Valproate attenuates the risk of myocardial infarction in patients with epilepsy: a nationwide cohort study

Genetic variation supports a causal role for valproate in prevention of ischemic stroke

BACKGROUND

Valproate is a candidate for ischemic stroke prevention due to its anti-atherosclerotic effects in vivo. Although valproate use is associated with decreased ischemic stroke risk in observational studies, confounding by indication precludes causal conclusions.

AIMS

We applied Mendelian randomization to determine whether genetic variants that influence seizure response among valproate users associate with ischemic stroke.

METHODS

We derived a genetic score for valproate response using genome-wide association data of seizure response after valproate intake from the Epilepsy Pharmacogenomics Consortium. We then tested this score among valproate users of the UK Biobank for association with incident and recurrent ischemic stroke using Cox proportional hazard models. As replication, we tested found associations in an independent cohort of valproate users of the Mass General Brigham Biobank.

RESULTS

Among 2150 valproate users (mean 56 years, 54% females), 82 ischemic strokes occurred over a mean 12 year follow-up. Higher valproate response genetic score was associated with higher serum valproate levels (+5.78 µg/ml per 1 standard deviation (SD), 95% confidence interval (CI) (3.45, 8.11)). After adjusting for age and sex, higher valproate response genetic score was associated with lower ischemic stroke risk (hazard ratio (HR) per 1 SD 0.73, 95% CI (0.58, 0.91)) with a halving of absolute risk in the highest compared to the lowest score tertile (4.8% vs 2.5%, p trend = 0.027). Among 194 valproate users with prevalent stroke at baseline, a higher valproate response genetic score was associated with lower recurrent ischemic stroke risk (HR per 1 SD 0.53, 95% CI (0.32, 0.86)) with reduced absolute risk in the highest compared to the lowest score tertile (3/51, 5.9% vs 13/71, 18.3%, p trend = 0.026). The valproate response genetic score was not associated with ischemic stroke among the 427,997 valproate non-users (p = 0.61), suggesting minimal pleiotropy. In 1241 valproate users of the Mass General Brigham Biobank with 99 ischemic stroke events over 6.5 years follow-up, we replicated our observed associations between the valproate response genetic score and ischemic stroke (HR per 1 SD 0.77, 95% CI (0.61, 0.97)).

CONCLUSION

These results demonstrate that a genetically predicted favorable seizure response to valproate is associated with higher serum valproate levels and reduced ischemic stroke risk among valproate users, providing causal support for valproate effectiveness in ischemic stroke prevention. The strongest effect was found for recurrent ischemic stroke, suggesting potential dual-use benefits of valproate for post-stroke epilepsy. Clinical trials will be required in order to identify populations that may benefit most from valproate for stroke prevention.

DATA ACCESS STATEMENT

UK Biobank participant data are available after approval of a research proposal. The weights of the used genetic scores are available in the Supplemental Tables.

HDAC9 Inhibition as a Novel Treatment for Stroke

The identification of a variant in the HDAC9 gene as a risk factor for large-artery atherosclerotic stroke, and subsequently coronary artery disease, has opened novel treatment pathways for stroke and more widely atherosclerotic disease. This article describes the pathway from gene discovery to novel therapeutic approaches that are now entering man. HDAC9 expression is elevated in human atherosclerotic plaque, while in animal and cellular models, reducing HDAC9 (histone deacetylase 9) protein is associated with reduced disease. Several mechanisms have been proposed to account for the association between HDAC9 and atherosclerosis including alterations in the inflammatory response and cholesterol efflux and endothelial-mesenchymal transition. The association raises the possibility that inhibiting HDAC9 may provide a novel treatment approach for atherosclerotic cardiovascular disease. This is supported by intervention studies demonstrating HDAC9 inhibition reduces atherosclerosis in animal and cellular models. Indirect data support such an approach in man. The antiseizure drug sodium valproate, which has nonspecific HDAC inhibitory properties, both inhibits atherosclerosis in animal models and is epidemiologically associated with reduced stroke and myocardial infarction risk in man. It is now being trailed in phase 2 studies in large-artery stroke, while more specific HDAC9 inhibitors are being developed.

Genetic variation supports a causal role for valproate in prevention of ischemic stroke

Valproate is a candidate for ischemic stroke prevention due to its anti-atherosclerotic effects in vivo. Although valproate use is associated with decreased ischemic stroke risk in observational studies, confounding by indication precludes causal conclusions. To overcome this limitation, we applied Mendelian randomization to determine whether genetic variants that influence seizure response among valproate users associate with ischemic stroke. We derived a genetic score for valproate response using genome-wide association data of seizure response after valproate intake from the Epilepsy Pharmacogenomics Consortium. We then tested this score among valproate users of the UK Biobank for association with incident and recurrent ischemic stroke using Cox proportional hazard models. Among 2,150 valproate users (mean 56 years, 54% females), 82 ischemic strokes occurred over a mean 12-year follow-up. Higher valproate response genetic score was associated with higher serum valproate levels (+5.78 μg/ml per one SD, 95% CI [3.45, 8.11]). After adjusting for age and sex, higher valproate response genetic score was associated with lower ischemic stroke risk (HR per one SD 0.73, [0.58, 0.91]) with a halving of absolute risk in the highest compared to the lowest score tertile (4.8% vs 2.5%, p-trend=0.027). Among 194 valproate users with prevalent stroke at baseline, a higher valproate response genetic score was associated with lower recurrent ischemic stroke risk (HR per one SD 0.53, [0.32, 0.86]) with reduced absolute risk in the highest compared to the lowest score tertile (3/51, 5.9% vs. 13/71, 18.3%, p-trend=0.026). The valproate response genetic score was not associated with ischemic stroke among the 427,997 valproate non-users (p=0.61), suggesting minimal pleiotropy. In an independent cohort of 1,241 valproate users of the Mass General Brigham Biobank with 99 ischemic stroke events over 6.5 years follow-up, we replicated our observed associations between the valproate response genetic score and ischemic stroke (HR per one SD 0.77, 95% CI: [0.61, 0.97]). These results demonstrate that a genetically predicted favorable seizure response to valproate is associated with higher serum valproate levels and reduced ischemic stroke risk among valproate users, providing causal support for valproate effectiveness in ischemic stroke prevention. The strongest effect was found for recurrent ischemic stroke, suggesting potential dual-use benefits of valproate for post-stroke epilepsy. Clinical trials will be required in order to identify populations that may benefit most from valproate for stroke prevention.

Identification of factors associated with new-onset vascular disease in patients admitted for video-EEG monitoring: A longitudinal cohort study

OBJECTIVE

People with epilepsy are at a higher risk of developing vascular disease. Understanding the risk factors in observational studies is hampered by the challenge in separating epilepsy-related risk and treatment-related risk, and uncertainty in the epilepsy diagnosis. This study aimed to identify factors associated with risk of subsequent vascular disease in patients with video-EEG monitoring (VEM) confirmed epilepsy.

METHODS

We included patients with a diagnosis of epilepsy and nonepileptic disorders between January 1, 1995, and December 31, 2015. Incident cardiovascular, cerebrovascular, and peripheral vascular disease was determined by linkage to a state-wide hospital admissions database between 1st July 1994 and 28th February 2018. Incidence was compared with the general population.

RESULTS

1728 patients (59.7% female, median age 35 years) underwent VEM, and were followed up for a median of 9.2 years (range 2.2-22.9 years). Eight-hundred and thirty -two were diagnosed with epilepsy and 896 nonepileptic disorders. The incidence of cerebrovascular disease was higher in both patients with epilepsy (incidence rate ratio [IRR] 1.78, p = 0.001) and with nonepileptic disorders (IRR 1.61, p < 0.001) than in the general population. Patients who took valproic acid (VPA) were at a lower risk of vascular disease than those taking enzyme-inducing antiseizure medications (EIASM, subdistribution hazard ratio [SHR] 0.42, p = 0.013), and those taking neither VPA nor EIASM (SHR 0.47, p = 0.03). There was no difference in the incidence of vascular disease between patients with epilepsy and those without epilepsy (SHR 0.94, p = 0.766). Factors associated with increased risk included age (SHR 1.04, p < 0.001), male sex (SHR 1.50, p = 0.017), and smoking (SHR 1.68, p = 0.017).

SIGNIFICANCE

In this study, both patients with epilepsy and without epilepsy had increased vascular risk. This suggests that the increased risk may be in part due to factors not directly related to epilepsy, such as EIASM use and vascular risk factors.

SARS-CoV-2 Infection, Sex-Related Differences, and a Possible Personalized Treatment Approach with Valproic Acid: A Review

Sex differences identified in the COVID-19 pandemic are necessary to study. It is essential to investigate the efficacy of the drugs in clinical trials for the treatment of COVID-19, and to analyse the sex-related beneficial and adverse effects. The histone deacetylase inhibitor valproic acid (VPA) is a potential drug that could be adapted to prevent the progression and complications of SARS-CoV-2 infection. VPA has a history of research in the treatment of various viral infections. This article reviews the preclinical data, showing that the pharmacological impact of VPA may apply to COVID-19 pathogenetic mechanisms. VPA inhibits SARS-CoV-2 virus entry, suppresses the pro-inflammatory immune cell and cytokine response to infection, and reduces inflammatory tissue and organ damage by mechanisms that may appear to be sex-related. The antithrombotic, antiplatelet, anti-inflammatory, immunomodulatory, glucose- and testosterone-lowering in blood serum effects of VPA suggest that the drug could be promising for therapy of COVID-19. Sex-related differences in the efficacy of VPA treatment may be significant in developing a personalised treatment strategy for COVID-19.

Stroke Genetics: Discovery, Insight Into Mechanisms, and Clinical Perspectives

Stroke is the second leading cause of death worldwide and a complex, heterogeneous condition. In this review, we provide an overview of the current knowledge on monogenic and multifactorial forms of stroke, highlighting recent insight into the continuum between these. We describe how, in recent years, large-scale genome-wide association studies have enabled major progress in deciphering the genetic basis for stroke and its subtypes, although more research is needed to interpret these findings. We cover the potential of stroke genetics to reveal novel pathophysiological processes underlying stroke, to accelerate the discovery of new therapeutic approaches, and to identify individuals in the population who are at high risk of stroke and could be targeted for tailored preventative interventions.

Association of Valproic Acid Use With Post-Myocardial Infarction Heart Failure Development: A Meta-Analysis of Two Retrospective Case-Control Studies

BACKGROUND

Despite advances in treatments, myocardial infarction (MI) remains a significant cause of morbidity and mortality worldwide. Our team has previously shown that valproic acid (VPA) is cardio-protective when administered to rats post-MI. The aim of this study was to investigate the association of VPA use with post-MI heart failure (HF) development in humans.

METHODS

This study was a random effects meta-analysis of two retrospective case-control studies collected from electronic health record (Michigan Medicine) and claims data (OptumInsight). Cases with an active prescription for VPA at the time of their MI were matched 1:4 to controls not taking VPA at the time of their MI by multiple demographic and clinical characteristics. The primary outcome, time-to-HF development, was analyzed using the Fine-Gray competing risks model of any VPA prescription versus no VPA prescription. An exploratory analysis was conducted to evaluate the association of different VPA doses (≥1000 mg/day vs <1000 mg/day vs 0 mg/day VPA).

RESULTS

In total, the datasets included 1313 patients (249 cases and 1064 controls). In the meta-analysis, any dose of VPA during an MI tended to be protective against incident HF post-MI (HR = 0.87; 95% CI = 0.72-1.01). However, when stratified by dose, high-dose VPA (≥1000 mg/day) significantly associated with 30% reduction in risk for HF post-MI (HR = 0.70; 95% CI = 0.49-0.91), whereas low-dose VPA (<1000 mg/day) did not (HR = 0.95; 95% CI = 0.78-1.13).

CONCLUSION

VPA doses ≥1000 mg/day may provide post-MI cardio-protection resulting in a reduced incidence of HF.

The effects of valproate on serum leptin, insulin, and lipid levels in epileptic children

BACKGROUND

Weight gain is an important adverse effect of valproate (VPA) therapy. A number of mechanisms have been proposed for its pathophysiology. The aim of the present study is the evaluation of insulin, leptin and lipid levels in epileptic children on treatment with VPA.

METHODS

Thirty epileptic children treated with VPA, and 20 age-sex-matched healthy children, were enrolled in this study. Blood samples were taken and the body mass index was calculated for all of the subjects. Serum insulin, leptin, and lipid levels were compared between the two groups.

RESULTS

Leptin levels were significantly higher in the patient group (P = 0.009) whereas body mass index values were comparable. There was a positive correlation between leptin and body mass index among both patient (r = 0.464, P = 0.01) and control groups (r = 0.734, P = 0.0001). Total cholesterol and low-density lipoprotein (LDL) cholesterol levels were lower in VPA-treated epileptic children than the control group (P = 0.008; P = 0.003, respectively). No significant difference was determined in insulin levels between the two groups. A negative correlation was observed between plasma VPA level and total cholesterol and LDL cholesterol levels in the patient group (r = -0.380, P = 0.03, r = -0.474, P = 0.008, respectively).

CONCLUSION

This study demonstrated higher leptin levels in the patient group despite similar BMI values. Hence, it seems likely that VPA causes leptin resistance. Unlike other anti-epileptics, VPA does not produce an increase in serum cholesterol levels. On the contrary, lower levels of total and LDL cholesterol levels in VPA-receiving patients have been observed in our study.

Valproic Acid Decreases Endothelial Colony Forming Cells Differentiation and Induces Endothelial-to-Mesenchymal Transition-like Process

Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor is a widely used anticonvulsant drug. VPA is also under clinical evaluation to be employed in anticancer therapy, as an antithrombotic agent or a molecule to be used in the stem cells expansion protocols. Since endothelial colony forming cells (ECFC) has been identified as the human postnatal vasculogenic cells involved in thrombotic disorders and serve as a promising source of immature cell for vascular repair, objectives of the present study were to determine how VPA contributes to ECFC commitment and their angiogenic properties. We examined the effect of VPA on ECFC obtained from cord blood by evaluating colony number, proliferation, migration and their sprouting ability in vitro, as well as their in vivo vasculogenic properties. VPA inhibited endothelial differentiation potential from of cord blood derived stem cells associated with decreased proliferation and sprouting activity of cultured ECFC. VPA treatment significantly decreased the vessel-forming ability of ECFC transplanted together with mesenchymal stem cells (MSC) in Matrigel implants in nude mice model. Surprisingly, a microscopic evaluation revealed that VPA induces marked morphological changes from a cobblestone-like EC morphology to enlarged spindle shaped morphology of ECFC. RT-qPCR and a CD31/CD90 flow cytometry analysis confirmed a phenotypic switch of VPA-treated ECFC to mesenchymal-like phenotype. In conclusion, the pan-HDAC inhibitor VPA described for expansion of hematopoietic stem cells and very small embryonic like stem cells cannot be successfully employed for differentiation of endothelial lineage committed ECFC into functional endothelial cells. Our data also suggest that VPA based therapeutics may induce endothelial dysfunction associated with fibrosis that might induce thrombosis recurrence or venous insufficiency.

Risk of Cardiac Morbidities and Sudden Death in Patients With Epilepsy and No History of Cardiac Disease: A Population-Based Nationwide Study

OBJECTIVE

To investigate the impact of epilepsy on secondary cardiac morbidities and sudden death in patients with epilepsy.

PATIENTS AND METHODS

The present cohort study evaluated data obtained from a subset of adult patients listed in the Taiwan National Health Insurance Research Database with an International Classification of Diseases, Ninth Revision, diagnosis code of epilepsy from January 1, 1997, to December 31, 2013; the date of epilepsy diagnosis or antiepilepsy drug prescription was defined as the index date. Patients with cardiac disease prior to the index date were excluded, and the remaining patients were categorized into epilepsy and nonepilepsy groups. Frequency matching was performed to balance the covariates across groups for the comparison of outcomes. The development of myocardial infarction (MI) and arrhythmia and/or the occurrence of sudden death were the outcomes for evaluation. A Cox proportional hazards regression model and competing risk analysis were used to compare the risks of cardiac morbidities and sudden death between groups.

RESULTS

The final analysis included a total of 5411 patients with epilepsy and 21,644 participants without epilepsy. The epilepsy group had significantly higher risks for development of MI (hazard ratio [HR], 1.71; 95% CI, 1.62 to 1.81; P<.001) and arrhythmia (HR, 2.11; 95% CI, 1.97 to 2.25; P<.001) and the occurrence of sudden death (HR, 1.83; 95% CI, 1.53 to 2.18; P<.001) compared with the nonepilepsy group.

CONCLUSION

Our results indicate that the risks for development of MI and arrhythmia and the occurrence of sudden death were higher in patients with epilepsy. These findings support the hypothesis that epilepsy may lead to secondary cardiac dysfunction and increases the risk of sudden death.

The Association Between Vascular Inflammation and Depressive Disorder. Causality, Biomarkers and Targeted Treatment

Diabetes, obesity, atherosclerosis, and myocardial infarction are frequently co-morbid with major depressive disorder. In the current review, it is argued that vascular inflammation is a factor that is common to all disorders and that an endothelial dysfunction of the blood-brain barrier could be involved in the induction of depression symptoms. Biomarkers for vascular inflammation include a high plasma level of C-reactive protein, soluble cell-adhesion molecules, von Willebrand factor, aldosterone, and proinflammatory cytokines like interleukin-6 or tumor necrosis factor α. A further possible biomarker is flow-mediated dilation of the brachial artery. Treatment of vascular inflammation is expected to prevent or to reduce symptoms of depression. Several tentative treatments for this form of depression can be envisioned: eicosapentaenoic acid (EPA), valproate, Vagus-nerve stimulation, nicotinic α7 agonists, and agonists of the cannabinoid CB₂-receptor.

Increased risk of stroke and myocardial infarction in patients with epilepsy: A systematic review of population-based cohort studies

OBJECTIVE

The objective of the study was to review the current epidemiological evidence about the relationship between epilepsy and increased risk of cardio- and cerebrovascular events.

METHODS

We systematically searched MEDLINE (from inception to 19th October 2018) to identify population-based cohort studies evaluating the risk of subsequent stroke or myocardial infarction (MI) in patients with epilepsy without history of prior cerebrovascular disease in comparison with subjects without epilepsy.

RESULTS

A total of 16,641 records were screened, and 6 studies were included. Data on the risk of subsequent stroke and MI were provided by five and two studies, respectively. The adjusted hazard ratios (_adjHRs) of subsequent ischemic stroke for patients with epilepsy ranged from 1.09 (95% confidence interval (CI): 1.00-1.19) to 2.85 (95% CI: 2.49-3.26). Two studies assessing the incidence of hemorrhagic stroke showed an increased risk in patients with epilepsy (_adjHR: 3.30; 95% CI: 2.46-4.43 and _adjHR: 2.27; 95% CI: 1.80-2.85). The _adjHRs of subsequent MI ranged between 1.09 (95% CI: 1.00 to 1.19) and 1.48 (95% CI: 1.31-1.67). Age, hypertension, MI, diabetes, hyperlipidemia, and arteriosclerosis were significantly associated with the increase in stroke risk. A gradient between the antiepileptic drug (AED) dose and risk of subsequent stroke was found. In comparison with carbamazepine (CBZ), oxcarbazepine (OXC) was associated with an increased risk of stroke and valproate (VPA) with a reduction in risk of stroke and MI, whereas no significant associations with vascular disease were found for phenobarbital (PB), lamotrigine (LMT), phenytoin (PHT), clonazepam (CLZ), and clobazam (CLB).

CONCLUSIONS

Patients with epilepsy are at higher risk of subsequent stroke and MI in comparison with subjects without epilepsy. Although individual AEDs may carry different risks of cardio- and cerebrovascular disease, the clinical relevance of the metabolic effects of the enzyme-inducing AEDs is still uncertain. This article is part of the Special Issue "Seizures & Stroke".

Prognosis of poststroke epilepsy

This narrative review describes the literature on the impact of poststroke epilepsy (PSE) on stroke rehabilitation, quality of life (QoL), and mortality. Since severe stroke is a risk factor for PSE, it is not surprising that many studies report associations between PSE and poor functional outcome after stroke. However, some studies also report associations between PSE and outcome with multivariate analysis with adjustment for stroke severity, indicating that PSE may hamper rehabilitation. The mechanisms of such an effect remain unknown, and more studies are needed. Although the literature is heterogeneous, evidence is accumulating that PSE increases the risk of death. The majority of deaths are attributed to vascular disease, highlighting the importance of treating vascular risk in patients with PSE. Patients with PSE report poor QoL, especially if seizure freedom is not achieved. It is, therefore, worrying that although PSE is often considered easy to treat, many patients fail to achieve seizure freedom. Neurologists treating PSE should pursue seizure freedom in the same manner as all patients. With improved survival after stroke and raised ambitions in rehabilitation after stroke, the impact of PSE on life after stroke is a matter of growing importance. Future studies are needed on interventions that reduce the risk of vascular events in PSE. Qualitative studies describing obstacles experienced by patients with PSE are also currently lacking in the literature. This article is part of the Special Issue "Seizures & Stroke".

Antiepileptic Drug Use and the Risk of Stroke Among Community-Dwelling People With Alzheimer Disease: A Matched Cohort Study

Background People with Alzheimer disease ( AD ) are more predisposed to seizures than older people in general, and use of antiepileptic drugs ( AED s) is more frequent. AED use has been linked to a higher risk of vascular events in the general population; however, it is not evident whether the same risk exists in people with AD . We assessed the risk of stroke associated with incident AED use among people with AD . Methods and Results The MEDALZ (Medication Use and Alzheimer's Disease) cohort includes all Finnish people who received a clinically verified AD diagnosis (N=70718) from 2005 to 2011. People with previous strokes were excluded. For each incident AED user (n=5617) one nonuser was matched according to sex, age, and time since AD diagnosis. Analyses were conducted with Cox proportional hazards models and inverse probability of treatment weighting. Compared with nonuse, AED use was associated with an increased risk of stroke (inverse probability of treatment weighting hazard ratio ( HR ), 1.37; 95% confidence interval [CI], 1.07-1.74). The risk was strongest during the first 90 days (adjusted HR , 2.36; 95% CI , 1.25-4.47) of AED use. According to stroke type, the association was with ischemic strokes (inverse probability of treatment weighting HR , 1.34; 95% CI , 1.00-1.79) and hemorrhagic ones (inverse probability of treatment weighting HR , 1.44; 95% CI , 0.86-2.43). The stroke risk of users of older AED s did not differ from that of the users of newer AED s (adjusted HR , 1.04; 95% CI , 0.71-1.53). Conclusions AED use was related to an increased risk of stroke, regardless of AED type. Our results highlight caution in AED use in this vulnerable population.

Blood markers of cardiac stress after generalized convulsive seizures

OBJECTIVE

Generalized convulsive seizures (GCS) are associated with high demands on the cardiovascular system, thereby facilitating cardiac complications. To investigate occurrence, influencing factors, and extent of cardiac stress or injury, the alterations and time course of the latest generation of cardiac blood markers were investigated after documented GCS.

METHODS

Adult patients with refractory epilepsy who underwent video-electroencephalography (EEG) monitoring along with simultaneous one-lead electrocardiography (ECG) recordings were included. Cardiac biomarkers (cardiac troponin I [cTNI]; high-sensitive troponin T [hsTNT]; N-terminal prohormone of brain natriuretic peptide [NT-proBNP]; copeptin; suppression of tumorigenicity-2 [SST-2]; growth differentiation factor 15, [GDF-15]; soluble urokinase plasminogen activator receptor [suPAR]; and heart-type fatty acid binding protein [HFABP]) and catecholamines were measured at inclusion and at different time points after GCS. Periictal cardiac properties were assessed by analyzing heart rate (HR), HR variability (HRV), and corrected QT intervals(QTc).

RESULTS

Thirty-six GCS (6 generalized-onset tonic-clonic seizures and 30 focal to bilateral tonic-clonic seizures) were recorded in 30 patients without a history of cardiac or renal disease. Postictal catecholamine levels were elevated more than twofold. A concomitant increase in HR and QTc, as well as a decrease in HRV, was observed. Elevations of cTNI and hsTNT were found in 3 of 30 patients (10%) and 6 of 23 patients (26%), respectively, which were associated with higher dopamine levels. Copeptin was increased considerably after most GCS, whereas SST-2, HFABP, and GDF-15 displayed only subtle variations, and suPAR was unaltered in the postictal period. Cardiac symptoms did not occur in any patient.

SIGNIFICANCE

The use of more sensitive biomarkers such as hsTNT suggests that signs of cardiac stress occur in about 25% of the patients with GCS without apparent clinical symptoms. SuPAR may indicate clinically relevant troponin elevations. Copeptin could help to diagnose GCS, but specificity needs to be tested.

HDAC inhibitor valproic acid protects heart function through Foxm1 pathway after acute myocardial infarction

BACKGROUND

Epigenetic histone acetylation is a major event controlling cell functions, such as metabolism, differentiation and repair. Here, we aim to determine whether Valproic acid (VPA), a FDA approved inhibitor of histone deacetylation for bipolar disease, could protect heart against myocardial infarction (MI) injury and elucidate key molecular pathways.

METHODS

VPA was administrated to MI rats at different time points, onset and after MI injury. Echocardiography, histology, serum biology assays, and gene expression, inhibition, and over-expression were performed to characterize the systolic function, infarct size, gene and signaling pathways.

FINDINGS

VPA treatment reduced the infarct size by ~50% and preserved the systolic function of heart after acute MI in rats. Even 60 min after infarction, VPA treatment significantly decreased infarct size. Furthermore, long-term treatment of VPA markedly improved myocardial performance. VPA regulated gene expression essential for cell survival and anti-inflammatory response. Consequently, oxidative stress and cell death were notably reduced after VPA treatment. Moreover, Foxm1 was identified as a potential key target of VPA. Overexpression of Foxm1 provided similar heart protective effect to VPA treatment. Particularly, both VPA treatment and Foxm1 over-expression repressed inflammatory response after MI for heart protection. In contrast, inhibition of Foxm1 activity abolished the cardiac protective effect of VPA. VPA mediated CM protection through Foxm1 upregulation was also identified in a human ESC derived CM hypoxia/reperfusion system.

INTERPRETATION

VPA treatments significantly reduce cardiac damage after MI and the cardioprotective effect of VPA is likely mediated via Foxm1 pathway. FUND: This work was mainly supported by 1R01HL109054.

Myocardial infarction after epilepsy onset: A population-based retrospective cohort study

INTRODUCTION

Cardiovascular comorbidities of epilepsy such as hypertension, hyperlipidemia, and diabetes are associated with myocardial infarction (MI). Little data on the development of subsequent cardiovascular disease (CVD) in persons with epilepsy (PWE) are available, with inconsistent findings regarding the association between epilepsy and subsequent MI. A higher risk of MI among adults (without prior MI) following epilepsy diagnosis compared with that among controls was hypothesized.

METHODS

This retrospective cohort study used statewide hospital and emergency department (ED) encounter data from 2000-2013 for South Carolina residents aged >18 years without prior MI at the onset of epilepsy, or the first encounter for controls. Persons with epilepsy were compared with 1) persons with migraine (PWM), whose neurological condition has characteristics similar to epilepsy; and 2) persons with isolated lower extremity fracture (PWLF). Subsequent MI was defined as a diagnosis of MI after the first clinical encounter for epilepsy, migraine, or lower extremity fracture (LEF); the association was evaluated with Cox proportional hazard modeling methods.

RESULTS

In this study, 2.2% of PWE, 0.6% of PWM, and 1.2% of PWLF had a subsequent MI. Persons with epilepsy were significantly more likely to be non-Hispanic Black (NHB), be covered by Medicaid, and reside in a rural or low income area compared with PWM and PWLF. Specific cardiovascular disease risk factors were more prevalent in PWE than in PWM and PWLF. After adjustment, the hazard of subsequent MI in PWE was 48% higher than in PWM (hazard ratio (HR) = 1.48; 95% confidence intervals (CI) = 1.31-1.67) and 24% higher than in PWLF (HR = 1.24; 95% CI = 1.10-1.39). The hazard of MI increased with increasing age and number of additional comorbidities and was higher in males, those living in rural areas, and those with specific cardiovascular risk factors.

CONCLUSION

Persons with epilepsy had moderately elevated risk of subsequent MI compared with PWM or PWLF. The association between epilepsy and MI needs to be further investigated, and clinical care of PWE should include evaluation and management of risk factors for MI.

Dual mechanisms for the regulation of brain-derived neurotrophic factor by valproic acid in neural progenitor cells

Autism spectrum disorders (ASDs) are neurodevelopmental disorders that share behavioral features, the results of numerous studies have suggested that the underlying causes of ASDs are multifactorial. Behavioral and/or neurobiological analyses of ASDs have been performed extensively using a valid model of prenatal exposure to valproic acid (VPA). Abnormal synapse formation resulting from altered neurite outgrowth in neural progenitor cells (NPCs) during embryonic brain development has been observed in both the VPA model and ASD subjects. Although several mechanisms have been suggested, the actual mechanism underlying enhanced neurite outgrowth remains unclear. In this study, we found that VPA enhanced the expression of brain-derived neurotrophic factor (BDNF), particularly mature BDNF (mBDNF), through dual mechanisms. VPA increased the mRNA and protein expression of BDNF by suppressing the nuclear expression of methyl-CpG-binding protein 2 (MeCP2), which is a transcriptional repressor of BDNF. In addition, VPA promoted the expression and activity of the tissue plasminogen activator (tPA), which induces BDNF maturation through proteolytic cleavage. Trichostatin A and sodium butyrate also enhanced tPA activity, but tPA activity was not induced by valpromide, which is a VPA analog that does not induce histone acetylation, indicating that histone acetylation activity was required for tPA regulation. VPA-mediated regulation of BDNF, MeCP2, and tPA was not observed in astrocytes or neurons. Therefore, these results suggested that VPA-induced mBDNF upregulation was associated with the dysregulation of MeCP2 and tPA in developing cortical NPCs.

Psychotropic use and risk of stroke among patients with bipolar disorders: 10-year nationwide population based study

OBJECTIVES

To investigate the association between psychotropic agents (including antipsychotics, antidepressants and mood stabilizers) and risk of stroke among patients with bipolar disorders.

METHODS

We conducted a disease risk score-matched nested case-control study and identified patients with bipolar disorders (ICD-9 codes: 296.0x, 296.1x, 296.4x, 296.5x, 296.6x, 296.7x, 296.80, 296.81 or 296.89) from the National Health Insurance Research Database in Taiwan. Among them, we identified 1232 cases (981 were ischemic stroke and 251 were hemorrhagic stroke) and 5314 disease risk score-matched controls. Conditional logistic regression model equations were applied to determine the effect of psychotropic agents on stroke risk among patients with bipolar disorders.

RESULTS

The results indicated that overall use of psychotropic agents was associated with an increased risk of stroke (adjusted odds ratio [AOR] = 1.82; 95% confidence interval [CI]: 1.56-2.13). When classifying psychotropic agents into antipsychotics, antidepressants and mood stabilizers, respectively, a significant positive association was found for users of antipsychotics (AOR = 1.98; 95% CI = 1.53-2.56), antidepressants (AOR = 1.44; 95% CI = 1.16-1.79), and mood stabilizers (AOR = 1.89; 95% CI = 1.22-2.93). Combined use of psychotropic agents was associated with higher risk of stroke than monotherapy (AOR = 2.62; 95% CI = 1.98-3.45).

DISCUSSIONS

The results support our hypothesis that psychotropic use is associated with increased risk of stroke among patients with bipolar disorders. The stroke risks are higher among patients with polypharmacy than those with monotherapy. These findings warrant further investigation to confirm and replicate the findings using different methodologies and populations, and to mitigate residual confounding.

Sodium Valproate, a Histone Deacetylase Inhibitor, Is Associated With Reduced Stroke Risk After Previous Ischemic Stroke or Transient Ischemic Attack

Background and Purpose—

A variant in the histone deacetylase 9 (HDAC9) gene is associated with large artery stroke. Therefore, inhibiting HDAC9 might offer a novel secondary preventative treatment for ischemic stroke. The antiepileptic drug sodium valproate (SVA) is a nonspecific inhibitor of HDAC9. We tested whether SVA therapy given after ischemic stroke was associated with reduced recurrent stroke rate.

Methods—

Data were pooled from 3 prospective studies recruiting patients with previous stroke or transient ischemic attack and long-term follow-up: the South London Stroke Register, The Vitamins to Prevent Stroke Study, and the Oxford Vascular Study. Patients receiving SVA were compared with patients who received antiepileptic drugs other than SVA using survival analysis and Cox Regression.

Results—

A total of 11 949 patients with confirmed ischemic event were included. Recurrent stroke rate was lower in patient taking SVA (17 of 168) than other antiepileptic drugs (105 of 530; log-rank survival analysis P=0.002). On Cox regression, controlling for potential cofounders, SVA remained associated with reduced stroke (hazard ratio=0.44; 95% confidence interval: 0.3–0.7; P=0.002). A similar result was obtained when patients taking SVA were compared with all cases not taking SVA (Cox regression, hazard ratio=0.47; 95% confidence interval: 0.29–0.77; P=0.003).

Conclusions—

These results suggest that exposure to SVA, an inhibitor of HDAC, may be associated with a lower recurrent stroke risk although we cannot exclude residual confounding in this study design. This supports the hypothesis that HDAC9 is important in the ischemic stroke pathogenesis and that its inhibition, by SVA or a more specific HDAC9 inhibitor, is worthy of evaluation as a treatment to prevent recurrent ischemic stroke.

Risks of thromboembolism and bleeding with thromboprophylaxis in patients with atrial fibrillation: A net clinical benefit analysis using a ‘real world’ nationwide cohort study

It was the aim of this study to determine the efficacy and safety of vitamin K antagonists (VKAs) and acetylsalicylic acid (ASA) in patients with non-valvular atrial fibrillation (AF), with separate analyses according to predicted thromboembolic and bleeding risk. By individual levellinkage of nationwide registries, we identified all patients discharged with non-valvular AF in Denmark (n=132,372). For every patient, the risk of stroke and bleeding was calculated by CHADS2, CHA2DS2-VASc, and HAS-BLED. During follow-up, treatment with VKA and ASA was determined time-dependently. VKA consistently lowered the risk of thromboembolism compared to ASA and no treatment; the combination of VKA+ASA did not yield any additional benefit. In patients at high thromboembolic risk, hazard ratios (95% confidence interval) for thromboembolism were: 1.81 (1.73–1.90), 1.14 (1.06–1.23), and 1.86 (1.78–1.95) for ASA, VKA+ASA, and no treatment, respectively, compared to VKA. The risk of bleeding was increased with VKA, ASA, and VKA+ASA compared to no treatment, the hazard ratios were: 1.0 (VKA; reference), 0.93 (ASA; 0.89–0.97), 1.64 (VKA+ASA; 1.55–1.74), and 0.84 (no treatment; 0.81–0.88), respectively. There was a neutral or positive net clinical benefit (ischaemic stroke vs. intracranial haemorrhage) with VKA alone in patients with a CHADS2 score of ≥ 0, and CHA2DS2-VASc score of ≥ 1. This large cohort study confirms the efficacy of VKA and no effect of ASA treatment on the risk of stroke/thromboembolism. Also, the risk of bleeding was increased with both VKA and ASA treatment, but the net clinical benefit was clearly positive, in favour of VKA in patients with increased risk of stroke/thromboembolism.

Epilepsy as a systemic condition: Link with somatic comorbidities

BACKGROUND

People with epilepsy have more concomitant medical conditions than the general population; these comorbidities play an important role in premature mortality. We sought to generate explanatory hypotheses about the co-occurrence of somatic comorbidities and epilepsy, avoiding causal and treatment-resultant biases.

METHODS

We collected clinical, demographic and somatic comorbidity data for 2016 consecutive adults with epilepsy undergoing assessment at a tertiary centre and in 1278 people with epilepsy in the community. Underlying causes of epilepsy were not classed as comorbidities.

RESULTS

Somatic comorbidities were more frequent in the referral centre (49%) where people more frequently had active epilepsy than in the community (36%). Consistent risk factors for comorbidities were found in both cohorts. Using multivariable ordinal regression adjusted for age, longer epilepsy duration and an underlying brain lesion were independently associated with a smaller burden of somatic conditions. The treatment burden, measured by the number of drugs to which people were exposed, was not an independent predictor. Shorter epilepsy duration was a predictor for conditions that conceivably harbour significant mortality risks.

CONCLUSIONS

Somatic comorbidities do not occur randomly in relation to epilepsy; having more severe epilepsy seems to be a risk factor. Independently from age, the early period after epilepsy onset appears to be at particular risk, although it is not clear whether this relates to an early mortality or to a later decrease in the burden of comorbidities. These results suggest that, for some people, epilepsy should be considered a systemic condition not limited to the CNS.

4-phenylbutyrate and valproate treatment attenuates the progression of atherosclerosis and stabilizes existing plaques

BACKGROUND AND AIMS

Recent evidence suggests that endoplasmic reticulum (ER) stress signaling through glycogen synthase kinase (GSK)-3α/β is involved in the activation of pro-atherosclerotic processes. In this study, we examined the effects of small molecules that interfere with ER stress-GSK3α/β signaling on the progression and regression of atherosclerosis in a mouse model.

METHODS

To examine atherosclerotic progression, low-density lipoprotein receptor deficient (Ldlr^-/-) mice were placed on a high-fat diet (HFD) and treated with the chemical chaperone, 4-phenylbutyrate (4PBA, 3.8  g/L drinking water), or the GSK3α/β inhibitor, valproate (VPA, 625 mg VPA/kg diet), for 10 weeks. To examine potential effects on atherosclerotic regression, 4 week old Ldlr^-/- mice were placed on a HFD for 16 weeks. Subsets of mice were harvested at this time or switched to a chow (low fat) diet, or a chow diet with 4PBA or VPA treatment for 4 weeks.

RESULTS

In the progression model, the 4PBA- and VPA-treated mice had significantly reduced lesion and necrotic core size. Treatments had no effect on metabolic parameters, including plasma and hepatic lipid levels, or plaque composition. In the regression model, mice with 4PBA or VPA treatment showed no alterations in lesion size, but the lesions had significantly smaller necrotic cores, increased vascular smooth muscle cell content, and increased collagen content. These features are consistent with more stable plaques.

CONCLUSIONS

The pharmacological attenuation of ER stress or inhibition of GSK3α/β impedes the development of atherosclerosis in Ldlr^-/- mice and appears to promote the stabilization of existing lesions.

Pre-stroke seizures: A nationwide register-based investigation

PURPOSE

The relationship between cerebrovascular disease and seizures is clearly illustrated by poststroke epilepsy. Seizures can also be the first manifestation of cerebrovascular disease and case-control studies have demonstrated that seizures carry an increased risk of subsequent stroke. Thus, seizures could serve as a marker for vascular risk that merits intervention, but more data is needed before proper trials can be conducted. The occurrence of pre-stroke seizures has not been assessed on a national scale. We asked what proportion of strokes in middle-aged and elderly patients was preceded by seizures.

METHODS

All patients over 60 years of age with first-ever stroke in 2005-2010 (n=92,596) were identified in the Swedish stroke register (Riksstroke) and cross-sectional data on a history of a first seizure or epilepsy diagnosis in the ten years preceding stroke were collected from national patient registers with mandatory reporting.

RESULTS

1372 patients (1.48%) had a first seizure or epilepsy diagnosis registered less than ten years prior to the index stroke. The mean latency between seizure and stroke was 1474days (SD 1029 days).

CONCLUSIONS

Seizures or epilepsy preceded 1.48% of strokes in patients >60years of age. Based on recent national incidence figures, 5-20% of incident cases of seizures or epilepsy after 60 years of age could herald stroke, depending on age group. These proportions are of a magnitude that merit further study on how to reduce the risk of stroke in patients with late-onset seizures or epilepsy.

The association between dementia and epilepsy: A systematic review and meta-analysis

OBJECTIVE

Dementia is among the top 15 conditions with the most substantial increase in burden of disease in the past decade, and along with epilepsy, among the top 25 causes of years lived with disability worldwide. The epidemiology of dementia in persons with epilepsy, and vice versa, is not well characterized. The purpose of this systematic review was to examine the prevalence, incidence, and reported risk factors for dementia in epilepsy and epilepsy in dementia.

METHODS

Embase, PsycINFO, MEDLINE, and the Cochrane databases were searched from inception. Papers were included if they reported the incidence and/or prevalence of dementia and epilepsy. Two individuals independently performed duplicate abstract and full-text review, data extraction, and quality assessment. Random-effects models were used to generate pooled estimates when feasible.

RESULTS

Of the 3,043 citations identified, 64 were reviewed in full text and 19 articles were included. The period prevalence of dementia ranged from 8.1 to 17.5 per 100 persons among persons with epilepsy (insufficient data to pool). The pooled period prevalence of epilepsy among persons with dementia was 5 per 100 persons (95% confidence interval [CI] 1-9) in population-based settings and 4 per 100 persons (95% CI 1-6) in clinic settings. There were insufficient data to report a pooled overall incidence rate and only limited data on risk factors.

SIGNIFICANCE

There are significant gaps in knowledge regarding the epidemiology of epilepsy in dementia and vice versa. Accurate estimates are needed to inform public health policy and prevention, and to understand health resource needs for these populations.

Trimetazidine potentiates the antiepileptic activity and ameliorates the metabolic changes associated with pentylenetetrazole kindling in rats treated with valproic acid

Oxidative stress is implicated in epileptogenesis as well as in the metabolic changes associated with increased risk of atherosclerotic vascular disease in epilepsy. The present work investigated the impact of the antioxidant trimetazidine (TMZ) on the antiepileptic activity of valproic acid (VPA) and on the metabolic and histological changes in hippocampal, aortic, and hepatic tissues associated with epilepsy and (or) VPA. Rats were divided into non-pentylenetetrazole (non-PTZ) group subdivided into control and VPA-treated groups, and PTZ-treated group subdivided into PTZ, PTZ/VPA, PTZ/TMZ, and PTZ/VPA + TMZ groups. VPA treatment in PTZ rats resulted in an antioxidant effect with improvement in oxidative stress, metabolic and histopathological changes induced by PTZ in hippocampus, aortic, and hepatic tissues. TMZ exhibited anticonvulsant activity and potentiated the anticonvulsant effect of VPA. Combination of TMZ with VPA induced a greater reduction in oxidative stress, improvement in the metabolic and histopathological changes compared to VPA treatment. In contrast, VPA administration in non-PTZ-treated rats induced a pro-oxidative effect, associated with metabolic and histopathological changes in aortic and hepatic tissues. These findings suggest that co-administration of TMZ with VPA in epilepsy might antagonize not only the oxidative stress associated with epilepsy but might also counteract a potential pro-oxidative effect of VPA.

Valproic acid selectively increases vascular endothelial tissue-type plasminogen activator production and reduces thrombus formation in the mouse

Essentials Stimulating endogenous fibrinolysis could be a novel antithrombotic strategy. The effect of valproic acid on endothelial tissue plasminogen activator in mice was investigated. Valproic acid increased tissue plasminogen activator expression in vascular endothelium. Valproic acid reduced fibrin deposition and thrombus formation after vascular injury.

SUMMARY

Background The endogenous fibrinolytic system has rarely been considered as a target to prevent thrombotic disease. Tissue-type plasminogen activator (t-PA) production is potently increased by histone deacetylase (HDAC) inhibitors in endothelial cells in vitro, but whether this translates into increased vascular t-PA production and an enhanced fibrinolytic capacity in vivo is unknown. Objectives To determine whether the HDAC inhibitor valproic acid (VPA) stimulates production of t-PA in the vasculature of mice, and whether VPA pretreatment affects fibrin deposition and clot formation after mechanical vessel injury. Methods Mice were injected with VPA twice daily for up to 5 days. t-PA mRNA, and antigen expression in the mouse aorta and the circulating levels of t-PA were determined. Fibrin and thrombus dynamics after mechanical vessel injury were monitored with intravital confocal microscopy. Potential effects of VPA on platelets and coagulation were investigated. Results and Conclusions We found that VPA treatment increased vascular t-PA production in vivo and, importantly, that VPA administration was associated with reduced fibrin accumulation and smaller thrombi in response to vascular injury, but still was not associated with an increased risk of bleeding. Furthermore, we observed that higher concentrations of VPA were required to stimulate t-PA production in the brain than in the vasculature. Thus, this study shows that VPA can be dosed to selectively manipulate the fibrinolytic system in the vascular compartment and reduce thrombus formation in vivo.

Changes in hormone and lipid levels in male patients with focal seizures when switched from carbamazepine to lacosamide as adjunctive treatment to levetiracetam: A small phase IIIb, prospective, multicenter, open-label trial

Treatment with enzyme-inducing antiepileptic drugs (AEDs) such as carbamazepine (CBZ) can lead to changes in reproductive, endocrine, and lipid parameters, resulting in clinical symptoms for some patients. Previous studies indicate that these changes can be reversed by switching to a nonenzyme-inducing AED. Lacosamide is a newer-generation AED, not known to induce or strongly inhibit cytochrome P450 (CYP450) enzymes. In this phase IIIb, prospective, multicenter, open-label, single-arm trial (NCT01375374), the serum concentrations of CYP-related reproductive hormones, thyroid hormones, and lipids were assessed in otherwise healthy male patients with focal seizures (N=11), before and after a switch from CBZ (600-1200mg/day at baseline) to lacosamide (target dose: 400mg/day by the end of titration) as adjunctive treatment to the nonenzyme-inducing AED levetiracetam (LEV, stable dosage of >1000mg/day throughout). Cross titration took place over 4weeks, followed by an 8-week maintenance period. Serum measurements were conducted at baseline and at the end of maintenance. The median serum sex-hormone-binding globulin (SHBG) concentration was towards the higher end of the normal range at baseline and decreased following the switch (61.7 to 47.5nmol/L, N=10, p=0.027 by Wilcoxon signed-rank test). Free androgen index (100×testosterone/SHBG) and free thyroxine serum concentration increased (25.4 to 36.4 and 13.0 to 14.9pmol/L, respectively, both N=10 and p=0.002). At baseline, the median progesterone serum concentration was below the normal range (0.7nmol/L), whereas median cholesterol and low-density lipoprotein concentrations were above the normal range (5.5 and 3.6mmol/L, respectively). By the end of maintenance, all measured parameters were within the normal range. The safety and tolerability profile of lacosamide was consistent with that observed in previous studies. Furthermore, antiseizure efficacy appeared to be maintained, suggesting that deinduction of CYP enzymes following a switch from CBZ to lacosamide as adjunctive therapy to LEV is feasible within 8weeks and is associated with normalization of serum parameters.

White Matter Hyperintensities on Brain Magnetic Resonance Imaging in People with Epilepsy: A Hospital-Based Study

AIMS

We aim to explore whether people with epilepsy have increased white matter hyperintensities (WMHs).

METHODS

Eligible patients were categorized into newly diagnosed epilepsy (NE) and chronic epilepsy (CE); the latter were subdivided to those treated with enzyme-inducing antiepileptic drugs (EIAEDs) with or without non-enzyme-inducing antiepileptic drugs (NEIAEDs) and those with NEIAEDs only. WMHs were measured using age-related white matter changes (ARWMC) scale and compared between patients and healthy control group. Higher scores indicate greater WMH changes. The strengths of associations were estimated as incidence rate ratios (IRRs) with 95% confidence interval (CI).

RESULTS

A total of 217 patients were included in the analysis, of whom 67 had NE, 45 had CE treated with NEIAEDs, and 105 had CE treated with EIAEDs. Age was positively associated with ARWMC score (IRR per year, 1.03; 95%CI, 1.03-1.04, P < 0.001). Compared with the healthy control group (n = 23), all patient groups had higher ARWMC score (P < 0.05). The difference was greatest in patients receiving EIAEDs (IRR, 2.13; 95%CI, 1.22-3.70, P = 0.007).

CONCLUSIONS

WMHs tended to be observed in people with epilepsy, especially in those treated with EIAEDs. People with epilepsy with white matter changes should be evaluated for stroke risk, particularly if they are receiving EIAEDs.

The rapid suicide protection of mood stabilizers on patients with bipolar disorder: A nationwide observational cohort study in Taiwan

BACKGROUND

The suicide rate is high among bipolar disorder (BD) patients. Previous studies have focused on the anti-suicidal effect of long-term treatment with mood stabilizers but less on the immediate preventive effects of interventions. The aim of the study was to evaluate the short-term and immediate anti-suicidal effects of mood stabilizers on recent-onset BD patients.

METHODS

The National Health Insurance Database (NHID) of Taiwan was used to perform a nationwide cohort observation study of suicide behaviors in bipolar disorder. All the recent-onset BD patients (ICD-9-CM code 296 except 296.2 and 296.3) diagnosed between 2000-2005 were collected (n=5091) and followed through 2009. The primary endpoint was the presence of a suicide code or the end of observation; exposure to mood stabilizers in the final month of observation was the independent variable.

RESULTS

The hazard ratios (HRs) of suicide-related events, completed suicide, and all-cause mortality were significantly lower for those treated with lithium, divalproex, or carbamazepine compared with no use in the last month (HRs of suicide-related events were 0.10, 0.14 and 0.10, respectively, and all-cause mortality HRs were 0.03; P<0.0001); there was no significant difference in HR between the mood stabilizers.

LIMITATIONS

The NIHD does not provide information on the severity, mood status, or treatment adherence of BD patients. Neither substance-related disorder nor personality disorder were included in the analysis. We focused on the effect of the final prescription time period, not the long-term protective effect.

CONCLUSIONS

The immediate recent use of any mood stabilizer significantly lowers the rate of death, suicide, or suicidal behavior in BD.

Illuminating drug action by network integration of disease genes: a case study of myocardial infarction

Drug discovery has produced many successful therapeutic agents; however, most of these drugs were developed without a deep understanding of the system-wide mechanisms of action responsible for their indications. Gene-disease associations produced by molecular and genetic studies of complex diseases provide great opportunities for a system-level understanding of drug activity. In this study, we focused on acute myocardial infarction (MI) and conducted an integrative network analysis to illuminate drug actions. We integrated MI drugs, MI drug interactors, drug targets, and MI disease genes into the human interactome and showed that MI drug targets are significantly proximate to MI disease proteins. We then constructed a bipartite network of MI-related drug targets and MI disease proteins and derived 12 drug-target-disease (DTD) modules. We assessed the biological relevance of these modules and demonstrated the benefits of incorporating disease genes. The results indicate that DTD modules provide insights into the mechanisms of action of MI drugs and the cardiovascular (side) effects of non-MI drugs.

Comparative case-control study of homocysteine, vitamin B12, and folic acid levels in patients with epilepsy

INTRODUCTION

Increased blood homocysteine levels are a known cardiovascular risk factor. Epileptic patients on long-term treatment with antiepileptic drugs may present higher homocysteine levels and, consequently, a potential increase in cardiovascular risk.

MATERIAL AND METHODS

We conducted an observational case-control study to compare plasma levels of homocysteine, folic acid, and vitamin B₁₂.

RESULTS

Our study included a total of 88 subjects: 52 patients with epilepsy and 36 controls. Epileptic patients showed higher homocysteine levels (P=.084) and lower levels of folic acid (P<.05).

CONCLUSION

Homocysteine levels should be monitored in epileptic patients on long-term treatment with antiepileptic drugs. We suggest starting specific treatment in patients with high homocysteine levels.

Cognitive deterioration in adult epilepsy: Does accelerated cognitive ageing exist?

A long-standing concern has been whether epilepsy contributes to cognitive decline or so-called 'epileptic dementia'. Although global cognitive decline is generally reported in the context of chronic refractory epilepsy, it is largely unknown what percentage of patients is at risk for decline. This review is focused on the identification of risk factors and characterization of aberrant cognitive trajectories in epilepsy. Evidence is found that the cognitive trajectory of patients with epilepsy over time differs from processes of cognitive ageing in healthy people, especially in adulthood-onset epilepsy. Cognitive deterioration in these patients seems to develop in a 'second hit model' and occurs when epilepsy hits on a brain that is already vulnerable or vice versa when comorbid problems develop in a person with epilepsy. Processes of ageing may be accelerated due to loss of brain plasticity and cognitive reserve capacity for which we coin the term 'accelerated cognitive ageing'. We believe that the concept of accelerated cognitive ageing can be helpful in providing a framework understanding global cognitive deterioration in epilepsy.

A reduced risk of stroke with lithium exposure in bipolar disorder: a population-based retrospective cohort study

OBJECTIVES

The risk of stroke is increased in patients with bipolar disorder. Lithium exhibits neuroprotective effects but the association between lithium use and the risk of stroke is unknown.

METHODS

A population-based retrospective cohort study was conducted by utilizing the National Health Insurance Research Database in Taiwan. Subjects who had first been diagnosed with bipolar disorder between 2001 and 2006 were identified. A propensity score (PS) for receiving lithium was calculated with variables of age, gender, and comorbidities. The patients with bipolar disorder receiving lithium within the period from diagnosis through to December 2011 were designated as the lithium group (n = 635). A 1:2 ratio was used to select PS-matched subjects with bipolar disorder without lithium use (n = 1,250). Multivariate Cox proportional hazards regression models were used to explore the association, rather than causal inference, of lithium exposure and the risk of stroke.

RESULTS

Of the 1,885 subjects, 86 (4.6%) experienced stroke, including 2.8% of the lithium group and 5.4% of the non-lithium group. Lithium use was associated with a significantly reduced risk of stroke [hazard ratio (HR) = 0.39, 95% confidence interval (CI): 0.22-0.68]. Reduced risks of stroke were also associated with the highest cumulative lithium dose [≥720 defined daily dose (DDD), HR = 0.25, 95% CI: 0.10-0.59], the longest cumulative exposure period (≥720 days, HR = 0.20, 95% CI: 0.06-0.64), and the highest exposure rate (≥2 DDD/day, HR = 0.39, 95% CI: 0.21-0.70).

CONCLUSIONS

Lithium use was significantly related to a reduced risk of stroke in patients with bipolar disorder.

Antiepileptic drugs and the risk of ischaemic stroke and myocardial infarction: a population-based cohort study

OBJECTIVES

Hepatic enzyme-inducing antiepileptic drugs (AEDs) increase serum lipid levels and other atherogenic markers via the induction of cytochrome P450 and may therefore increase the risk of vascular events. We sought to assess the risk of ischaemic stroke and myocardial infarction (MI) according to AED enzymatic properties.

DESIGN

Population-based cohort study with nested case-control analysis.

SETTING

650 general practices in the UK contributing to the Clinical Practice Research Datalink.

PARTICIPANTS

A cohort of 252,407 incident AED users aged 18 or older between January 1990 and April 2013. For each case of ischaemic stroke or MI, up to 10 controls were randomly selected among the cohort members in the risk sets defined by the case and matched on age, sex, indication for AED, calendar time and duration of follow-up.

INTERVENTIONS

Current use of enzyme-inducing and enzyme-inhibiting AEDs compared with non-inducing AEDs.

PRIMARY OUTCOME MEASURES

Incidence rate ratios (RRs) of ischaemic stroke and MI.

RESULTS

5069 strokes and 3636 MIs were identified during follow-up. Inducing AEDs use was associated with a small increased risk of ischaemic stroke (RR=1.16, 95% CI 1.02 to 1.33) relative to non-inducing AEDs, most likely due to residual confounding. However, current use of inducing AEDs for ≥ 24 months was associated with a 46% increased risk of MI (RR=1.46, 95% CI 1.15 to 1.85) compared with the same duration of non-inducing AED, corresponding to a risk difference of 1.39/1000 (95% CI 0.33 to 2.45) persons per year. Current use of inhibiting AED was associated with a decreased risk of MI (RR=0.81, 95% CI 0.66 to 1.00).

CONCLUSIONS

The use of enzyme-inducing AEDs was not associated with an increased risk of ischaemic stroke; a small increase of MI with prolonged use was observed. In contrast, use of inhibiting AEDs was associated with a decreased risk of MI.

Stroke after adult-onset epilepsy: a population-based retrospective cohort study

BACKGROUND

Earlier studies indicate a higher risk of subsequent stroke in PWE aged ≥60. However, little is known of the incidence of subsequent stroke in people with epilepsy (PWE) aged 35 through 60. We determined the risk factors that increase the incidence of stroke following adult-onset epilepsy in a large statewide population over a 10-year period.

METHODS

South Carolina hospital discharge and emergency department (ED) data from 2000 to 2011 were used. The study was limited to persons aged ≥35years without prior stroke. Cases included patients diagnosed with epilepsy who were hospitalized or visited the ED. Controls were people with an isolated fracture of the lower extremity without any history of epilepsy or seizure disorders, presumed to approximate the health status of the general population. Epilepsy, fracture, stroke, and comorbid conditions were ascertained by diagnostic codes from health-care encounters. Only persons having stroke occurring ≥6months after the onset of epilepsy or after the first clinical encounter for controls were included. Cox proportional hazards modeling was performed to determine the risk of stroke.

RESULTS

There were 21,035 cases with epilepsy and 16,638 controls who met the inclusion criteria. Stroke incidence was 2.5 times higher following adult-onset epilepsy (6.3%) compared with controls (2.5%). After adjusting for comorbidities and other factors, cases with epilepsy showed a 60% higher risk of stroke (HR=1.6; 95% CI: 1.42-1.80) compared with controls. Nearly half of the strokes in cases with epilepsy occurred in those with first diagnosis between ages 35 and 55. Somatic comorbidities associated with increased risk of stroke were more prevalent in cases with epilepsy than controls yet similar in both groups with stroke. Risk of stroke increased with increasing age in both groups. However, the risk of stroke in cases with epilepsy increased faster and was similar to that in controls who were ≥10years older.

CONCLUSION

Adult-onset epilepsy at age 35 and older warrants consideration for occult cerebrovascular disease as an etiology of the epilepsy, which may also increase the risk of subsequent stroke. Somatic comorbidities frequently associated with epilepsy include comorbid conditions that share the same underlying pathology with stroke (i.e., hypertension, hyperlipidemia, myocardial infarction, diabetes, and arteriosclerosis). This increased risk of stroke in patients with adult-onset epilepsy should dictate the evaluation and management of stroke risk factors to prevent stroke.