaluated 10 days after WBR. However, statin, with or without WBR, did not reduce the incidence, burden, or number of macrometastatic brain lesions evaluated 5 weeks after WBR.

Conclusions

Although a role for cholesterol biosynthesis is demonstrated in DNA repair and response to whole brain radiation in this model, durable in vivo efficacy of concurrent whole brain irradiation and oral statin was not demonstrated.

Statin-related neurocognitive disorder: a real-world pharmacovigilance study based on the FDA adverse event reporting system

BACKGROUND

Concerns regarding statin-related neurocognitive disorders have emerged in recent years. However, previous studies have reported inconsistent results. We evaluated the association between statins and neurocognitive disorders using the FDA Adverse Event Reporting System (FAERS).

RESEARCH DESIGN AND METHODS

Data from 2004 to 2022 were obtained from the FAERS database. After deduplication and standardization of drug names, we extracted neurocognitive disorder event (NCDE) cases reported with statins as the suspected drugs. The significant association between statins and NCDE was evaluated using the reporting odds ratio (ROR) and information component.

RESULTS

In total, 6,959 NCDE cases with statins as the primary suspected drugs were identified. Signals were detected in pravastatin (ROR, 1.49; 95% CI: 1.32-1.67), atorvastatin (ROR, 1.39; 95% CI: 1.34-1.44), and simvastatin (ROR, 1.31; 95% CI: 1.25-1.38). Age-stratified analysis showed that (1) in the population aged 65 years and older, signals were detected for atorvastatin, simvastatin, rosuvastatin, pravastatin, lovastatin, fluvastatin, and pitavastatin; and (2) in populations under 65 years of age, signals were detected for atorvastatin, simvastatin, rosuvastatin, pravastatin, and lovastatin.

CONCLUSIONS

This study suggests a significant association between the NCDE and statins, including atorvastatin, simvastatin, and pravastatin. The intensity of the association increased with age.

Statin use moderates APOE's and CRP's associations with dementia and is associated with lesser dementia severity in ε4 carriers

INTRODUCTION

We tested the effect of statins on C-reactive protein (CRP) and apolipoprotein E (APOE)'s associations with dementia severity.

METHODS

A total of 1725 participants of the Alzheimer's Disease Neuroimaging Initiative (ADNI) were assigned from 12-month follow-up data into the following groups: (1) ε4 (-)/statin (-), (2) ε4 (-)/statin (+), (3) ε4 (+)/statin (-), and (4) ε4 (+)/statin (+). Dementia severity was assessed by a δ homolog: "dHABS." A mediation model was stratified on statin use and moderation effects tested by a chi-square difference.

RESULTS

Plasma CRP level decreased with ε4 allelic dose. Statins had no effect on the dHABS d-score in non-carriers but were associated with better scores in carriers. Treated carriers did not have more severe dementia than non-carriers. Statin use moderated the mutual adjusted effects of APOE and CRP. CRP was not a mediator of APOE's effect.

DISCUSSION

Statins may provide a protective effect on the dementia severity of ε4 carriers.

HIGHLIGHTS

δ is a dementia-specific phenotype related to general intelligence "g" and is assessed via a "d-score." Apolipoprotein E (APOE) and plasma C-reactive protein (CRP) are independently associated with δ. Plasma CRP decreases with ε4 allelic dose. Statins were associated with better (less demented) d-scores in ε4 carriers but had no effect in non-ε4 carriers. Treated ε4 carriers did not have more severe dementia than non-carriers. Statin use moderated the effects of APOE and CRP on δ. CRP was not a mediator of APOE's effect on δ.

Cognitive Safety is Largely Ignored in Clinical Drug Trials: A Study of Registered Study Protocols

BACKGROUND AND OBJECTIVE

The number of reports on suspected drug-induced memory impairment submitted to the US Food and Drug Administration increased 30-fold from 2000 to 2022. Drugs are the most common cause of reversible dementia. However, there is very little research on drug-induced cognitive impairment. The aim of this study was to investigate if and how an assessment of cognitive safety was included in recent, registered, controlled, clinical drug trials.

METHODS

The clinical trials registry ( www.

CLINICALTRIALS

gov ) was searched for randomized controlled clinical trials with available study protocols. After excluding irrelevant trials such as surgical procedures, local or short-term treatment, and dietary supplements, 803 trials were included in this study. The protocols were manually reviewed for information on if, and how, cognitive safety had been assessed. Trial drugs were categorized into those targeting the central nervous system or not, as well as older and newer drugs. Methods used for the assessment of cognitive function were categorized into questionnaires, screening instruments, and neuropsychological tests. If the trial results were published, we examined whether the publication contained any data on cognitive safety that had emerged from the trial.

RESULTS

The start dates of the screened trials ranged from 31 July, 2009, to 4 April, 2021. Out of the 803 trials, 52 (6.5%) actively assessed cognitive safety. The remaining trials relied solely on spontaneous reporting. Of 429 trials studying a new drug, 32 (7.5%) actively assessed cognitive safety. One hundred and fifty-eight trials examined drugs intended to, or known to have, pharmacological effects on the central nervous system. Of these, 21 (13.5%) assessed cognitive safety. Most of the trials that assessed cognitive safety used either crude screening tools or questionnaires.

CONCLUSIONS

Cognitive safety is largely ignored by recent controlled clinical trials. This applies even to trials assessing new drugs and trials assessing central nervous system drugs. There is an urgent need for drug manufacturers, regulatory authorities, and the medical profession to address the cognitive safety of drugs.

Statins and cognitive decline in patients with Alzheimer's and mixed dementia: a longitudinal registry-based cohort study

BACKGROUND

Disturbances in brain cholesterol homeostasis may be involved in the pathogenesis of Alzheimer's disease (AD). Lipid-lowering medications could interfere with neurodegenerative processes in AD through cholesterol metabolism or other mechanisms.

OBJECTIVE

To explore the association between the use of lipid-lowering medications and cognitive decline over time in a cohort of patients with AD or mixed dementia with indication for lipid-lowering treatment.

METHODS

A longitudinal cohort study using the Swedish Registry for Cognitive/Dementia Disorders, linked with other Swedish national registries. Cognitive trajectories evaluated with mini-mental state examination (MMSE) were compared between statin users and non-users, individual statin users, groups of statins and non-statin lipid-lowering medications using mixed-effect regression models with inverse probability of drop out weighting. A dose-response analysis included statin users compared to non-users.

RESULTS

Our cohort consisted of 15,586 patients with mean age of 79.5 years at diagnosis and a majority of women (59.2 %). A dose-response effect was demonstrated: taking one defined daily dose of statins on average was associated with 0.63 more MMSE points after 3 years compared to no use of statins (95% CI: 0.33;0.94). Simvastatin users showed 1.01 more MMSE points (95% CI: 0.06;1.97) after 3 years compared to atorvastatin users. Younger (< 79.5 years at index date) simvastatin users had 0.80 more MMSE points compared to younger atorvastatin users (95% CI: 0.05;1.55) after 3 years. Simvastatin users had 1.03 more MMSE points (95% CI: 0.26;1.80) compared to rosuvastatin users after 3 years. No differences regarding statin lipophilicity were observed. The results of sensitivity analysis restricted to incident users were not consistent.

CONCLUSIONS

Some patients with AD or mixed dementia with indication for lipid-lowering medication may benefit cognitively from statin treatment; however, further research is needed to clarify the findings of sensitivity analyses.

Lower serum cholesterol levels as a risk factor for critical illness polyneuropathy: a matched case-control study

Critical illness polyneuropathy (CIP) is a frequent and underdiagnosed phenomenon among intensive care unit patients. The lipophilic nature of neuronal synapses may result in the association of low serum cholesterol levels with a higher rate of CIP development. We aimed to investigate this issue in critically ill patients. All cases diagnosed with CIP in our tertiary care hospital between 2013 and 2017 were 1:1 matched with controls without the condition by age, sex, and ICD diagnoses. The main risk factors examined were the differences in change between initial and minimum serum total cholesterol levels, and minimum serum total cholesterol levels between matched pairs. Other predictors were serum markers of acute inflammation. We included 67 cases and 67 controls (134 critically ill patients, 49% female, 46% medical). Serum total cholesterol levels decreased more profoundly in cases than controls (median: -74 (IQR -115 to -24) vs. -39 (IQR -82 to -4), median difference: -28, 95% CI [-51, -5]), mg/dl). Minimum serum total cholesterol levels were lower in the cases (median difference: -24, 95% CI [-39, -9], mg/dl). We found significant median differences across matched pairs in maximum serum C-reactive protein (8.9, 95% CI [4.6, 13.2], mg/dl), minimum albumin (-4.2, 95% CI [-6.7, -1.7], g/l), decrease in albumin (-3.9, 95% CI [-7.6, -0.2], g/l), and lowest cholinesterase levels (-0.72, 95% CI [-1.05, -0.39], U/l). Subsequently, more pronounced decreases in serum total cholesterol levels and lower minimum total cholesterol levels during critical care unit hospitalizations may be a risk factor for CIP.

Neuronal γ-secretase regulates lipid metabolism, linking cholesterol to synaptic dysfunction in Alzheimer's disease

Presenilin mutations that alter γ-secretase activity cause familial Alzheimer's disease (AD), whereas ApoE4, an apolipoprotein for cholesterol transport, predisposes to sporadic AD. Both sporadic and familial AD feature synaptic dysfunction. Whether γ-secretase is involved in cholesterol metabolism and whether such involvement impacts synaptic function remains unknown. Here, we show that in human neurons, chronic pharmacological or genetic suppression of γ-secretase increases synapse numbers but decreases synaptic transmission by lowering the presynaptic release probability without altering dendritic or axonal arborizations. In search of a mechanism underlying these synaptic impairments, we discovered that chronic γ-secretase suppression robustly decreases cholesterol levels in neurons but not in glia, which in turn stimulates neuron-specific cholesterol-synthesis gene expression. Suppression of cholesterol levels by HMG-CoA reductase inhibitors (statins) impaired synaptic function similar to γ-secretase inhibition. Thus, γ-secretase enables synaptic function by maintaining cholesterol levels, whereas the chronic suppression of γ-secretase impairs synapses by lowering cholesterol levels.

Aggressive LDL-C Lowering and the Brain: Impact on Risk for Dementia and Hemorrhagic Stroke: A Scientific Statement From the American Heart Association

The objective of this scientific statement is to evaluate contemporary evidence that either supports or refutes the conclusion that aggressive low-density lipoprotein cholesterol lowering or lipid lowering exerts toxic effects on the brain, leading to cognitive impairment or dementia or hemorrhagic stroke. The writing group used literature reviews, references to published clinical and epidemiology studies, clinical and public health guidelines, authoritative statements, and expert opinion to summarize existing evidence and to identify gaps in current knowledge. Although some retrospective, case control, and prospective longitudinal studies suggest that statins and low-density lipoprotein cholesterol lowering are associated with cognitive impairment or dementia, the preponderance of observational studies and data from randomized trials do not support this conclusion. The risk of a hemorrhagic stroke associated with statin therapy in patients without a history of cerebrovascular disease is nonsignificant, and achieving very low levels of low-density lipoprotein cholesterol does not increase that risk. Data reflecting the risk of hemorrhagic stroke with lipid-lowering treatment among patients with a history of hemorrhagic stroke are not robust and require additional focused study.

PCSK9 inhibitor, ezetimibe, and bempedoic acid: Evidence-based therapies for statin-intolerant patients

Statins are first-line therapy for treating dyslipidemia because of their low-density lipoprotein cholesterol (LDL-C) lowering efficacy, superior event-reduction data and unrivaled cost-effectiveness. Yet, many people are intolerant of statins, whether due to true adverse events or the nocebo effect, so within one year about two-thirds of primary prevention patients and one-third of secondary prevention patients are no longer taking their prescription. Statins still dominate this landscape, but other agents, often used in combination, potently reduce LDL-C levels, regress atherosclerosis and lower risk of major adverse cardiovascular events (MACE). Ezetimibe lowers LDL-C by reducing intestinal absorption of cholesterol. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) lower LDL-C by increasing the number and durability of hepatic LDL receptors. Bempedoic acid reduces hepatic cholesterol synthesis. Ezetimibe, PCSK9i and bempedoic are evidence-based, non-statin therapies that synergistically lower LDL-C and reduce risk of MACE; they also have benign side-effect profiles and are generally well tolerated.

The Comparative Effectiveness of Monotherapy and Combination Therapies: Impact of Angiotensin Receptor Blockers on the Onset of Alzheimer's Disease

Background

The criteria for use of Alzheimer's disease (AD) drug Leqembi recommended by the Department of Veterans Affairs (VA) include patients aged 65 years or older with mild cognitive impairment (MCI) or mild AD. Comorbidities that include hypertension, hyperlipidemia, and diabetes are common among these patients.

Objectives

Our objective is to investigate the comparative effectiveness of the administration of one, two, or three medications belonging to the categories of angiotensin receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs), Beta Blockers, Statins, and Metformin, for their potential to delay the clinical onset of AD and provide a window of opportunity for therapeutic intervention.

Design

Retrospective matched case-control study.

Setting

Data from the Department of Veterans Affairs national corporate data warehouse.

Participants

We conducted an analysis of 122,351 participants (13,611 with AD and 108,740 without AD), aged 65-89, who began at least one of the prescribed medication classes under investigation between October 1998 and April 2018.

Measurements

We utilized Cox proportional hazard regressions, both with and without propensity score weighting, to estimate hazard ratios (HR) associated with the use of different medication combinations for the pre-symptomatic survival time of AD onset. Additionally, we employed a supervised machine learning algorithm (random forest) to assess the relative importance of various therapies in predicting the occurrence of AD.

Result

Adding Metformin to the combination of ACEI+Beta Blocker (HR = 0.56, 95% CI (0.41, 0.77)) reduced the risk of AD onset compared to ACEI monotherapy alone (HR = 0.91, (0.85, 0.98)), Beta Blocker monotherapy (HR = 0.86, 95% CI (0.80, 0.92)), or combined ACEI+Beta Blocker (HR=0.85, 95%CI (0.77, 0.94)), when statin prescribers were used as a reference. Prescriptions of ARB alone or the combination of ARB with Beta Blocker showed an association with a lower risk of AD onset.

Conclusion

Selected medications for the treatment of multiple chronic conditions among elderly individuals with hypertension, hyperlipidemia, and diabetes as monotherapy or combination therapies lengthen the pre-symptomatic period before the onset of AD.

Pragmatic evaluation of events and benefits of lipid lowering in older adults (PREVENTABLE): Trial design and rationale

Whether initiation of statins could increase survival free of dementia and disability in adults aged ≥75 years is unknown. PREVENTABLE, a double-blind, placebo-controlled randomized pragmatic clinical trial, will compare high-intensity statin therapy (atorvastatin 40 mg) with placebo in 20,000 community-dwelling adults aged ≥75 years without cardiovascular disease, disability, or dementia at baseline. Exclusion criteria include statin use in the prior year or for >5 years and inability to take a statin. Potential participants are identified using computable phenotypes derived from the electronic health record and local referrals from the community. Participants will undergo baseline cognitive testing, with physical testing and a blinded lipid panel if feasible. Cognitive testing and disability screening will be conducted annually. Multiple data sources will be queried for cardiovascular events, dementia, and disability; survival is site-reported and supplemented by a National Death Index search. The primary outcome is survival free of new dementia or persisting disability. Co-secondary outcomes are a composite of cardiovascular death, hospitalization for unstable angina or myocardial infarction, heart failure, stroke, or coronary revascularization; and a composite of mild cognitive impairment or dementia. Ancillary studies will offer mechanistic insights into the effects of statins on key outcomes. Biorepository samples are obtained and stored for future study. These results will inform the benefit of statins for increasing survival free of dementia and disability among older adults. This is a pioneering pragmatic study testing important questions with low participant burden to align with the needs of the growing population of older adults.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) in the central nervous system

The gene encoding proprotein convertase subtilisin/kexin type 9 (PCSK9) and its protein product have been widely studied for their role in cholesterol and lipid metabolism. PCSK9 increases the rate of metabolic degradation of low-density lipoprotein receptors, preventing the diffusion of low-density lipoprotein (LDL) from plasma into cells and contributes to high lipoprotein-bound cholesterol levels in the plasma. While most research has focused on the regulation and disease relevance of PCSK9 to the cardiovascular system and lipid metabolism, there is a growing body of evidence that PCSK9 plays a crucial role in pathogenic processes in other organ systems, including the central nervous system. PCSK9's impact on the brain is not yet fully understood, though several recent studies have sought to illuminate its impact on various neurodegenerative and psychiatric disorders, as well as its connection with ischemic stroke. Cerebral PCSK9 expression is low but is highly upregulated during disease states. Among others, PCSK9 is known to play a role in neurogenesis, neural cell differentiation, central LDL receptor metabolism, neural cell apoptosis, neuroinflammation, Alzheimer's Disease, Alcohol Use Disorder, and stroke. The PCSK9 gene contains several polymorphisms, including both gain-of-function and loss-of-function mutations which profoundly impact normal PCSK9 signaling and cholesterol metabolism. Gain-of-function mutations lead to persistent hypercholesterolemia and poor health outcomes, while loss-of-function mutations generally lead to hypocholesterolemia and may serve as a protective factor against diseases of the liver, cardiovascular system, and central nervous system. Recent genomic studies have sought to identify the end-organ effects of such mutations and continue to identify evidence of a much broader role for PCSK9 in extrahepatic organ systems. Despite this, there remain large gaps in our understanding of PCSK9, its regulation, and its effects on disease risk outside the liver. This review, which incorporates data from a wide range of scientific disciplines and experimental paradigms, is intended to describe PCSK9's role in the central nervous system as it relates to cerebral disease and neuropsychiatric disorders, and to examine the clinical potential of PCSK9 inhibitors and genetic variation in the PCSK9 gene on disease outcomes, including neurological and neuropsychiatric disease.

Atorvastatin differentially regulates the interactions of cocaine and amphetamine with dopamine transporters

The function of the dopamine transporter (DAT) is regulated by membrane cholesterol content. A direct, acute removal of membrane cholesterol by methyl-β-cyclodextrin (MβCD) has been shown to reduce dopamine (DA) uptake and release mediated by the DAT. This is of particular interest because a few widely prescribed statins that lower peripheral cholesterol levels are blood-brain barrier (BBB) penetrants, and therefore could alter DAT function through brain cholesterol modulation. The goal of this study was to investigate the effects of prolonged atorvastatin treatment (24 h) on DAT function in neuroblastoma 2A cells stably expressing DAT. We found that atorvastatin treatment effectively lowered membrane cholesterol content in a concentration-dependent manner. Moreover, atorvastatin treatment markedly reduced DA uptake and abolished cocaine inhibition of DA uptake, independent of surface DAT levels. These deficits induced by atorvastatin treatment were reversed by cholesterol replenishment. However, atorvastatin treatment did not change amphetamine (AMPH)-induced DA efflux. This is in contrast to a small but significant reduction in DA efflux induced by acute depletion of membrane cholesterol using MβCD. This discrepancy may involve differential changes in membrane lipid composition resulting from chronic and acute cholesterol depletion. Our data suggest that the outward-facing conformation of DAT, which favors the binding of DAT blockers such as cocaine, is more sensitive to atorvastatin-induced cholesterol depletion than the inward-facing conformation, which favors the binding of DAT substrates such as AMPH. Our study on statin-DAT interactions may have clinical implications in our understanding of neurological side effects associated with chronic use of BBB penetrant statins.

Cerebral Small Vessel Disease-Related Dementia: More Questions Than Answers

Cerebral small vessel disease (CSVD) has emerged as a common factor driving age-dependent diseases, including stroke and dementia. CSVD-related dementia will affect a growing fraction of the aging population, requiring improved recognition, understanding, and treatments. This review describes evolving criteria and imaging biomarkers for the diagnosis of CSVD-related dementia. We describe diagnostic challenges, particularly in the context of mixed pathologies and the absence of highly effective biomarkers for CSVD-related dementia. We review evidence regarding CSVD as a risk factor for developing neurodegenerative disease and potential mechanisms by which CSVD leads to progressive brain injury. Finally, we summarize recent studies on the effects of major classes of cardiovascular medicines relevant to CSVD-related cognitive impairment. Although many key questions remain, the increased attention to CSVD has resulted in a sharper vision for what will be needed to meet the upcoming challenges imposed by this disease.

Side effects of statins: from pathophysiology and epidemiology to diagnostic and therapeutic implications

Treatment with statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, has proven beneficial preventive effects on cardiovascular events. However, discontinuation due to intolerance and non-adherence remain two of the major gaps in both primary and secondary prevention. This leads many patients with high-risk of atherosclerotic cardiovascular disease (ASCVD) to be inadequately treated or not to achieve target lipid level goals, and as consequence they undergo an increased risk of cardiovascular events. The aim of this review is thus to give an overview of the reasons for discontinuation and on the possible mechanisms behind them. Although statins, as a class, are generally safe, they are associated with an increased risk of diabetes mellitus and hepatic transaminase elevations. Incidence of cataracts or cognitive dysfunction and others presented in the literature (e.g. proteinuria and haematuria) have been never confirmed to have a causal link. Conversely, debated remains the effect on myalgia. Muscle side effects are the most commonly reported, although myalgia is still believed by some to be the result of a nocebo/drucebo effect. Concerning mechanisms behind muscular side effects, no clear conclusions have been reached. Thus, if on one side it is important to identify individuals either at higher risk to develop a side effect, or with confirmed risk factors and conditions of statin intolerance, on the other side alternative strategies should be identified to avoid an increased ASCVD risk.

Management of Acute Coronary Syndrome in the Older Adult Population: A Scientific Statement From the American Heart Association

Diagnostic and therapeutic advances during the past decades have substantially improved health outcomes for patients with acute coronary syndrome. Both age-related physiological changes and accumulated cardiovascular risk factors increase the susceptibility to acute coronary syndrome over a lifetime. Compared with younger patients, outcomes for acute coronary syndrome in the large and growing demographic of older adults are relatively worse. Increased atherosclerotic plaque burden and complexity of anatomic disease, compounded by age-related cardiovascular and noncardiovascular comorbid conditions, contribute to the worse prognosis observed in older individuals. Geriatric syndromes, including frailty, multimorbidity, impaired cognitive and physical function, polypharmacy, and other complexities of care, can undermine the therapeutic efficacy of guidelines-based treatments and the resiliency of older adults to survive and recover, as well. In this American Heart Association scientific statement, we (1) review age-related physiological changes that predispose to acute coronary syndrome and management complexity; (2) describe the influence of commonly encountered geriatric syndromes on cardiovascular disease outcomes; and (3) recommend age-appropriate and guideline-concordant revascularization and acute coronary syndrome management strategies, including transitions of care, the use of cardiac rehabilitation, palliative care services, and holistic approaches. The primacy of individualized risk assessment and patient-centered care decision-making is highlighted throughout.

Primary prevention statin therapy in older adults

PURPOSE OF REVIEW

The purpose of this review is to assess the evidence for primary prevention statin treatment in older adults, within the context of the most recent guideline recommendations, while also highlighting important considerations for shared decision-making.

RECENT FINDINGS

As the average lifespan increases and the older adult population grows, the opportunity for prevention of morbidity and mortality from cardiovascular disease is magnified. Randomized trials and meta-analyses have demonstrated a clear benefit for primary prevention statin use through age 75, with uncertainty beyond that age. Despite these data supporting their use, current guidelines conflict in their statin treatment recommendations in those aged 70-75 years. Reflecting the paucity of evidence, the same guidelines are equivocal around primary prevention statins in those beyond age 75. Two large ongoing randomized trials (STAREE and PREVENTABLE) will provide additional insights into the treatment benefits and risks of primary prevention statins in the older adult population. In the meantime, a holistic approach in treatment decisions remains paramount for older patients.

SUMMARY

The benefits of primary prevention statin treatment are apparent through age 75, which is reflected in the current ACC/AHA and USPSTF recommendations. Ongoing trials will clarify the utility in those beyond age 75.

Long-term atorvastatin improves cognitive decline by regulating gut function in naturally ageing rats

Background

Statins have been widely used to prevent cardiovascular disease in middle-aged and elderly populations; however, the effect of long-term treatment on cognitive function is controversial. To simulate clinical conditions, middle-aged rats were given atorvastatin for 9 consecutive months to investigate the effect on natural cognitive decline and the possible mechanisms.

Results

The results showed that compared with the control group, long-term atorvastatin treatment naturally improved cognitive decline. Furthermore, long-term treatment regulated intestinal retinoic acid (RA) metabolism and storage by altering retinol dehydrogenase 7 (Rdh7) expression in the intestine, while RA metabolism affected the proliferation of intestinal Treg cells and inhibited IL-17+γδ T-cell function. In addition, long-term atorvastatin increased intestinal flora richness and decreased IL-17 expression in hippocampal tissue.

Conclusion

Collectively, these findings provide the first evidence that long-term atorvastatin intervention may prevent cognitive decline in naturally ageing rats by inhibiting neuroinflammation via the gut-brain axis.

Statins Use in Alzheimer Disease: Bane or Boon from Frantic Search and Narrative Review

Alzheimer’s disease (AD) was used to describe pre-senile dementia to differentiate it from senile dementia, which develops in the adult age group of more than 65 years. AD is characterized by the deposition of amyloid beta (Aβ) plaque and tau-neurofibrillary tangles (TNTs) in the brain. The neuropathological changes in AD are related to the deposition of amyloid plaques, neurofibrillary tangles, and progression of neuroinflammation, neuronal mitochondrial dysfunction, autophagy dysfunction, and cholinergic synaptic dysfunction. Statins are one of the main cornerstone drugs for the management of cardiovascular disorders regardless of dyslipidemia status. Increasing the use of statins, mainly in the elderly groups for primary and secondary prevention of cardiovascular diseases, may affect their cognitive functions. Extensive and prolonged use of statins may affect cognitive functions in healthy subjects and dementia patients. Statins-induced cognitive impairments in both patients and health providers had been reported according to the post-marketing survey. This survey depends mainly on sporadic cases, and no cognitive measures were used. Evidence from prospective and observational studies gives no robust conclusion regarding the beneficial or detrimental effects of statins on cognitive functions in AD patients. Therefore, this study is a narrative review aimed with evidences to the beneficial, detrimental, and neutral effects of statins on AD.

Statins, Enzyme CoQ10 Supplement Use, and Cognitive Functioning

OBJECTIVE

The current study assessed the effects of statin and CoQ₁₀ supplement use on changes in cognitive functioning in the Wisconsin Registry for Alzheimer's Prevention study.

METHODS

1,573 subjects were administered medical histories, the Mini-Mental State Examination (MMSE), Rey Auditory Verbal Learning Test (RAVLT), Wechsler Memory Scale, Logical Memory subtest, and the Trail Making Test, Parts A (TMT-A) and B (TMT-B) 3-4 times over 5-10 years.

RESULTS

Linear mixed models did not yield significant effects for statin or CoQ₁₀ supplement use on changes in mental status, learning and memory, psychomotor speed, and cognitive flexibility.

CONCLUSIONS

Statin and/or CoQ₁₀ supplement use was not associated with neuropsychological test performance in the Wisconsin Registry for Alzheimer's Prevention study.

Cholesterol as a key player in amyloid β-mediated toxicity in Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative disorder that is one of the most devastating and widespread diseases worldwide, mainly affecting the aging population. One of the key factors contributing to AD-related neurotoxicity is the production and aggregation of amyloid β (Aβ). Many studies have shown the ability of Aβ to bind to the cell membrane and disrupt its structure, leading to cell death. Because amyloid damage affects different parts of the brain differently, it seems likely that not only Aβ but also the nature of the membrane interface with which the amyloid interacts, helps determine the final neurotoxic effect. Because cholesterol is the dominant component of the plasma membrane, it plays an important role in Aβ-induced toxicity. Elevated cholesterol levels and their regulation by statins have been shown to be important factors influencing the progression of neurodegeneration. However, data from many studies have shown that cholesterol has both neuroprotective and aggravating effects in relation to the development of AD. In this review, we attempt to summarize recent findings on the role of cholesterol in Aβ toxicity mediated by membrane binding in the pathogenesis of AD and to consider it in the broader context of the lipid composition of cell membranes.

Statins in High Cardiovascular Risk Patients: Do Comorbidities and Characteristics Matter?

Atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality are decreasing in high-income countries, but ASCVD remains the leading cause of morbidity and mortality in high-income countries. Over the past few decades, major risk factors for ASCVD, including LDL cholesterol (LDL-C), have been identified. Statins are the drug of choice for patients at increased risk of ASCVD and remain one of the most commonly used and effective drugs for reducing LDL cholesterol and the risk of mortality and coronary artery disease in high-risk groups. Unfortunately, doctors tend to under-prescribe or under-dose these drugs, mostly out of fear of side effects. The latest guidelines emphasize that treatment intensity should increase with increasing cardiovascular risk and that the decision to initiate intervention remains a matter of individual consideration and shared decision-making. The purpose of this review was to analyze the indications for initiation or continuation of statin therapy in different categories of patient with high cardiovascular risk, considering their complexity and comorbidities in order to personalize treatment.

No association between APOE genotype and lipid lowering with cognitive function in a randomized controlled trial of evolocumab

APOE encodes a cholesterol transporter, and the ε4 allele is associated with higher circulating cholesterol levels, ß-amyloid burden, and risk of Alzheimer's disease. Prior studies demonstrated no significant differences in objective or subjective cognitive function for patients receiving the PCSK9 inhibitor evolocumab vs. placebo added to statin therapy. There is some evidence that cholesterol-lowering medications may confer greater cognitive benefits in APOE ε4 carriers. Thus, the purpose of this study was to determine whether APOE genotype moderates the relationships between evolocumab use and cognitive function. APOE-genotyped patients (N = 13,481; 28% ε4 carriers) from FOURIER, a randomized, placebo-controlled trial of evolocumab added to statin therapy in patients with stable atherosclerotic cardiovascular disease followed for a median of 2.2 years, completed the Everyday Cognition Scale (ECog) to self-report cognitive changes from the end of the trial compared to its beginning; a subset (N = 835) underwent objective cognitive testing using the Cambridge Neuropsychological Test Automated Battery as part of the EBBINGHAUS trial. There was a dose-dependent relationship between APOE ε4 genotype and patient-reported memory decline on the ECog in the placebo arm (p = .003 for trend across genotypes; ε4/ε4 carriers vs. non-carriers: OR = 1.46, 95% CI [1.03, 2.08]) but not in the evolocumab arm (p = .50, OR = 1.18, 95% CI [.83,1.66]). However, the genotype by treatment interaction was not significant (p = .30). In the subset of participants who underwent objective cognitive testing with the CANTAB, APOE genotype did not significantly modify the relationship between treatment arm and CANTAB performance after adjustment for demographic and medical covariates, (p's>.05). Although analyses were limited by the low population frequency of the ε4/ε4 genotype, this supports the cognitive safety of evolocumab among ε4 carriers, guiding future research on possible benefits of cholesterol-lowering medications in people at genetic risk for Alzheimer's disease.

Molecular targets of statins and their potential side effects: Not all the glitter is gold

Statins are a class of drugs widely used worldwide to manage hypercholesterolemia and the prevention of secondary heart attacks. Currently, available statins vary in terms of their pharmacokinetic and pharmacodynamic profiles. Although the primary target of statins is the inhibition of HMG-CoA reductase (HMGR), the rate-limiting enzyme in cholesterol biosynthesis, statins exhibit many pleiotropic effects downstream of the mevalonate pathway. These pleiotropic effects include the ability to reduce myocardial fibrosis, pathologic cardiac disease states, hypertension, promote bone differentiation, anti-inflammatory, and antitumor effects through multiple mechanisms. Although these pleiotropic effects of statins may be a cause for enthusiasm, there are many adverse effects that, for the most part, are unappreciated and need to be highlighted. These adverse effects include myopathy, new-onset type 2 diabetes, renal and hepatic dysfunction. Although these adverse effects may be relatively uncommon, considering the number of people worldwide who use statins daily, the actual number of people affected becomes quite large. Also, co-administration of statins with several other medications, herbal agents, and foods, which interact through common enzymatic pathways, can have untoward clinical consequences. In this review, we address these concerns.

Research advances in the influence of lipid metabolism on cognitive impairment

Cognitive impairment (CI) is a mental disorder related to cognition and understanding, which is mainly categorized into mild CI and senile dementia. This disease is associated with multiple factors, such as chronic brain injury, aging, chronic systemic disease, mental state, and psychological factors. However, the pathological mechanism of CI remains unclear; it is usually associated with such underlying diseases as diabetes and hyperlipidemia. It has been demonstrated that abundant lipid metabolism indexes in the human body are closely related to CI, including total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, apolipoprotein, and so forth. As a crucial risk factor for CI, hyperlipidemia is of great significance in the occurrence and development of CI. However, the specific correlation between dyslipidemia and CI is still not fully elucidated. Besides, the efficacy of lipid-lowering drugs in the prophylaxis and treatment of CI has not been clarified. In this study, relevant advances in the influence of lipid metabolism disorders in CI will be reviewed, in an attempt to explore the effect of mediating blood lipid levels on the prophylaxis and treatment of CI, thus providing a reference for its clinical management.

Exploring the Genetic Associations Between the Use of Statins and Alzheimer's Disease

Objective

Alzheimer's disease (AD) is the most common cause of dementia. The statins have shown beneficial effects on cognitive functions and reduced the risk of dementia development. However, the exact mechanisms of statin effects in AD are not yet fully understood. In this study, we aimed to explore the underlying mechanisms of statin on AD.

Methods

We downloaded AD blood dataset (GSE63060) and statin-related blood gene expression dataset (GSE86216). Then we performed gene expression analysis of each dataset and compared blood gene expressions between AD patients and statin-treated patients. Then, we downloaded mouse embryonic neural stem cell dataset (GSE111945) and performed gene expression analysis.

Results

From the human blood dataset, we identified upregulated/downregulated genes in AD patients and statin-treated patients. Some of the upregulated genes (AEN, MBTPS1, ABCG1) in the blood of AD patients are downregulated in statin-treated patients. Several downregulated genes (FGL2, HMGCS1, PSME2, SRSF3, and ATG3) are upregulated in statin-treated patients. Gene set enrichment analysis using mouse stem cell dataset revealed a significant relationship of Kyoto Encyclopedia of Genes and Genomes-defined pathway of AD in statin-treated neural stem cells compared to vehicle-treated neural stem cells (normalized enrichment score: −2.24 in male and −1.6 in female).

Conclusion

These gene expression analyses from human blood and mouse neural stem cell demonstrate the important clues on the molecular mechanisms of impacts of statin on AD disease. Further studies are needed to investigate the exact role of candidate genes and pathways suggested in our AD pathogenesis study.

Statin Therapy in Very Old Patients: Lights and Shadows

Atherosclerotic cardiovascular diseases (ASCVD) are the leading cause of death worldwide. High levels of total cholesterol—and of low-density lipoprotein cholesterol in particular—are one of the main risk factors associated with ASCVD. Statins are first-line treatment for hypercholesterolemia and have been proven to reduce major vascular events in adults with and without underlying ASCVD. Findings in the literature show that statins reduce coronary and cerebrovascular morbidity and mortality in middle-aged people, but their benefits in older adults are not as well-established, especially in primary prevention. Furthermore, many particularities must be considered regarding their use in old subjects, such as age-related changes in pharmacokinetics and pharmacodynamics, comorbidities, polypharmacy, and frailty, which decrease the safety and efficacy of statins in this population. Myopathy and a possible higher risk of falling along with cognitive decline are classic concerns for physicians when considering statin use in the very old. Additionally, some studies suggest that the relative risk for coronary events and cardiovascular mortality associated with high levels of cholesterol decreases after age 70, making the role of statins unclear. On the other hand, ASCVD are one of the most important causes of disability in old subjects, so cardiovascular prevention is of particular interest in this population in order to preserve functional status. This review aims to gather the current available evidence on the efficacy and safety of statin use in very old patients in both primary and secondary prevention.

Lipophilic vs. hydrophilic statins and psychiatric hospitalizations and emergency room visits in US Veterans with schizophrenia and bipolar disorder

Objective –

Psychiatric hospitalizations and emergency department (ED) visits are costly, stigmatizing, and often ineffective. Given the immune and kynurenine activation in bipolar disorder (BD) and schizophrenia, as well as the immune-modulatory effects of statins, we aimed to compare the relative risk (RRs) of psychiatric hospitalizations and ED visits between individuals prescribed lipophilic vs. hydrophilic statins vs. no statins. We hypothesized (a) reduced rates of hospitalization and ER utilization with statins versus no statins and (b) differences in outcomes between statins, as lipophilia increases the capability to penetrate the blood–brain barrier with potentially beneficial neuroimmune, antioxidant, neuroprotective, neurotrophic, and endothelial stabilizing effects, and, in contrast, potentially detrimental decreases in brain cholesterol concentrations leading to serotoninergic dysfunction, changes in membrane lipid composition, thus affecting ion channels and receptors.

Methods –

We used VA service utilization data from October 1, 2010 to September 30, 2015. The RRs for psychiatric hospitalization and ED visits, were estimated using robust Poisson regression analyses. The number of individuals analyzed was 683,129.

Results –

Individuals with schizophrenia and BD who received prescriptions for either lipophilic or hydrophilic statins had a lower RR of psychiatric hospitalization or ED visits relative to nonstatin controls. Hydrophilic statins were significantly associated with lower RRs of psychiatric hospitalization but not of ED visits, compared to lipophilic statins.

Conclusion –

The reduction in psychiatric hospitalizations in statin users (vs. nonusers) should be interpreted cautiously, as it carries a high risk of confounding by indication. While the lower RR of psychiatric hospitalizations in hydrophilic statins relative to the lipophilic statins is relatively bias free, the finding bears replication in a specifically designed study. If replicated, important clinical implications for personalizing statin treatment in patients with mental illness, investigating add-on statins for improved therapeutic control, and mechanistic exploration for identifying new treatment targets are natural next steps.

Update on Statin Treatment in Patients with Neuropsychiatric Disorders

Statins are widely accepted as first-choice agents for the prevention of lipid-related cardiovascular diseases. These drugs have both anti-inflammatory and anti-oxidant properties, which may also make them effective as potential treatment marked by perturbations in these pathways, such as some neuropsychiatric disorders. In this narrative review, we have investigated the effects of statin therapy in individuals suffering from major depressive disorder (MDD), schizophrenia, anxiety, obsessive-compulsive disorder (OCD), bipolar disorder (BD), delirium, and autism spectrum disorders using a broad online search of electronic databases. We also explored the adverse effects of these drugs to obtain insights into the benefits and risks associated with their use in the treatment of these disorders. Lipophilic statins (including simvastatin) because of better brain penetrance may have greater protective effects against MDD and schizophrenia. The significant positive effects of statins in the treatment of anxiety disorders without any serious adverse side effects were shown in numerous studies. In OCD, BD, and delirium, limitations, and contradictions in the available data make it difficult to draw conclusions on any positive effect of statins. The positive effects of simvastatin in autism disorders have been evaluated in only a small number of clinical trials. Although some studies showed positive effect of statins in some neuropsychiatric disorders, further prospective studies are needed to confirm this and define the most effective doses and treatment durations.

Statin use and risk of dementia or Alzheimer's disease: a systematic review and meta-analysis of observational studies

AIMS

As the potential impact of statins on cognitive decline and dementia is still debated, we conducted a meta-analysis of observational studies to examine the effect of statin use on the risk of Alzheimer's disease (AD) and dementia.

METHODS AND RESULTS

PubMed, Cochrane, and EMBASE were searched since inception to January 2021. Inclusion criteria were: (i) cohort or case-control studies; (ii) statin users compared to non-users; and (iii) AD and/or dementia risk as outcome. Estimates from original studies were pooled using restricted maximum-likelihood random-effect model. Measure of effects were reported as odds ratio (OR) and 95% confidence intervals (CIs). In the pooled analyses, statins were associated with a decreased risk of dementia [36 studies, OR 0.80 (CI 0.75-0.86)] and of AD [21 studies, OR 0.68 (CI 0.56-0.81)]. In the stratified analysis by sex, no difference was observed in the risk reduction of dementia between men [OR 0.86 (CI 0.81-0.92)] and women [OR 0.86 (CI 0.81-0.92)]. Similar risks were observed for lipophilic and hydrophilic statins for both dementia and AD, while high-potency statins showed a 20% reduction of dementia risk compared with a 16% risk reduction associated with low-potency statins, suggesting a greater efficacy of the former, although a borderline statistical significance (P = 0.05) for the heterogeneity between estimates.

CONCLUSION

These results confirm the absence of a neurocognitive risk associated with statin treatment and suggest a potential favourable role of statins. Randomized clinical trials with an ad hoc design are needed to explore this potential neuroprotective effect.

Genetic mutations of APOEε4 carriers in cardiovascular patients lead to the development of insulin resistance and risk of Alzheimer's disease

Type 2 diabetes mellitus and Alzheimer's disease (AD), both are chronic and progressive diseases. Many cardiovascular and genetic risk factors are considered responsible for the development of AD and diabetes mellitus (DM). Genetic risk factor such as apolipoprotein E (APOE) plays a critical role in the progression of AD. Specifically, APOEε4 is genetically the strongest isoform associated with neuronal insulin deficiency, altered lipid homeostasis, and metabolism, decreased glucose uptake, impaired gray matter volume, and cerebrovascular functions. In this article, we have summarized the mechanisms of cardiovascular disturbances associated with AD and DM, impact of amyloid-β aggregation, and neurofibrillary tangles formation in AD. Moreover, cardiovascular risk factors leading to insulin resistance (IR) and amyloid-β aggregation are highlighted along with the effects of APOE risk alleles on cerebral, lipid, and cholesterol metabolism leading to CVD-mediated IR. Correspondingly, the contribution of IR, genetic and cardiovascular risk factors in amyloid-β aggregation, which may lead to the late onset of AD and DM, has been also discussed. In short, IR is related to significantly lower cerebral glucose metabolism, which sequentially forecasts poorer memory performance. Hence, there will be more chances for neural glucose intolerance and impairment of cognitive function in cardiac patients, particularly APOEε4 carriers having IR. Hence, this review provides a better understanding of the corresponding crosstalk among different pathways. This will help to investigate the rational application of preventive measures against IR and cognitive dysfunction, specifically in APOEε4 carriers' cardio-metabolic patients.

Implementation of Pharmacist Reviews to Screen for Potentially Inappropriate Medications in Patients With Cognitive Impairment

Objective: To describe two pharmacist-led initiatives aimed to reduce potentially inappropriate medication (PIM) use in community-dwelling patients with dementia or cognitive impairment. Design: Retrospective, descriptive analysis of two clinical initiatives. Setting: Academic geriatric primary care clinics. Participants: Patients were included if they received a Memory Clinic pharmacist review May 1, 2017, to December 31, 2019, or a Living with Dementia (LWD) program pharmacist review November 15, 2018 to December 31, 2019 with provider follow-up within 6 months. Interventions: Both initiatives involved medication review by a clinical pharmacist to identify and make recommendations regarding medications that may contribute to cognitive impairment. The Memory Clinic served patients with concerns of cognitive impairment; whereas, the LWD program enrolled patients with an established diagnosis of dementia. Main Outcome Measure: Number of PIMs that could negatively impact cognition within each cohort. Additionally, 6-month implementation rates were analyzed for actionable pharmacist recommendations. RESULTS: Memory Clinic patients (n = 110) were taking an average of 2.4 PIMs; whereas, LWD patients (n = 40) were taking an average of 1.5 PIMs. Six-month implementation rates for all actionable pharmacist recommendations were 61.0% for the Memory Clinic and 42.4% for the LWD program. Specifically evaluating deprescribing recommendations, the 6-month PIM discontinuation rate was 63.6% for the Memory Clinic group and 60.0% for the LWD group. Conclusion: Pharmacists routinely identified PIMs during medication reviews, which led to successful recommendation implementation throughout multiple stages of cognitive decline. Both programs will continue to be adapted to ensure maximal impact.

Association of Glycemia, Lipids, and Blood Pressure With Cognitive Performance in People With Type 2 Diabetes in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

Type 2 diabetes is a risk factor for cognitive impairment. We examined the relation of glycemia, lipids, blood pressure (BP), hypertension history, and statin use with cognition in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE).

RESEARCH DESIGN AND METHODS

Cross-sectional analyses from GRADE at baseline examined the association of glycemia (hemoglobin A1c [HbA1c]), LDL, systolic BP (SBP) and diastolic BP (DBP), hypertension history, and statin use with cognition assessed by the Spanish English Verbal Learning Test, letter and animal fluency tests, and Digit Symbol Substitution Test (DSST).

RESULTS

Among 5,047 GRADE participants, 5,018 (99.4%) completed cognitive assessments. Their mean age was 56.7 ± 10.0 years, and 36.4% were women. Mean diabetes duration was 4.0 ± 2.7 years. HbA1c was not related to cognition. Higher LDL was related to modestly worse DSST scores, whereas statin use was related to modestly better DSST scores. SBP between 120 and 139 mmHg and DBP between 80 and 89 mmHg were related to modestly better DSST scores. Hypertension history was not related to cognition.

CONCLUSIONS

In people with type 2 diabetes of a mean duration of <5 years, lower LDL and statin use were related to modestly better executive cognitive function. SBP levels in the range of 120-139 mmHg and DBP levels in the range of 80-89 mmHg, but not lower levels, were related to modestly better executive function. These differences may not be clinically significant.

An impact of lipid profile and lipid lowering drugs on ≥70 year olds of an upper socioeconomic class: a retrospective cohort study

BACKGROUND

Life expectancy has greatly increased, generating an improvement in screening programs for disease prevention, lifesaving drugs and medical devices. The impact of lowering low-density lipoprotein cholesterol (LDL-C) in the very elderly is not well-established. Our aim was to explore the association of LDL-C, high density lipoprotein cholesterol (HDL-C) and lipid lowering drugs (LLDs) on cognitive decline, malignancies and overall survival.

METHODS

This was a retrospective cohort study. Our study comprised 1498 (72.7%) males and 561 (27.3%) females, aged ≥70 who had attended the Institute for Medical Screening (IMS), Sheba Medical Center, Israel at least twice during 2013-2019. Data were obtained from the computerized database of the IMS. A manual quality control to identify potential discrepancies was performed.

RESULTS

Overall, 6.3% of the subjects treated with LLDs (95/1421) versus 4.2% not treated (28/638), cognitively declined during the study years. No statistically significant effects of LDL-C, HDL-C and LLDs on cognitive decline were observed after correcting for age, prior stroke and other vascular risk factors. With regard to cancer, after adjusting for confounders and multiple inferences, no definite relationships were found.

CONCLUSIONS

This analysis of an elderly, high socioeconomic status cohort suggests several relationships between the use of LLDs and health outcomes, some beneficial, especially, with regard to certain types of cancer, but with a higher risk of cognitive decline. Further studies are warranted to clarify the health effects of these medications in the elderly.

Low levels of low-density lipoprotein cholesterol and cognitive decline

The relationship between low levels of serum low-density lipoprotein cholesterol (LDL-C) and subsequent cognitive decline remains unclear. The present study aimed to evaluate the longitudinal association between low LDL-C levels and cognition decline in the context of the current aggressive guideline-recommended targets (LDL-C levels less than 55 mg/dL for individuals at very high risk of cardiovascular events, and less than 70 mg/dL for high risk individuals). Data from wave 13 (2016) to wave 14 (2018) of the Health and Retirement Study (HRS) were utilized. LDL-C concentrations measured at wave 13 were categorized into 5 levels, reflecting currently recommended values for lipid lowering treatment. Of 7129 included participants (mean age: 69.0 ± 9.9 years, 60.3% female), we found that compared to participants with LDL-C levels of 70.0-99.9 mg/dL, those with LDL-C levels of <55 mg/dL had significantly slower 2-year decline rates in global cognitive function (0.244 point/year; 95% confidence interval (CI): 0.065-0.422; P = 0.008), working memory (0.068 point/year; 95% CI: 0.004-0.133; P = 0.038), and borderline significantly in episodic memory (0.155 point/year; 95% CI: -0.004-0.315; P = 0.057). Similarly, significantly slower decline rates were observed in those with LDL-C levels of 55.0-69.9 mg/dL. The present study demonstrated that compared with LDL-C levels 70.0-99.9 mg/dL, low LDL-C levels (<70 mg/dL, especially <55 mg/dL) were associated with significantly slower cognitive decline in population-based setting. Future randomized controlled trials are warranted to ascertain the safety and benefit of current aggressive guideline-recommended targets on cognitive function.

Baseline Cognitive Impairment in Patients With Asymptomatic Carotid Stenosis in the CREST-2 Trial

BACKGROUND AND PURPOSE

Studies of carotid artery disease have suggested that high-grade stenosis can affect cognition, even without stroke. The presence and degree of cognitive impairment in such patients have not been reported and compared with a demographically matched population-based cohort.

METHODS

We studied cognition in 1000 consecutive CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) patients, a treatment trial for asymptomatic carotid disease. Cognitive assessment was after randomization but before assigned treatment. The cognitive battery was developed in the general population REGARDS Study (Reasons for Geographic and Racial Differences in Stroke), involving Word List Learning Sum, Word List Recall, and Word List fluency for animal names and the letter F. The carotid stenosis patients were >45 years old with ≥70% asymptomatic carotid stenosis and no history of prevalent stroke. The distribution of cognitive performance for the patients was standardized, accounting for age, race, and education using performance from REGARDS, and after further adjustment for hypertension, diabetes, dyslipidemia, and smoking. Using the Wald Test, we tabulated the proportion of Z scores less than the anticipated deviate for the population-based cohort for representative percentiles.

RESULTS

There were 786 baseline assessments. Mean age was 70 years, 58% men, and 52% right-sided stenosis. The overall Z score for patients was significantly below expected for higher percentiles (P<0.0001 for 50th, 75th, and 95th percentiles) and marginally below expected for the 25th percentile (P=0.015). Lower performance was attributed largely to Word List Recall (P<0.0001 for all percentiles) and for Word List Learning (50th, 75th, and 95th percentiles below expected, P≤0.01). The scores for left versus right carotid disease were similar.

CONCLUSIONS

Baseline cognition of patients with severe carotid stenosis showed below normal cognition compared to the population-based cohort, controlling for demographic and cardiovascular risk factors. This cohort represents the largest group to date to demonstrate that poorer cognition, especially memory, in this disease.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02089217.

Statins and cognitive decline in the Cardiovascular Health Study: A comparison of different analytical approaches

BACKGROUND

Despite their well-established benefits for the prevention of cardiovascular disease, robust evidence on the effects of statins on cognition is largely inconclusive. We apply various study designs and analytical approaches to mimic randomized controlled trial (RCT) effects from observational data.

METHODS

We used observational data from 5,580 participants enrolled in the Cardiovascular Health Study from 1989/90 to 1999/2000. We conceptualized the cohort as an overlapping sequence of non-randomized trials. We compared multiple selection (eligible population, prevalent users, new-users) and analytic approaches (multivariable adjustment, inverse probability treatment weights, propensity score matching) to evaluate the association between statin use and 5-year change in global cognitive function, assessed using the Modified Mini-Mental State (3MS) examination.

RESULTS

When comparing prevalent users to non-users (N=2,772), statin use was associated with slower cognitive decline over 5 years (adjusted annual change in 3MSE = 0.34 points/year; 95% CI:0.05;0.63). Compared to prevalent user design, estimates from new user designs (e.g. comparing eligible statin initiators to non-initiators) were attenuated showing either null or negative association, though not significant. For example, in a propensity score-matched sample of statin-eligible individuals (N=454), annual 3MS change comparing statin initiators to non-initiators was -0.21 points/year (95% CI:-0.81;0.39).

CONCLUSIONS

The association of statin use and cognitive decline is attenuated towards the null when using rigorous analytical approaches that more closely mimic RCTs. Point estimates, even within the same study, may vary depending on the analytical methods used. Further studies that leverage natural or quasi experiments around statin use are needed to replicate our findings.

Alirocumab treatment and neurocognitive function according to the CANTAB scale in patients at increased cardiovascular risk: A prospective, randomized, placebo-controlled study

BACKGROUND AND AIMS

Trials of the fully human monoclonal antibody proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9) alirocumab in hypercholesterolemia demonstrated substantial low-density lipoprotein cholesterol (LDL-C) lowering, reduction in cardiovascular (CV) events and outcomes, and a generally acceptable safety and tolerability profile. The impact of maintaining low LDL-C levels on higher order brain function is unclear, with reports of neurocognitive disorders with other lipid-lowering therapies.

METHODS

Patients (n = 2176) with heterozygous familial hypercholesterolemia (HeFH) or non-FH, at high or very-high CV risk despite maximally tolerated statin therapy, randomly received subcutaneous alirocumab 75/150 mg or placebo every 2 weeks in this double-blind, placebo-controlled trial. The primary outcome was prospectively evaluated every 24 weeks over 96 weeks by Cambridge Neuropsychological Test Automated Battery (CANTAB).

RESULTS

Among 2086 patients with CANTAB cognitive domain Spatial Working Memory Strategy (SWMS) assessments, change from baseline to Week 96 in SWMS z-score (primary outcome) achieved noninferiority between alirocumab and placebo (least squares [LS] mean change at Week 96, -0.180 vs -0.200; LS mean difference vs placebo [95% confidence interval]: -0.020 [-0.094 to 0.055], p = 0.6055). Exploratory outcome measures, which further assessed neurocognitive function in the CANTAB domains, did not differ significantly over 96 weeks and achieved nominal noninferiority between treatment groups. Alirocumab resulted in nominally significant reductions in LDL-C and other lipid parameters, and was generally well tolerated.

CONCLUSIONS

Confirming previous PCSK9 inhibitor data, alirocumab showed no effect on neurocognitive function over 96 weeks' treatment, substantially reduced LDL-C and was generally well tolerated in patients with HeFH or non-FH at high or very-high CV risk.

Association of statin use in older people primary prevention group with risk of cardiovascular events and mortality: a systematic review and meta-analysis of observational studies

BACKGROUND

Current evidence from randomized controlled trials on statins for primary prevention of cardiovascular disease (CVD) in older people, especially those aged > 75 years, is still lacking. We conducted a systematic review and meta-analysis of observational studies to extend the current evidence about the association of statin use in older people primary prevention group with risk of CVD and mortality.

METHODS

PubMed, Scopus, and Embase were searched from inception until March 18, 2021. We included observational studies (cohort or nested case-control) that compared statin use vs non-use for primary prevention of CVD in older people aged ≥ 65 years; provided that each of them reported the risk estimate on at least one of the following primary outcomes: all cause-mortality, CVD death, myocardial infarction (MI), and stroke. Risk estimates of each relevant outcome were pooled as a hazard ratio (HR) with a 95% confidence interval (CI) using the random-effects meta-analysis model. The quality of the evidence was rated using the GRADE approach.

RESULTS

Ten observational studies (9 cohorts and one case-control study; n = 815,667) fulfilled our criteria. The overall combined estimate suggested that statin therapy was associated with a significantly lower risk of all-cause mortality (HR: 0.86 [95% CI 0.79 to 0.93]), CVD death (HR: 0.80 [95% CI 0.78 to 0.81]), and stroke (HR: 0.85 [95% CI 0.76 to 0.94]) and a non-significant association with risk of MI (HR 0.74 [95% CI 0.53 to 1.02]). The beneficial association of statins with the risk of all-cause mortality remained significant even at higher ages (> 75 years old; HR 0.88 [95% CI 0.81 to 0.96]) and in both men (HR: 0.75 [95% CI: 0.74 to 0.76]) and women (HR 0.85 [95% CI 0.72 to 0.99]). However, this association with the risk of all-cause mortality remained significant only in those with diabetes mellitus (DM) (HR 0.82 [95% CI 0.68 to 0.98]) but not in those without DM. The level of evidence of all the primary outcomes was rated as "very low."

CONCLUSIONS

Statin therapy in older people (aged ≥ 65 years) without CVD was associated with a 14%, 20%, and 15% lower risk of all-cause mortality, CVD death, and stroke, respectively. The beneficial association with the risk of all-cause mortality remained significant even at higher ages (> 75 years old), in both men and women, and in individuals with DM, but not in those without DM. These observational findings support the need for trials to test the benefits of statins in those above 75 years of age.

Cognition, Statins, and Cholesterol in Elderly Ischemic Stroke Patients: A Neurologist's Perspective

Background and Objectives: The efficacy of hydroxy methyl glutaryl-coenzyme A reductase inhibitors (statins) in reducing the incidence of cardiovascular events pushed the target LDL-cholesterol (LDL-C) levels lower and lower in successive guidelines despite signals regarding potential cognitive side effects. We evaluated the relationship between cognitive impairment and LDL-C levels in elderly ischemic stroke patients. Materials and Methods: 29 ischemic stroke patients aged 65 and above with LDL-C levels ≤70 mg/dL, classified according to the TOAST criteria, underwent detailed neuropsychological testing comprising the MMSE test, Montreal Cognitive Assessment (MoCA) and Addenbrooke’s Cognitive Evaluation (ACE-III) test. Their performances were compared to those of 29 age-matched ischemic stroke patients with LDL-Cl levels >71 mg/dL. Results: The MMSE test failed to detect significant cognitive differences between the two groups. The MoCA and ACE-III tests detected impairments in visuo-spatial/executive function, attention, and recall/memory in patients with low LDL-C. A stepwise linear regression model of the ACE-III total scores revealed that LDL-cholesterol levels could contribute to 13.8% of the detected cognitive dysfunction, second in importance only to age, which contributed to 38.8% of the detected impairment. Conclusions: Physicians should be cautious when prescribing statins to elderly people. Hydrophilic ones may be preferred in cognitively impaired patients.

High burden of cerebral white matter lesion in 9 Asian cities

Age-related white matter lesion (WML) is considered a manifestation of sporadic cerebral small vessel disease and an important pathological substrate for dementia. Asia is notable for its large population with a looming dementia epidemic. Yet, the burden of WML and its associated risk factors across different Asian societies are unknown. Subjects from 9 Asian cities (Bangkok, Bandung, Beijing, Bengaluru, Hong Kong, Kaohsiung, Manila, Seoul, and Singapore) were recruited (n = 5701) and classified into (i) stroke/transient ischemic attack (TIA), (ii) Alzheimer's disease (AD)/mild cognitive impairment (MCI), or (iii) control groups. Data on vascular risk factors and cognitive performance were collected. The severity of WML was visually rated on MRI or CT. The prevalence of moderate-to-severe WML was the highest in subjects with stroke/TIA (43.3%). Bandung Indonesia showed the highest prevalence of WML, adjusted for age, sex, education, disease groups, and imaging modality. Hypertension and hyperlipidemia were significant risk factors for WML, and WML was negatively associated with MMSE in all groups. WML is highly prevalent in Asia and is associated with increasing age, hypertension, hyperlipidemia, and worse cognitive performance. Concerted efforts to prevent WML will alleviate the huge dementia burden in the rapidly aging Asian societies.

Effect of Statin Therapy on Cognitive Decline and Incident Dementia in Older Adults

BACKGROUND

The neurocognitive effect of statins in older adults remain uncertain.

OBJECTIVES

The aim of this study was to investigate the associations of statin use with cognitive decline and incident dementia among older adults.

METHODS

This analysis included 18,846 participants ≥65 years of age in a randomized trial of aspirin, who had no prior cardiovascular events, major physical disability, or dementia initially and were followed for 4.7 years. Outcome measures included incident dementia and its subclassifications (probable Alzheimer's disease, mixed presentations); mild cognitive impairment (MCI) and its subclassifications (MCI consistent with Alzheimer's disease, other MCI); and changes in domain-specific cognition, including global cognition, memory, language and executive function, psychomotor speed, and the composite of these domains. Associations of baseline statin use versus nonuse with dementia and MCI outcomes were examined using Cox proportional hazards models and with cognitive change using linear mixed-effects models, adjusting for potential confounders. The impact of statin lipophilicity on these associations was further examined, and effect modifiers were identified.

RESULTS

Statin use versus nonuse was not associated with dementia, MCI, or their subclassifications or with changes in cognitive function scores over time (p > 0.05 for all). No differences were found in any outcomes between hydrophilic and lipophilic statin users. Baseline neurocognitive ability was an effect modifier for the associations of statins with dementia (p for interaction < 0.001) and memory change (p for interaction = 0.02).

CONCLUSIONS

In adults ≥65 years of age, statin therapy was not associated with incident dementia, MCI, or declines in individual cognition domains. These findings await confirmation from ongoing randomized trials.

Effects of statins on mitochondrial pathways

Statins are a family of drugs that are used for treating hyperlipidaemia with a recognized capacity to prevent cardiovascular disease events. They inhibit β-hydroxy β-methylglutaryl-coenzyme A reductase, i.e. the rate-limiting enzyme in mevalonate pathway, reduce endogenous cholesterol synthesis, and increase low-density lipoprotein clearance by promoting low-density lipoprotein receptor expression mainly in the hepatocytes. Statins have pleiotropic effects including stabilization of atherosclerotic plaques, immunomodulation, anti-inflammatory properties, improvement of endothelial function, antioxidant, and anti-thrombotic action. Despite all beneficial effects, statins may elicit adverse reactions such as myopathy. Studies have shown that mitochondria play an important role in statin-induced myopathies. In this review, we aim to report the mechanisms of action of statins on mitochondrial function. Results have shown that statins have several effects on mitochondria including reduction of coenzyme Q10 level, inhibition of respiratory chain complexes, induction of mitochondrial apoptosis, dysregulation of Ca2+ metabolism, and carnitine palmitoyltransferase-2 expression. The use of statins has been associated with the onset of additional pathological conditions like diabetes and dementia as a result of interference with mitochondrial pathways by various mechanisms, such as reduction in mitochondrial oxidative phosphorylation, increase in oxidative stress, decrease in uncoupling protein 3 concentration, and interference in amyloid-β metabolism. Overall, data reported in this review suggest that statins may have major effects on mitochondrial function, and some of their adverse effects might be mediated through mitochondrial pathways.

Association between Previous Statin Use and Alzheimer's Disease: A Nested Case-Control Study Using a National Health Screening Cohort

A number of studies report the incidence of Alzheimer’s disease (AD) in patients taking statins, but the results are inconsistent. (1) Background: The present study investigated the cross-sectional association between previous statin use and the risk of AD development in Korean residents. (2) Methods: We used the Korean National Health Insurance Service-National Sample Cohort; 17,172 AD patients were matched by age, gender, income, and region of residence with 68,688 control participants at a ratio of 1:4. We used a multiple conditional logistic regression model to analyse the association between the number of days of statin use and AD occurrence. Further analyses were performed to identify whether this association is maintained for different ages, genders, socioeconomic status groups, and covariates. (3) Results: The odds ratio, which was adjusted for potential confounders, for the days of statin use per year in the AD group compared to the control group was 0.95 (95% confidence interval = 0.92–0.98; p = 0.003). The number of days of statin use in the AD group was significantly smaller in the subgroups of non-smokers and individuals with normal weight, alcohol consumption less than once a week, total cholesterol level below 200 mg/dL, systolic blood pressure below 140, diastolic blood pressure below 90, and fasting blood glucose below 100 mg/dL. (4) Conclusions: Our results suggest that statin use prevents the occurrence of AD. The effects of statin use in preventing AD may be greater in individuals at relatively low risk.