Review of the Protective Effects of Statins on Cognition

Drug-Induced Cognitive Impairment

Drug-induced cognitive impairment (DICI) is a well-established, yet under-recognised, complication of many types of pharmacological treatment. While there is a large body of scientific literature on DICI, most papers are about drug-induced dementia in the elderly and one specific drug class. However, DICI also comprises subclinical symptoms, domain-specific forms of cognitive impairment as well as mild cognitive impairment (MCI), and delirium. Even mild forms of DICI, if not recognised as such, can have deleterious and life-long consequences. In addition, DICI also occurs in younger adults and in children, and has been reported with many different drug classes. The aim of this review is to raise awareness of DICI by providing an overview on the type(s) and symptoms of observed DICI and the suspected underlying mechanism(s) for various drug classes: antiseizure medications, antidepressants, antiparkinsonian drugs, antipsychotics, lithium, benzodiazepines/Z-drugs, opioids, first-generation antihistamines, drugs for urinary incontinence, proton pump inhibitors, glucocorticoids, NSAIDs, statins, antihypertensives, and chemotherapeutic agents.

Do Statins Affect Cognitive Health? A Narrative Review and Critical Analysis of the Evidence

PURPOSE OF REVIEW

Statins are the first-line treatment for hypercholesterolemia and play a key role in the prevention of cardiovascular disease (CVD). Current studies report mixed effects of statins on cognitive health, including harmful, neutral, and protective outcomes. However, these ongoing controversies about the potential cognitive adverse effects of statins may compromise their use in CVD prevention. Several factors may influence how statins affect cognition, including the unique cholesterol homeostasis in the brain, the limited permeability of the blood-brain barrier to lipoproteins, and the varying lipophilicity of different statins. This review examines the evidence linking statins to cognitive function and considers the effect of different dosages and treatment durations.

RECENT FINDINGS

Earlier studies suggested cognitive disturbances with statins, but recent evidence does not strongly support a link between statins and cognitive impairment. In fact, observational studies suggest potential neuroprotective benefits, though biases like selection bias, confounding and reverse causation limit definitive conclusions. Two large randomized controlled trials, STAREE and PREVENTABLE, are underway, and their results are expected to address some of these gaps in the literature. Due to insufficient evidence in the current literature, well-designed randomized controlled trials are needed for a better understanding of statins' effects on cognition. More data is needed regarding statin type, dose intensity, and treatment duration, which may affect cognitive outcomes. Future studies are also needed to examine how statins may affect cognition in specific high-risk groups, such as individuals with mild cognitive impairment, diabetes, cardiovascular disease, or chronic kidney disease.

Serum metabolomics analysis combined with network pharmacology reveals possible mechanisms of postoperative cognitive dysfunction in the treatment of Mongolian medicine Eerdun Wurile basic formula

This study analyzed the endogenous metabolites and metabolic pathways in the serum of Sprague-Dawley (SD) rats gavaged with the Eerdun Wurile basic formula (EWB) using metabolomics methods and network pharmacology to explore the possible mechanism of action of the EWB in improving postoperative cognitive dysfunction (POCD). SD rats were divided into the basic formula group, which received the EWB, and the control group, which received equal amounts of distilled water. The blood was collected from the abdominal aorta and analyzed for metabolite profiles using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). Network pharmacology predicts the targets of the differential metabolites and disease targets; takes the intersection and constructs a "metabolite-disease-target" network; and performs protein-protein interaction, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes analyses. A total of 56 metabolites were selected for significant differences between the groups, mainly affecting amphetamine addiction, alcoholism, and regulation of lipolysis in adipocytes. A total of 177 potential targets for differential metabolite action in POCD were selected. The PI3K-Akt pathway, the HIF-1 pathway, and the FoxO pathway were in key positions. The studies have shown that EWB could improve POCD through multicomponents, multitargets, and multipathways, providing new possibilities and reference values for the treatment of POCD.

Statins and cognition: Modifying factors and possible underlying mechanisms

Statins are a class of widely prescribed drugs used to reduce low-density lipoprotein cholesterol (LDL-C) and important to prevent cardiovascular diseases (CVD). Most statin users are older adults with CVD, who are also at high risk of cognitive decline. It has been suggested that statins can alter cognitive performance, although their positive or negative effects are still debated. With more than 200 million people on statin therapy worldwide, it is crucial to understand the reasons behind discrepancies in the results of these studies. Here, we review the effects of statins on cognitive function and their association with different etiologies of dementia, and particularly, Alzheimer's disease (AD). First, we summarized the main individual and statin-related factors that could modify the cognitive effects of statins. Second, we proposed the underlying mechanisms for the protective and adverse effects of statins on cognitive performance. Finally, we discussed potential causes of discrepancies between studies and suggested approaches to improve future studies assessing the impact of statins on dementia risk and cognitive function.