Leptin and insulin homeostasis in epilepsy: relation to weight adverse conditions

Deferasirox exerts anti-epileptic effects by improving brain iron homeostasis via regulation of ITPRIP

Epilepsy constitutes a global health concern, affecting millions of individuals and approximately one-third of patients exhibit drug resistance. Recent investigations have revealed alterations in cerebral iron content in both epilepsy patients and animal models. However, the extant literature lacks a comprehensive exploration into the ramifications of modulating iron homeostasis as an intervention in epilepsy. This study investigated the impact of deferasirox, a iron ion chelator, on epilepsy. This study unequivocally substantiated the antiepileptic efficacy of deferasirox in a kainic acid-induced epilepsy model. Furthermore, deferasirox administration mitigated seizure susceptibility in a pentylenetetrazol-induced kindling model. Conversely, the augmentation of iron levels through supplementation has emerged as a potential exacerbating factor in the precipitating onset of epilepsy. Intriguingly, our investigation revealed a hitherto unreported discovery: ITPRIP was identified as a pivotal modulator of excitatory synaptic transmission, regulating seizures in response to deferasirox treatment. In summary, our findings indicate that deferasirox exerts its antiepileptic effects through the precise targeting of ITPRIP and amelioration of cerebral iron homeostasis, suggesting that deferasirox is a promising and novel therapeutic avenue for interventions in epilepsy.

Changes in the Dentate Gyrus Gene Expression Profile Induced by Levetiracetam Treatment in Rats with Mesial Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) is one of the most common forms of focal epilepsy. Levetiracetam (LEV) is an antiepileptic drug whose mechanism of action at the genetic level has not been fully described. Therefore, the aim of the present work was to evaluate the relevant gene expression changes in the dentate gyrus (DG) of LEV-treated rats with pilocarpine-induced TLE. Whole-transcriptome microarrays were used to obtain the differential genetic profiles of control (CTRL), epileptic (EPI), and EPI rats treated for one week with LEV (EPI + LEV). Quantitative RT-qPCR was used to evaluate the RNA levels of the genes of interest. According to the results of the EPI vs. CTRL analysis, 685 genes were differentially expressed, 355 of which were underexpressed and 330 of which were overexpressed. According to the analysis of the EPI + LEV vs. EPI groups, 675 genes were differentially expressed, 477 of which were downregulated and 198 of which were upregulated. A total of 94 genes whose expression was altered by epilepsy and modified by LEV were identified. The RT-qPCR confirmed that LEV treatment reversed the increased expression of Hgf mRNA and decreased the expression of the Efcab1, Adam8, Slc24a1, and Serpinb1a genes in the DG. These results indicate that LEV could be involved in nonclassical mechanisms involved in Ca2+ homeostasis and the regulation of the mTOR pathway through Efcab1, Hgf, SLC24a1, Adam8, and Serpinb1a, contributing to reduced hyperexcitability in TLE patients.

Association of Long-term Antiseizure Medication Use and Incident Type 2 Diabetes Mellitus

BACKGROUND AND OBJECTIVES

Diabetes mellitus (DM) contributes significantly to metabolic syndrome and cardiovascular events, and it may be a comorbidity of epilepsy. The objective of this study was to investigate whether long-term antiseizure medication (ASM) use is associated with the risk of developing type 2 diabetes.

METHODS

We analyzed data from the Chang Gung Research Database. Patients aged ≥45 years who received ASM treatment from January 2001 to May 2019 were identified. Patients with DM-associated diseases and short-term ASM use were excluded. The patients were classified into nonenzyme interaction, enzyme-inducing, enzyme-inhibiting, and mixed ASM groups. The rate of incident diabetes associated with individual ASM was further analyzed. Propensity score weighting was performed to balance between-group differences. Analyses were conducted with Cox proportional regression models and stabilized inverse probability of treatment weighting (IPTW). Hazard ratios (HRs) were calculated at 3, 4, 6, and 9 years after the index date and the end of follow-up.

RESULTS

A total of 5,103 patients were analyzed, of whom 474 took nonenzyme interaction ASMs, 1,156 took enzyme-inducing ASMs, 336 took enzyme-inhibiting ASMs, and 3,137 took mixed ASMs. During follow-up (39,248 person-years), 663 patients developed new-onset DM, and the prevalence was 13.0%. The incidence of DM plateaued at 6-9 years after ASM initiation. Enzyme-inhibiting ASMs were significantly associated with a higher HR starting at the third year and then throughout the study period. The HRs were 1.93 (95% CI 1.33-2.80), 1.85 (95% CI 1.24-2.75), and 2.08 (95% CI 1.43-3.03) in unadjusted, adjusted, and stabilized IPTW models, respectively, at the end of follow-up. The dosing of ASM did not increase the risk of DM, and none of the individual ASM analyses reached statistical significance.

DISCUSSION

The long-term use of enzyme-inhibiting ASMs was associated with an increased risk of incident DM, and the risk increased with the duration of treatment. These findings may guide the choice of drugs in those requiring long-term ASM therapy, particularly in high-risk individuals.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that enzyme-inhibiting ASMs were associated with an increased risk of developing DM compared with nonenzyme interaction ASMs.

Selected Biomarkers of Oxidative Stress and Energy Metabolism Disorders in Neurological Diseases

Neurological diseases can be broadly divided according to causal factors into circulatory system disorders leading to ischemic stroke; degeneration of the nerve cells leading to neurodegenerative diseases, such as Alzheimer's (AD) and Parkinson's (PD) diseases, and immune system disorders; bioelectric activity (epileptic) problems; and genetically determined conditions as well as viral and bacterial infections developing inflammation. Regardless of the cause of neurological diseases, they are usually accompanied by disturbances of the central energy in a completely unexplained mechanism. The brain makes up only 2% of the human body's weight; however, while working, it uses as much as 20% of the energy obtained by the body. The energy requirements of the brain are very high, and regulatory mechanisms in the brain operate to ensure adequate neuronal activity. Therefore, an understanding of neuroenergetics is rapidly evolving from a "neurocentric" view to a more integrated picture involving cooperativity between structural and molecular factors in the central nervous system. This article reviewed selected molecular biomarkers of oxidative stress and energy metabolism disorders such as homocysteine, DNA damage such as 8-oxo2dG, genetic variants, and antioxidants such as glutathione in selected neurological diseases including ischemic stroke, AD, PD, and epilepsy. This review summarizes our and others' recent research on oxidative stress in neurological disorders. In the future, the diagnosis and treatment of neurological diseases may be substantially improved by identifying specific early markers of metabolic and energy disorders.

Obesity and metabolic syndrome in patients with epilepsy, their relation with epilepsy control

Obesity and metabolic syndrome (MetS) are commonly observed in patients with epilepsy (PWE). Obesity and MetS are not only affecting the physical fitness and quality of life of these patients, rather antiepileptic drugs (AEDs) compliance and seizure control have also been affected. The objective of this review is to search the published literature regarding the prevalence of obesity and MetS in PWE and their relation to the response to AEDs. A comprehensive search using PubMed, Cochrane Databases, and Google Scholar was performed. A supplementary citation search was also conducted by analyzing the reference lists of identified sources. The initial search revealed 364 articles of potential relevance. The studies were analyzed in detail to obtain clinical information relevant to the objectives of the review. Many observational, case control studies, randomized control trials and few review articles were included for critical appraisal and review writing. Epilepsy is associated with MetS and obesity in all age groups. AEDs and lack of exercise are the chief causes while metabolic disturbances such as adiponectin, mitochondrial dysfunction, valproic acid (VPA)-associated insulin resistance, leptin deficiency, and endocrine dysfunction are also addressable factors. Although the risk of drug-resistant epilepsy (DRE) is also higher among obese PWE, the interaction between, MetS, and its components with DRE remain to be fully investigated. Further research is required to elucidate their interplay. Appropriate and careful selection of AEDs without compromising therapeutic efficacy supplemented by lifestyle counseling for exercise and diet should be practiced to avoid weight gain and potential DRE.

Identification of Adipocytokine Pathway-Related Genes in Epilepsy and Its Effect on the Peripheral Immune Landscape

Epilepsy is a multifactorial neurological disorder with recurrent epileptic seizures. Current research stresses both inflammatory and autoimmune conditions as enablers in the pathophysiological process of epilepsy. In view of the growing concern about the role of adipocytokines in antiepileptic and modulating immune responses, we aimed to investigate the relevance of the adipocytokine signaling pathway in the pathological process of epilepsy and its impacts on peripheral immune characteristics. In this study, expression profiles of 142 peripheral blood samples were downloaded from the Gene Expression Omnibus (GEO) database. Adipocytokine pathway-related genes were screened out by feature selection using machine-learning algorithms. A nomogram was then constructed and estimated for the efficacy of diagnosis. Cluster analysis was employed for the recognization of two distinct epilepsy subtypes, followed by an estimation of the immune cell infiltration levels using single-sample gene-set enrichment analysis (ssGSEA). The biological characteristics were analyzed by functional enrichment analysis. The aberrant regulation of adipocytokine signaling pathway was found in the peripheral blood of patients with epilepsy. Twenty-one differently expressed adipocytokine pathway-related genes were identified and five (RELA, PRKAB1, TNFRSF1A, CAMKK2, and CPT1B) were selected to construct a nomogram. Subsequent validations of its forecasting ability revealed that this model has satisfactory predictive value. The immune cell infiltration degrees, such as those of innate immune cells and lymphocytes, were found to significantly correlate to the levels of adipocytokine pathway-related genes. Additionally, 239 differentially expressed genes (DEGs) were identified and their biological functions were mainly enriched in the regulation of the immune response. In conclusion, our results confirmed the predictive value of adipocytokine pathway-related genes for epilepsy and explored their effects on immune infiltration, thereby improving our understanding of the pathogenesis of epilepsy and providing assistance in the diagnosis and treatment of epilepsy.

Atherogenic Risk Factors among Young Indian Adults with Epilepsy on Treatment with Phenytoin: Need for Novel Therapeutic Strategies

Background

Risk for the development of coronary heart disease and diabetes is found to be more among people with epilepsy especially when on treatment. Redox imbalance contributes to this risk especially in India as it is the diabetic capital of the world with higher prevalence of inflammation.

Objectives

The aim of this study was to evaluate atherogenic risk factors; dyslipidemia, oxidative stress, and systemic inflammation among young Indian adults with epilepsy on treatment with Phenytoin.

Material and Methods

Three groups of age and gender-matched young subjects were recruited. Group 1-Healthy control subjects, Group 2- Newly diagnosed epileptic young adults with recent epileptic seizures, Group 3- Epileptic adults on treatment with Phenytoin for more than 6 months were recruited.

Results

Dyslipidemia was found among the newly diagnosed epileptic subjects in comparison to healthy subjects. The LDL-cholesterol further increased, and HDL-cholesterol further decreased in the third group treated with Phenytoin. Body mass index of these treated epileptic subjects was more in comparison to healthy control. Low-grade inflammation as assessed by hsCRP and oxidative stress were significantly higher among the newly diagnosed epileptic subjects when compared to the healthy controls which further increased on treatment with phenytoin. We found dyslipidemia, oxidative stress, and low-grade inflammation among newly diagnosed epileptic subjects which further increased on treatment with Phenytoin for more than 6 months.

Conclusion

From this study, we conclude that dyslipidemia, oxidative stress and low-grade inflammation are identified among the newly diagnosed young adult Indian epileptic patients. Phenytoin treatment further augmented these complications.

Incidence, risk factors and outcomes of seizures occurring after craniotomy for primary brain tumor resection

Objective:

To determine the incidence, risk factors and outcomes of early post-craniotomy seizures.

Method:

This was a retrospective cohort study of all patients who underwent craniotomy for primary brain tumor resection (2002-2011) and admitted postoperatively to the intensive care unit. The patients were divided into 2 groups depending on the occurrence of seizures within 7 days.

Results:

One-hundred-ninety-three patients were studied: 35.8% had preoperative seizure history and 16.6% were on prophylactic antiepileptic drugs (AEDs). Twenty-seven (14%) patients had post-craniotomy seizures. The tumors were mostly meningiomas (63% for the post-craniotomy seizures group versus 58.1% for the other group; p=0.63) and supratentorial (92.6% for the post-craniotomy seizures versus 78.4% for the other group, p=0.09) with tumor diameter=3.7±1.5 versus 4.2±1.6 cm, (p=0.07). One (3.1%) of the 32 patients on prophylactic AEDs had post-craniotomy seizures compared with 12% of the 92 patients not receiving AEDs preoperatively (p=0.18). On multivariate analysis, predictors of post-craniotomy seizures were preoperative seizures (odds ratio, 2.62; 95% confidence interval, 1.12-6.15) and smaller tumor size <4 cm (odds ratio, 2.50; 95% confidence interval, 1.02-6.25). Post-craniotomy seizures were not associated with increased morbidity or mortality.

Conclusion:

Early seizures were common after craniotomy for primary brain tumor resection, but were not associated with worse outcomes. Preoperative seizures and smaller tumor size were independent risk factors.

The effects of valproate and topiramate use on serum insulin, leptin, neuropeptide Y and ghrelin levels in epileptic children

PURPOSE

Although some drugs used in the treatment of epilepsy are known to affect body weight, the hormonal factors responsible have not been sufficiently described. The purpose of this study was to compare insulin, leptin, neuropeptide Y and ghrelin levels in children with epilepsy receiving monotherapy with topiramate (TPM) and valproic acid (VPA), the drugs whose effects on body weight have been most discussed, with those of a control group.

METHOD

48 patients (25 VPA, 23 TPM) aged between 6 and 15.5 years, presenting to the Karadeniz Technical University Medical Faculty Pediatric Neurology Clinic, diagnosed with idiopathic epilepsy or location-related idiopathic epilepsy, and receiving VPA or TPM monotherapy for at least 6 months were included in the study. Twenty-five healthy subjects with similar demographic characteristics were enrolled as the control group. Blood samples were collected from the patient and control groups after fasting for at least 10-12 h and again 1 and 2 h postprandially. Body mass index (BMI) values were calculated for all cases. VPA levels, glucose, insulin, leptin, neuropeptide Y and ghrelin were investigated in all three separate blood samples.

RESULTS

Age, height, weight and BMI were similar between the patient and control groups. Significant weight gain was observed throughout treatment in the VPA group compared to the TPM group. High fasting and postprandial insulin levels were observed in the VPA group. VPA group leptin and neuropeptide Y (NPY) levels were also higher than in the TPM and control groups. No significant difference was determined in ghrelin levels in the patient groups compared to the controls.

CONCLUSION

Low blood sugar not being observed, even though insulin levels are high, after fasting and in the postprandial period in epileptic children receiving VPA is indicative of insulin resistance. The elevation in leptin and neuropeptide Y levels observed in the VPA group also suggest this.

Vestibular Function in Adults With Epilepsy of Unknown Etiology

OBJECTIVE

This study aimed to evaluate vestibular function in adults with chronic epilepsy of unknown etiology in the inter-ictal period.

BACKGROUND

Epilepsy is a chronic medical disorder. Life-long therapy may be required in one-third of patients. Epilepsy is associated with comorbid somatic conditions which impairs patients' quality of life.

METHODS

This cross-sectional study included 28 with generalized tonic clonic (GTC) convulsions and 14 and 3 with temporal (TLE) and frontal lobe (FLE) epilepsies with secondary generalization (all were on regular carbamazepine therapy) and 40 healthy control subjects. The patients' mean age was 34.97 ± 7.35 years and the duration of illness was 18.75 ± 7.99 years. All underwent videonystagmography (VNG).

RESULTS

Compared with controls, patients had frequent vestibular symptoms including dizziness (62.22%) (p = 0.0001) and sense of imbalance (44.44%) (p = 0.0001). Eleven patients (24.44%) had central vestibular dysfunction (p = 0.0001); 9 (20%) had mixed vestibular dysfunction and one (2.22%) had peripheral vestibular dysfunction (p = 0.0001). Abnormalities were observed in saccadic (44.4%) and pursuit (42.2%) eye movements, optokinetic nystagmus (42.2%) and positioning/positional (11.11%) and caloric (13.33%) testing. TLE and FLE were associated with more VNG abnormalities than GTC. No significant differences were observed in the demographic and clinical characteristics between patients with and without VNG abnormalities.

CONCLUSION

Vestibular manifestations are frequent in patients with epilepsy. This may be a result of the permanent damaging effect of chronic epilepsy on the vestibular cortical areas and/or a toxic effect from prolonged carbamazepine therapy on the peripheral and central vestibular systems.

Weight gain in children on oxcarbazepine monotherapy

BACKGROUND

Studies of the effect of oxcarbazepine (OXC) on body growth of children with epilepsy are rare and their results are controversial. To the contrary, many studies have shown significant weight gain following valproate (VPA) treatment.

PURPOSE

To prospectively evaluate the effect of OXC monotherapy on growth patterns of children with epilepsy and compare it with the effect of VPA monotherapy.

METHOD

Fifty-nine otherwise healthy children, aged 3.7-15.9 years, with primary generalized, partial or partial with secondary generalization seizure disorder, were included in the study. Twenty six children were placed on OXC and thirty three on VPA monotherapy. Body weight (BW), height and body mass index (BMI) as well as their standard deviation scores (SDS), were evaluated prior to as well as 8 months post initiation of OXC or VPA therapy.

RESULTS

Eight months post OXC-treatment, BW, SDS-BW, BMI and SDS-BMI increased significantly. The increase was similar to that observed in the VPA group. An additional 15.4% of children in the OXC group and 21.2% in the VPA group became overweight or obese. The effect of both OXC and VPA therapy on linear growth did not reach statistical significance.

CONCLUSION

Similarly to VPA, OXC monotherapy resulted in a significant weight gain in children with epilepsy. Careful monitoring for excess weight gain along with counseling on adapting a healthy lifestyle should be offered to children on OXC therapy.

Fatty liver in adults receiving antiepileptic medications: relationship to the metabolic risks

This study aimed to determine the frequency of fatty liver disease (FLD) induced by antiepileptic drugs (AEDs) and its relationship to the metabolic profile. This study included 130 patients (valproate or VPA = 75; carbamazepine or CBZ = 40; lamotrigine or LTG = 15). Liver ultrasonography (US) was done. Serum lipids, uric acid, free fatty acids (FFAs), glucose, insulin and leptin were measured. Compared to controls and patients on CBZ or LTG, higher BMI; TC, TG, LDL-c, uric acid, FFAs, glucose, insulin and leptin concentrations and enlarged liver lobes volume and span and insulin resistance (45%) were reported with VPA. With FLD, significant correlations were reported between BMI with leptin (r = 0.390;p < 0.01), insulin (r = 0.655;p < 0.001) and FFAs (r = 0.570;p < 0.001) and insulin with leptin (r = 0.355;p < 0.01). In multivariate analysis, with FLD, liver span was correlated with BMI (OR:4.50;95%CI:1.54-13.3,p = 0.01) and leptin concentrations (OR:2.55;95%CI:1.04-6.27,p = 0.045). We conclude that VPA therapy is a risk for FLD and is correlated with the associated adverse metabolic profile.

Markers of bone turnover in patients with epilepsy and their relationship to management of bone diseases induced by antiepileptic drugs

Data from cross-sectional and prospective studies revealed that patients with epilepsy and on long-term treatment with antiepileptic drugs (AEDs) are at increased risk for metabolic bone diseases. Bone diseases were reported in about 50% of patients on AEDs. Low bone mineral density, osteopenia/osteoporosis, osteomalacia, rickets, altered concentration of bone turnover markers and fractures were reported with phenobarbital, phenytoin, carbamazepine, valproate, oxcarbazepine and lamotrigine. The mechanisms for AEDs-induced bone diseases are heterogeneous and include hypovitaminosis D, hypocalcemia and direct acceleration of bone loss and/or reduction of bone formation. This article reviews the evidence, predictors and mechanisms of AEDs-induced bone abnormalities and its clinical implications. For patients on AEDs, regular monitoring of bone health is recommended. Prophylactic administration of calcium and vitamin D is recommended for all patients. Treatment doses of calcium and vitamin D and even anti-resorptive drug therapy are reserved for patients at high risk of pathological fracture.

Valproic acid and nonalcoholic fatty liver disease: A possible association?

Valproic acid (VPA) is one of the most prescribed drugs in children with newly diagnosed epilepsy. Weight gain and obesity have been observed as side effects of VPA. These are often linked with other metabolic disturbances such as development of insulin resistance, dyslipidemia, metabolic syndrome (MetS) and non-alcoholic fatty liver disease or nonalcoholic fatty liver disease (NAFLD). NAFLD refers to a group of liver disorders with marked hepatic steatosis. It is associated with an increased incidence of cardiovascular diseases and overall reduced life expectancy. NAFLD occurs in 20%-25% of the general population and it is known to be the most common cause of chronic liver disease. NAFLD therefore represents a major public health issue worldwide. This study reviews and summarizes relevant literature that supports the existence of an association between VPA therapy and the development of NAFLD in children. Long-term VPA-therapy appears to be associated with an increased risk of developing NAFLD. Further studies are needed to clarify the pathogenic mechanisms that lie behind this association and to standardize the options for the use of this drug in overweight patients and in those with risks for developing MetS and NAFLD.

Evaluation of penile vascular status in men with epilepsy with erectile dysfunction

PURPOSE

Erectile dysfunction (ED) is common in males with epilepsy, likely of multifactorial etiology, including possible systemic vascular comorbidities and medication effects. Here we examined male patients for the possibility of a vasculogenic element of ED.

METHODS

Research participants included 47 men with epilepsy (mean age=30.98 years; duration of illness=13.98 years) and 25 healthy matched men (mean age=30.36). Erectile function was assessed using the International Index of Erectile Function Questionnaire (IIEF-5). Penile blood flow was assessed using Duplex Ultrasonography (PDU) after intracavernous alprostadil injection. Penile peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI) were the functional parameters analyzed. Carotid artery intima media thickness (CA-IMT) was also measured.

RESULTS

Thirteen of the 47 men with epilepsy (23.40% versus 0% for controls) reported ED, and of these patients, 11 (84.62%) had abnormal PDU [PSV=28.23 ± 6.1cm/s, P=0.0001; EDV=2.22 ± 5.71 cm/s, P=0.004; RI=0.89 ± 0.22, P=0.071] suggesting vasculogic ED. Penile arterial insufficiency was identified in 5 (45.45%), while 6 (54.54%) had mixed arterial insufficiency and venous leak. Compared to patients with high PSV, patients with low PSV had lower IIED-5 scores, higher EDV, lower RI, higher diastolic blood pressure and higher CA-IMT values. There were no differences in depression, anxiety or concentrations of sex hormones. Significant correlations were evident between PDU variables and duration of illness, depression and anxiety scores and CA-IMT values. In multivariate analysis, the association between PDU parameters and CA-IMT values remained significant even after adjustment for other confounding variables.

CONCLUSIONS

Vasculogenic ED is frequent with epilepsy and its relationship to systemic atherosclerosis cannot be excluded.

Atherosclerosis in epilepsy: its causes and implications

Evidence from epidemiological, longitudinal, prospective, double-blinded clinical trials as well as case reports documents age-accelerated atherosclerosis with increased carotid artery intima media thickness (CA-IMT) in patients with epilepsy. These findings raise concern regarding their implications for age-accelerated cognitive and behavioral changes in midlife and risk of later age-related cognitive disorders including neurodegenerative processes such as Alzheimer's disease (AD). Chronic epilepsy, cerebral atherosclerosis, and age-related cognitive disorders including AD share many clinical manifestations (e.g. characteristic cognitive deficits), risk factors, and structural and pathological brain abnormalities. These shared risk factors include increased CA-IMT, hyperhomocysteinemia (HHcy), lipid abnormalities, weight gain and obesity, insulin resistance (IR), and high levels of inflammatory and oxidative stresses. The resulting brain structural and pathological abnormalities include decreased volume of the hippocampus, increased cortical thinning of the frontal lobe, ventricular expansion and increased white matter ischemic disease, total brain atrophy, and β-amyloid protein deposition in the brain. The knowledge that age-accelerated atherosclerosis may contribute to age-accelerated cognitive and behavioral abnormalities and structural brain pathologies in patients with chronic epilepsy represents an important research path to pursue future clinical and management considerations.

Weight change, genetics and antiepileptic drugs

Weight gain caused by antiepileptic drugs (AEDs) constitutes a serious problem in the management of people with epilepsy. AEDs associated with weight gain include sodium valproate, pregabalin and vigabatrin. Excessive weight gain can lead to non-compliance with treatment and to an exacerbation of obesity-related conditions. The mechanisms by which AEDs cause weight gain are not fully understood. It is likely that weight change induced by some AEDs has a genetic underpinning, and recent developments in DNA sequencing technology should speed the understanding, prediction and thus prevention of serious weight change associated with AEDs. This review focuses on the biology of obesity in the context of AEDs. Future directions in the investigations of the mechanism of weight change associated with these drugs and the use of such knowledge in tailoring the treatment of specific patient groups are explored.

Long-term valproate treatment increases brain neuropeptide Y expression and decreases seizure expression in a genetic rat model of absence epilepsy

The mechanisms by which valproate, one of the most widely prescribed anti-epileptic drugs, suppresses seizures have not been fully elucidated but may involve up-regulation of neuropeptide Y (NPY). We investigated the effects of valproate treatment in Genetic Absence Epilepsy Rats from Strasbourg (GAERS) on brain NPY mRNA expression and seizure control. GAERS were administered either valproate (42 mg.kg⁻¹ hr⁻¹) or saline continuously for 5 days. Electroencephalograms were recorded for 24 hrs on treatment days 1, 3 and 5 and the percentage of time spent in seizure activity was analysed. NPY mRNA expression was measured in different brain regions using qPCR. Valproate treatment suppressed seizures by 80% in GAERS (p<0.05) and increased NPY mRNA expression in the thalamus (p<0.05) compared to saline treatment. These results demonstrate that long-term valproate treatment results in an upregulation of thalamic expression of NPY implicating this as a potential contributor to the mechanism by which valproate suppresses absence seizures.

Trichostatin A modulates thiazolidinedione-mediated suppression of tumor necrosis factor α-induced lipolysis in 3T3-L1 adipocytes

In obesity, high levels of tumor necrosis factor α (TNFα) stimulate lipolysis in adipocytes, leading to hyperlipidemia and insulin resistance. Thiazolidinediones (TZDs), the insulin-sensitizing drugs, antagonize TNFα-induced lipolysis in adipocytes, thereby increasing insulin sensitivity in diabetes patients. The cellular target of TZDs is peroxisome proliferator-activated receptor γ (PPARγ), a nuclear receptor that controls many adipocyte functions. As a transcription factor, PPARγ is closely modulated by coregulators, which include coactivators and corepressors. Previous studies have revealed that in macrophages, the insulin-sensitizing effect of PPARγ may involve suppression of proinflammatory gene expression by recruiting the corepressor complex that contains corepressors and histone deacetylases (HDACs). Therefore, we investigated whether the corepressor complex is involved in TZD-mediated suppression of TNFα-induced lipolysis in 3T3-L1 adipocytes. Trichostatin A (TSA), a pan HDAC inhibitor (HDACI) that inhibits class I and II HDACs, was used to examine the involvement of HDACs in the actions of TZDs. TSA alone increased basal lipolysis and attenuated TZD-mediated suppression of TNFα-induced lipolysis. Increased basal lipolysis may in part result from class I HDAC inhibition because selective class I HDACI treatment had similar results. However, attenuation of TZD-mediated TNFα antagonism may be specific to TSA and related hydroxamate-based HDACI rather than to HDAC inhibition. Consistently, corepressor depletion did not affect TZD-mediated suppression. Interestingly, TSA treatment greatly reduced PPARγ levels in differentiated adipocytes. Finally, extracellular signal-related kinase 1/2 (ERK1/2) mediated TNFα-induced lipolysis, and TZDs suppressed TNFα-induced ERK phosphorylation. We determined that TSA increased basal ERK phosphorylation, and attenuated TZD-mediated suppression of TNFα-induced ERK phosphorylation, consistent with TSA's effects on lipolysis. These studies suggest that TSA, through down-regulating PPARγ, attenuates TZD-mediated suppression of TNFα-induced ERK phosphorylation and lipolysis in adipocytes.

Trichostatin A modulates thiazolidinedione-mediated suppression of tumor necrosis factor α-induced lipolysis in 3T3-L1 adipocytes

In obesity, high levels of tumor necrosis factor α (TNFα) stimulate lipolysis in adipocytes, leading to hyperlipidemia and insulin resistance. Thiazolidinediones (TZDs), the insulin-sensitizing drugs, antagonize TNFα-induced lipolysis in adipocytes, thereby increasing insulin sensitivity in diabetes patients. The cellular target of TZDs is peroxisome proliferator-activated receptor γ (PPARγ), a nuclear receptor that controls many adipocyte functions. As a transcription factor, PPARγ is closely modulated by coregulators, which include coactivators and corepressors. Previous studies have revealed that in macrophages, the insulin-sensitizing effect of PPARγ may involve suppression of proinflammatory gene expression by recruiting the corepressor complex that contains corepressors and histone deacetylases (HDACs). Therefore, we investigated whether the corepressor complex is involved in TZD-mediated suppression of TNFα-induced lipolysis in 3T3-L1 adipocytes. Trichostatin A (TSA), a pan HDAC inhibitor (HDACI) that inhibits class I and II HDACs, was used to examine the involvement of HDACs in the actions of TZDs. TSA alone increased basal lipolysis and attenuated TZD-mediated suppression of TNFα-induced lipolysis. Increased basal lipolysis may in part result from class I HDAC inhibition because selective class I HDACI treatment had similar results. However, attenuation of TZD-mediated TNFα antagonism may be specific to TSA and related hydroxamate-based HDACI rather than to HDAC inhibition. Consistently, corepressor depletion did not affect TZD-mediated suppression. Interestingly, TSA treatment greatly reduced PPARγ levels in differentiated adipocytes. Finally, extracellular signal-related kinase 1/2 (ERK1/2) mediated TNFα-induced lipolysis, and TZDs suppressed TNFα-induced ERK phosphorylation. We determined that TSA increased basal ERK phosphorylation, and attenuated TZD-mediated suppression of TNFα-induced ERK phosphorylation, consistent with TSA's effects on lipolysis. These studies suggest that TSA, through down-regulating PPARγ, attenuates TZD-mediated suppression of TNFα-induced ERK phosphorylation and lipolysis in adipocytes.

Weight gain following treatment with valproic acid: pathogenetic mechanisms and clinical implications

In the last years, a growing body of literature indicates an association between valproic acid therapy and weight gain. Weight gain during valproate treatment can be observed within the first 3 months of therapy and women seem to be more susceptible than men. The mechanism through which valproic acid may induce a weight gain is still controversial. The scope of this paper is to investigate the possible causal link between treatment and weight gain in epileptic patients. Systematic review of published epidemiological studies has been done in order to evaluate the real extent of this side effect of valproic acid and its clinical implications, such as an increased risk of insulin resistance and other secondary metabolic abnormalities. The knowledge of the potential of valproic acid to cause significant changes in body weight will help in appropriate selection and modification of antiepileptic therapy to minimize the risk for weight abnormalities. Measurements of body weight before initiation of valproic acid therapy should be done as part of the monitoring of patients with epilepsy to detect changes before there are serious adverse consequences; an increase of 2 kg of body weight after 1 month of treatment should imply considerations to change antiepileptic drug therapy.

The role of valproate in metabolic disturbances in bipolar disorder patients

BACKGROUND

Our previous report showed that patients with bipolar disorder (BD) have higher prevalence of hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL) and obesity in Taiwan. To confirm whether the metabolic disturbances is associated with the disease itself or the medications used for treating BD, we further compared the metabolic status among the valproate (VPA) treated BD patients, drug-free BD patients and healthy controls in Taiwan.

METHOD

This cross-sectional study included 119 healthy controls and 77 BD patients diagnosed according to the DSMIV-TR criteria in a university hospital. Among the diseased group, 25 remitted BD patients were drug-free (BD-F), and 52 of them were treated with VPA (BD-VPA). Their body mass index (BMI), plasma glucose levels and plasma lipid profiles were measured.

RESULTS

Plasma fasting glucose, insulin, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol (LDL) levels were significantly different among BD-VPA, the BD-F, and the healthy control groups. Valproate treatment was associated with significant higher plasma insulin, triglyceride, and BMI levels as well as lower fasting glucose and HDL levels. However, these biochemical indexes did not differ significantly between the BD-F and the healthy control groups.

CONCLUSION

These results provide further evidence that VPA treatment for BD may increase the risk of metabolic disturbances. The risk may be reduced after discontinuing VPA medication.

Increased insulin receptor expression in anterior temporal neocortex of patients with intractable epilepsy

The insulin receptor (IR) is a tyrosine kinase receptor that binds to insulin and plays pivotal roles in energy homeostasis, neuronal growth, neuronal survival, synaptic plasticity and cognitive function. The biological mechanisms of intractable epilepsy involve energy metabolism, neuron loss, neurogenesis and abnormal neural networks. Here, we evaluated the expression of the IR in the anterior temporal neocortex of patients with intractable epilepsy (IE) by immunohistochemistry, double-label immunofluorescence and immunoblotting. We compared these tissues against histologically normal anterior temporal lobes from individuals treated for post-trauma intracranial hypertension. We found that the IR was coexpressed with neuron-specific enolase (NSE) and that IR expression increased in the anterior temporal neocortex of epileptic patients. On the basis of the potential physiological effects of IR, our findings suggest that increased expression of the IR is a consequence of epileptic seizures and a cause of IE.

Efeitos endócrinos e metabólicos das drogas antiepilépticas

As drogas antiepilépticas (DAE) são utilizadas por um enorme contingente de pessoas em todo o mundo - tanto no tratamento das epilepsias como para outros fins - frequentemente por um longo tempo. Por essas razões, torna-se fundamental o conhecimento sobre os potenciais efeitos adversos desses medicamentos, muitos deles envolvendo vários aspectos hormonais e metabólicos que devem ser do conhecimento do endocrinologista. Nesta revisão, foi abordada a relação das DAE com anormalidades no metabolismo mineral ósseo, balanço energético e peso corporal, eixo gonadal e função tireoideana, além de ter sido revisado o papel terapêutico dessas medicações no tratamento da neuropatia diabética.

High prevalence of metabolic disturbances in patients with bipolar disorder in Taiwan

BACKGROUND

Both ethnicity and lifestyle may contribute to these abnormalities. High prevalences of obesity and metabolic disturbances in patients with bipolar disorder (BD) have been reported in western countries. However, reports about the prevalences in Asian countries remain scant.

METHOD

The cross-sectional study included 117 patients diagnosed as BD and treated with lithium (Li), valproate (VPA), or both at a university psychiatric outpatient clinic. Their body mass index and plasma levels of glucose and lipid were measured. The prevalence of metabolic syndrome was determined based on the IDF 2005 criteria.

RESULTS

13.7%, 36.8%, 53.0%, 18.6%, and 61.0% of the patients met the criteria for hyperglycemia, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), hypertension and large waist circumference, respectively. 33.9% of the patients met the IDF 2005 criterion for metabolic syndrome. The prevalence of metabolic abnormalities was significantly higher in patients who have been cotreated with second-generation antipsychotics (SGAs).

CONCLUSION

This study provides evidence of high prevalence of metabolic syndrome in BD patients in Taiwan. Such metabolic disturbances can increase morbidity and mortality. Further studies that focus on the underlying mechanisms and effective intervention strategies are warranted.

Epilepsy pharmacogenetics

Large interindividual variation in efficacy and adverse effects of anti-epileptic therapy presents opportunities and challenges in pharmacogenomics. Although the first true association of genetic polymorphism in drug-metabolizing enzymes with anti-epileptic drug dose was reported 10 years ago, most of the findings have had little impact on clinical practice so far. Most studies performed to date examined candidate genes and were focused on candidate gene selection. Genome-wide association and whole-genome sequencing technologies empower hypothesis-free comprehensive screening of genetic variation across the genome and now the main challenge remaining is to select and study clinically relevant phenotypes suitable for genetic studies. Here we review the current state of epilepsy pharmacogenetics focusing on phenotyping questions and discuss what characteristics we need to study to get answers.

Epilepsy and hormones: a critical review

Especially during growth, puberty, and menopause, profound changes including maturation of the growth hormone, sex steroid, and thyroid axes, as well as alterations in lipid homeostasis, cardiac integrity, and other enzyme systems, occur physiologically. With epilepsy, however, things are often changing, and there may be a complicated interplay between hormones, epilepsy, and antiepileptic drugs (AEDs). On the one hand, epilepsy itself possibly elicits diverse effects on different enzyme systems including sex steroids, the neuro-cardio-endocrine axis, and bone health. On the other hand, different AEDs are known to induce neuroendocrine changes (e.g., lipid metabolism) that may have deleterious consequences on health and well-being later in life. It is important for physicians and epileptologists to have in mind and to consider the endocrine effects induced by epilepsy itself or by a certain AED when starting antiepileptic therapy, especially when it is expected that long-term treatment will be necessary.

States of serum leptin and insulin in children with epilepsy: risk predictors of weight gain

BACKGROUND AND OBJECTIVES

Weight gain is an adverse metabolic effect in some children with epilepsy. The studies done to detect the effect of antiepileptic drugs and weight homeostatic hormones, insulin and leptin, were limited and controversial.

MATERIALS AND METHODS

We evaluated the serum leptin and insulin as predictors of weight gain in children receiving long-term treatment with valproate (VPA), carbamazepine (CBZ), lamotrigine (LTG). This study included 90 patients (treated: 70; untreated: 20). Serum lipid profile, insulin and leptin were measured.

RESULTS

BMI, serum leptin and insulin were significantly elevated in VPA compared with controls, untreated patients and those treated with CBZ, LTG and combined therapy with LTG. Girls on VPA had higher BMI and leptin levels than boys. With VPA, serum insulin was correlated with BMI (r=0.625, p<0.01), leptin (r=0.823, p<0.001), treatment duration (r=0.775, p<0.01) and VPA dose (r=0.975, p<0.0001). Serum leptin was correlated with age (r=0.980, p<0.0001), BMI (r=0.704, p<0.01), serum insulin (r=0.823, p<0.001), LDL-c (r=0.630, p<0.01), HDL-c (r=-0.880, p<0.001), treatment duration (r=0.770, p<0.01) and VPA dose (r=0.970, p<0.001). BMI is correlated with serum insulin, leptin, LDL-c (r=0.835, p<0.001) and HDL-c (r=-0.955, p<0.0001).

CONCLUSION

Hyperinsulinemia and hyperleptinemia are common with VPA and marked among epileptic children who gained weight suggesting states of insulin and leptin resistances. These alterations were not demonstrated with CBZ or LTG. The relationship between VPA, leptin and weight seems to be gender specific. Serum leptin may serve as a sensitive parameter for weight gain and reduction with intervention programs during follow-up of girls with epilepsy.

The aspects and mechanisms of cognitive alterations in epilepsy: the role of antiepileptic medications

Epilepsy is a major health problem. Several studies suggest a significant influence of epilepsy and its treatment on dynamic and functional properties of brain activity. Epilepsy can adversely affect mental development, cognition, and behavior. Epileptic patients may experience reduced intelligence, attention, and problems in memory, language, and frontal executive functions. Neuropsychological, functional, and quantitative neuroimaging studies revealed that epilepsy affect the brain as a whole. Mechanisms of epilepsy-related cognitive dysfunction are poorly delineated. Cognitive deficits with epilepsy may be transient, persistent, or progressive. Transient disruption of cognitive encoding processes may occur with paroxysmal focal or generalized epileptic discharges, whereas epileptogenesis-related neuronal plasticity, reorganization, sprouting, and impairment of cellular metabolism are fundamental determinants for progressive cognitive deterioration. Also antiepileptic drugs (AEDs) have differential, reversible, and sometimes cumulative cognitive adverse consequences. AEDs not only reduce neuronal irritability but also may impair neuronal excitability, neurotransmitter release, enzymes, and factors critical for information processing and memory. The present article serves as an overview of recent studies in adult and childhood epilepsy literatures present in PubMed that highlighted cognitive evaluation in epilepsy field (publications till 2008 were checked). We also checked the reference lists of the retrieved studies for additional reports of relevant studies, in addition to our experience in this field. Our search revealed that although the aspects of cognitive dysfunction, risk factors, and consequences have been explored in many studies; however, the mechanisms of contribution of epilepsy-related variables, including AEDs, to patients' cognition are largely unexplored. In this review, we discussed the differential effect of AEDs in mature and immature brains and the known mechanisms underlying epilepsy and AEDs adverse effects on cognition. The nature, timing, course, and mechanisms of cognitive alteration with epilepsy and its medications are of considerable clinical and research implications.