Statin use and cognitive function: population-based observational study with long-term follow-up

Cholesterol Management in Neurology: Time for Revised Strategies?

Statin therapy has been extensively evaluated and shown to reduce the incidence of new or recurrent vascular events, ischemic stroke included. As a consequence, each published guideline pushes for lower low-density cholesterol levels in the population at large, recommending increased statin doses and/or adding new cholesterol-lowering molecules. Neurologists find it sometimes difficult to apply these guidelines, having to confront situations such as (1) ischemic strokes, mainly cardioembolic ones, in patients with already low LDL-cholesterol levels; (2) myasthenic patients, whose lifespan has been extended by available treatment, and whose age and cholesterol levels put them at risk for ischemic stroke; (3) patients with myotonic dystrophy, whose disease often associates diabetes mellitus and heart conduction defects, and in whom blood cholesterol management is also not settled. As such, further trials are needed to address these issues.

Association of Endogenous Erythropoietin Levels and Iron Status With Cognitive Functioning in the General Population

Background

Emerging data suggest that erythropoietin (EPO) promotes neural plasticity and that iron homeostasis is needed to maintain normal physiological brain function. Cognitive functioning could therefore be influenced by endogenous EPO levels and disturbances in iron status.

Objective

To determine whether endogenous EPO levels and disturbances in iron status are associated with alterations in cognitive functioning in the general population.

Materials and Methods

Community-dwelling individuals from the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study, a general population-based cohort in Groningen, Netherlands, were surveyed between 2003 and 2006. Additionally, endogenous EPO levels and iron status, consisting of serum iron, transferrin, ferritin, and transferrin saturation were analyzed. Cognitive function was assessed by scores on the Ruff Figural Fluency Test (RFFT), as a reflection of executive function, and the Visual Association Test (VAT), as a reflection of associative memory.

Results

Among 851 participants (57% males; mean age 60 ± 13 years), higher endogenous EPO levels were independently associated with an improved cognitive function, reflected by RFFT scores (ß = 0.09, P = 0.008). In multivariable backward linear regression analysis, EPO levels were among the most important modifiable determinants of RFFT scores (ß = 0.09, P = 0.002), but not of VAT scores. Of the iron status parameters, only serum ferritin levels were inversely associated with cognitive function, reflected by VAT scores, in multivariable logistic regression analysis (odds ratio, 0.77; 95% confidence interval 0.63–0.95; P = 0.02 for high performance on VAT, i.e., ≥11 points). No association between iron status parameters and RFFT scores was identified.

Conclusion

The findings suggest that endogenous EPO levels and serum ferritin levels are associated with specific cognitive functioning tests in the general population. Higher EPO levels are associated with better RFFT scores, implying better executive function. Serum ferritin levels, but not other iron status parameters, were inversely associated with high performance on the VAT score, implying a reduced ability to create new memories and recall recent past. Further research is warranted to unravel underlying mechanisms and possible benefits of therapeutic interventions.

Personalized treatment selection using observational data

Estimating the optimal treatment regime based on individual patient characteristics has been a topic of discussion in many forums. Advanced computational power has added momentum to this discussion over the last two decades and practitioners have been advocating the use of new methods in determining the best treatment. Treatments that are geared toward the 'best' outcome for a patient based on his/her genetic markers and characteristics are of high importance. In this article, we develop an approach to predict the optimal personalized treatment based on observational data. We have used inverse probability of treatment weighted machine learning methods to obtain score functions to predict the optimal treatment. Extensive simulation studies showed that our proposed method has desirable performance in selecting the optimal treatment. We provided a case study to examine the Statin use on cognitive function to illustrate the use of our proposed method.

The efficacy of statins in the treatment of Alzheimer's disease: a meta-analysis of randomized controlled trial

OBJECTIVE

Alzheimer's disease (AD) is a common type of dementia, which has caused heavy global economic and health burden, and the using of statins to treat AD has caused widely debated. The purpose of this meta-analysis is to explore the effect of statins in the treatment of Alzheimer's disease.

METHODS

Studies were retrieved by searching PubMed, Embase, Cochrane library, OvisdSP, Web of Science, Chinese Nation Knowledge Infrastructure (CNKI) and Chinese Biomedical Database (CBM) databases before March 31, 2019. We extracted the Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-cognitive (ADAS-Cog), Neuropsychiatric Inventory (NPI), Activities of Daily Living (ADL) scale score, and other information. The pooled Weighted Mean Difference (WMD) and their 95% confidence intervals (95% CI) were calculated with random effect model or fixed random effect model.

RESULTS

A total of nine randomized controlled trials were included that contained 1489 patients; of them, 742 patients in the statins group, 747 patients in the control group. There were nine studies used the MMSE scale, five studies used the ADAS-Cog scale, four studies used the NPI scale, and six studies used the ADL scale. Meta-analysis of the nine studies that reported the MMSE scale scores indicated that there is no significant effect of statins as compared with control group (the pooled WMD = 1.09, 95% CI, - 0.00, 2.18, p = 0.05, I2 = 87.9%). Meta-analysis of the five studies that reported the ADAS-Cog scale scores also indicated that there is no significant effect of statins as compared with control group (the pooled WMD = - 0.16, 95% CI, - 2.67, 2.36, p = 0.90, I2 = 80.1%). Meta-analysis of the four studies that reported the NPI scale scores indicated that treatment with statins could slow the rise in the NPI scale scores (the pooled WMD = - 1.16, 95% CI, - 1.88, - 0.44, p = 0.002, I2 = 45.4%). Meta-analysis of the six studies that reported the ADL scale scores indicated that treatment with statins could improve patients' daily living ability (the pooled WMD = - 4.06, 95% CI, - 6.88, - 1.24, p = 0.005, I2 = 86.7%). Results of subgroup analysis indicated that the use of statins in the short term (≤ 12 months) associated with the change of the MMSE scale scores (the pooled WMD = 1.78, 95% CI, 0.53, 3.04, p = 0.005, I2 = 79.6%). Sensitivity analysis and publication bias test were both negative, and the results were relatively reliable and stable.

CONCLUSION

Statins used in AD patients had beneficial effects on the scores of MMSE scale in the short term (≤ 12 months), and statins could slow the deterioration of neuropsychiatric status and significantly improve activities of daily living ability in AD patients, but statins did not show an advantage in the change of the ADAS-Cog scale scores.

Effects of commonly prescribed drugs on cognition and mild cognitive impairment in healthy elderly people

BACKGROUND

Chronic drug intake has been associated with negative and positive cognitive effects in elderly people, although subjacent conditions may be confounding factors.

AIM

To study the effects on cognitive performance of commonly prescribed medications in a cohort of cognitively normal older adults.

METHODS

Medication intake was recorded during two years in 1087 individuals 70-85 years old, without neurological or psychiatric conditions. The influence of every drug, drug family and therapeutic group on six cognitive scores and on the conversion to mild cognitive impairment over two years was ascertained by cross-sectional and longitudinal analyses controlling for demographic and clinical variables.

RESULTS

Small effects of several drugs on information processing were found in cross-sectional analyses but only confirmed for a positive effect of vitamin D in case-control analyses. Longitudinal analyses showed no drug effects on the cognitive slopes. Several hypotensive drugs reduced, whereas bromazepam and glucose lowering drugs increased, the conversion rate to mild cognitive impairment with very small effects (R²=0.3-1%).

CONCLUSIONS

Cognitively healthy elderly individuals show minimal negative effects on information processing associated with chronic intake of some drugs probably related to the subjacent condition. Some drugs slightly affect the rate of conversion to mild cognitive impairment. Positive effects of vitamin D, chondroitin, atorvastatin and antihypertensive drugs, and negative effects of antidepressants and benzodiazepines, should be further explored in studies with longer follow-up.

Pharmacoepidemiology of statins

The evaluation of the real-life benefits and risks of statins in population is a major pharmacoepidemiological issue, given their widespread use for cardiovascular prevention. The purpose of this review was not to be exhaustive but to show the contributions of pharmacoepidemiology for various aspects of the evaluation of statins such as real-life drug use, effectiveness and risk. Statins are among the most used drugs in the world, but recent data show a slight decrease in use. Actual statin users are older, and have more comorbidities than those studied in clinical trials, but this does not seem to compromise their effectiveness, unlike the compliance issues that are common with these drugs. Beyond the known adverse reactions of statins from the clinical trials, risks of statins can be varied and sometimes difficult to evaluate, considering the ubiquity of cholesterol throughout the body, from drug or endogenous molecule metabolism to the construction of cell membranes or cell activities.

Management of Atherosclerotic Cardiovascular Disease Risk Factors in the Older Adult Patient With Diabetes

: Older adults with diabetes are at higher risk for atherosclerotic cardiovascular disease (ASCVD) than younger adults with diabetes and older adults without diabetes. The rationale to implement ASCVD risk-lowering therapies in older adults with diabetes is compelling. Recommendations for lifestyle modification, lipid-lowering therapy, blood pressure management, blood glucose control, and aspirin therapy are often based on studies that show their efficacy in younger populations. However, the risks associated with each of these interventions increase with age, and favorable risk-to-benefit ratios demonstrated in younger adults with diabetes are less certain in older populations. The variability in health status among older adults is pertinent. Those with robust health are more likely to tolerate and derive benefit from many therapies when compared with those who have more complex health including frailty. Age- and/or frailty-stratified data to help clarify these relationships are sparse. In this Perspective, current recommendations for modifying ASCVD risk are described with a review of the pertinent literature that guides their application in older adults. A pragmatic approach to the treatment of ASCVD risk factors in older adults with diabetes is presented.

Hypolipidemic drugs in elderly subjects: Indications and limits

AIMS

Cardiovascular disease is a major cause of death worldwide. Safety and efficacy of lipid lowering therapy have been clearly established for either primary and secondary prevention of cardiovascular events in adults. Nevertheless, the use of hypolipidemic drugs in elderly individuals, especially in the oldest ones, still raises some concerns. Aim of this paper is to review indications and limits of lipid lowering in advanced age, furnishing a practical medical attitude tempered by clinical and geriatric competences.

DATA SYNTHESIS

While figures from randomized controlled trials and from observational studies seem to support the use of lipid lowering drugs for secondary prevention in the elderly, drawing inferences from primary prevention in old populations is far more challenging. Although these pharmacological agents seem to reduce the incidence of cardiovascular events, they do not prolong survival. In addition, there is some doubt about the cost-effectiveness of treatment because of a more delicate balance between benefit and potential adverse reactions. However, lipid-lowering drugs seem largely underutilized in older age, mainly due to safety concerns that must be reconsidered, at least in part, given the somewhat reassuring results deriving from specific cohort surveys.

CONCLUSIONS

Data on the use and on the effects of lipid lowering drugs in elderly populations are incomplete, especially those concerning very old subjects without established cardiovascular disease. Comprehensive guidelines for the management of dyslipidemias in this rapidly-growing population is a urgent need, and treatment should be based, besides the aforementioned considerations, on patient preferences, cognitive function and life expectancy.

Additional therapy for cholesterol lowering in ezetimibe-treated, statin-intolerant patients in clinical practice: results from an internal audit of a university lipid clinic

OBJECTIVE

The aim of our study was to evaluate the tolerability and efficacy of alternative approaches to improve cholesterolemia control in patients with statin-related myalgia treated with ezetimibe.

RESEARCH DESIGN AND METHODS

We retrospectively evaluated 3534 Clinical Report Forms (CRFs) filled in the period June 2012-June 2015 for first visits to the lipid clinic of the University of Bologna. For this study, we selected 252 CRFs based on the following criteria: statin-related myalgia, previous failed treatment with at least two low-dosed statins, well tolerated treatment with ezetimibe. Then, the following lipid-lowering treatments were added in order to improve the ezetimibe low density lipoprotein cholesterol (LDL-C) lowering efficacy, based on clinical judgment: fenofibrate 145 mg, rosuvastatin 5 mg 1 tablet/week, rosuvastatin 5 mg 2 tablets/week, red yeast rice (standardized in monacolin K 3 mg) + berberine 500 mg, berberine 500 mg b.i.d., phytosterols 900 mg + psyllium fiber 3.5 g b.i.d. Patients continuing to claim a tolerable myalgia were then treated with coenzyme Q10 nanoemulsions 200 mg/day.

RESULTS

The treatment with standard lipid-lowering diet plus ezetimibe alone was associated with a mean LDL-C reduction of 17 ± 2%. The additive LDL-lowering effect with the various tested treatment was: -16 ± 2% with fenofibrate 145 mg/day, -13 ± 1% with rosuvastatin 5 mg 1 tablet/week, -17 ± 3% with rosuvastatin 5 mg 2 tablets/week, -19 ± 4% with red yeast rice + berberine, -17 ± 4% with berberine b.i.d. and -10 ± 3% with phytosterols + psyllium b.i.d.; 11% of the patients treated with fenofibrate required treatment modification because of myalgia recurrence, while the percentage was negligible for the other tested treatments. In patients with residual tolerable myalgia, treatment with coenzyme Q10 for 8 weeks was associated with a mean improvement of the graduated myalgia score from 4.8 ± 1.9 to 2.9 ± 1.3 (p = 0.013).

CONCLUSIONS

Some alternative treatments seems to be effective and well tolerated, thus improving the ezetimibe effect on cholesterolemia.

Serum low-density lipoprotein levels, statin use, and cognition in patients with coronary artery disease

AIM

Statins have been associated with decreased cognition due to the effects of low concentrations of low-density lipoprotein (LDL) on brain function. This has remained controversial and is particularly relevant to patients with coronary artery disease (CAD), who have an increased risk of cognitive decline and are frequently prescribed statins. This study hypothesized that low concentration of LDL is associated with poor cognition in CAD patients using statins. It also explored the association between high-dose versus low-dose statins on cognition in this population.

PATIENTS AND METHODS

Baseline cross-sectional data from a longitudinal study of 120 statin-using CAD patients were examined (mean statin duration 25±43 months). The main outcomes were measures of global cognition and cognitive domains, with poor cognition defined as cognitive performance ≤1 standard deviation below the population age and education adjusted means. A battery of cognitive tests was used to assess verbal memory, executive function, speed of processing, visuospatial memory, and global cognition. Adjusting for age, sex, education, and other covariates, multivariable logistic regression analyses assessed associations between low LDL levels (<1.5 mmol/L), statin use, and poor cognition.

RESULTS

LDL levels were not associated with global cognition or individual cognitive domains. High-dose statin use was associated with higher visuospatial memory (odds ratio, OR [95% confidence interval, CI] =0.12 [0.02-0.66], P=0.01) and executive functioning (OR =0.25 [0.06-0.99], P=0.05). This effect was independent of covariates such as LDL levels.

CONCLUSION

Low LDL levels do not appear to be associated with poor cognition in CAD patients using statins. Whether high-dose statin use may have positive effects on cognition in CAD patients could be investigated in future studies.

Statin use and cognitive function: population-based observational study with long-term follow-up

We aimed to evaluate the association between statin use and cognitive function. Cognitive function was measured with the Ruff Figural Fluency Test (RFFT; worst score, 0; best score, 175 points) and the Visual Association Test (VAT; low performance, 0-10; high performance, 11-12 points) in an observational study that included 4,095 community-dwelling participants aged 35-82 years. Data on statin use were obtained from a computerized pharmacy database. Analysis were done for the total cohort and subsamples matched on cardiovascular risk (N = 1232) or propensity score for statin use (N = 3609). We found that a total of 904 participants (10%) used a statin. Statin users were older than non-users: mean age (SD) 61 (10) vs. 52 (11) years (p < 0.001). The median duration of statin use was 3.8 (interquartile range, 1.6-4.5) years. Unadjusted, statin users had worse cognitive performance than non-users. The mean RFFT score (SD) in statin users and non-users was 58 (23) and 72 (26) points, respectively (p < 0.001). VAT performance was high in 261 (29%) statin users and 1351 (43%) non-users (p < 0.001). However, multiple regression analysis did not show a significant association of RFFT score with statin use (B, -0.82; 95%CI, -2.77 to 1.14; p = 0.41) nor with statin solubility, statin dose or duration of statin use. Statin users with high doses or long-term use had similar cognitive performance as non-users. This was found in persons with low as well as high cardiovascular risk, and in younger as well as older subjects. Also, the mean RFFT score per quintile of propensity score for statin use was comparable for statin users and non-users. Similar results were found for the VAT score as outcome measure. In conclusion, statin use was not associated with cognitive function. This was independent of statin dose or duration of statin use.