Bone mass and turnover in women with epilepsy on antiepileptic drug monotherapy

Vitamin D prophylaxis in persons with epilepsy?

Limited guidelines exist regarding osteoporosis prevention in the general population. Despite being a subject of controversy, the majority of research suggests that decreased vitamin D levels correlate with increased bone turnover, that is, an important risk factor for osteoporosis development. In most guidelines, daily vitamin D supplementation is recommended. In persons with epilepsy (PWE), the situation is more complex, as other factors can increase the chance of being vitamin D deficient. Currently, there are no internationally accepted guidelines regarding monitoring bone health in PWE. Our aim was to review the existing evidence in PWE on: (1) risk factors for vitamin D deficiency, (2) the identification of higher risk groups, and (3) the optimal ways to monitor bone health. Our narrative review shows that: (1) anti-seizure medication (ASM) use, especially enzyme-inducing ASM (EIASM) and valproic acid, is identified as an important risk factor for impaired bone health (e.g., increased risk for osteoporosis/fractures and/or vitamin D deficiency); (2) higher risk groups within the PWE population are present: intellectual or physical disability, institutionalized patients, puberty, early onset epilepsy and developmental epileptic encephalopathies, postmenopausal women, and use of multiple ASM/concomitant drugs (e.g. corticosteroids); and (3) a monitoring scheme can be suggested including laboratory tests, bone density measurements, managing of risk factors, and/or vitamin D supplementation. Overall, regular vitamin D measurement in PWE is a cost-effective and practical method for monitoring vitamin D deficiency, whereas in high-risk patients the combination of vitamin D measurement and bone densitometry is recommended. There is not enough evidence to advocate continuous vitamin D supplementation in all PWE. Children with epilepsy should receive the recommended daily intake of vitamin D for age and additional monitoring and supplementation if at higher risk of deficiency. There is a need for prospective trials exploring the potential benefit of vitamin D supplementation in PWE.

Sex steroid hormones and epilepsy: Effects of hormonal replacement therapy on seizure frequency of postmenopausal women with epilepsy-A systematic review

BACKGROUND AND PURPOSE

Hormonal replacement therapy (HRT) is used for symptomatic treatment of menopause. Some evidence suggests a proconvulsant effect of estrogen and an anticonvulsant role of progesterone. Thus, the use of exogenous sex steroid hormones might influence the course of epilepsy in peri- and postmenopausal women with epilepsy (WWE). We conducted a systematic review on the impact of HRT on the frequency of seizures of WWE.

METHODS

PubMed and Scopus were searched for articles published from inception until August 2022. Abstracts from the past 5 years from the European Academy of Neurology and European Epilepsy Congresses were also reviewed. Article reference lists were screened, and relevant articles were retrieved for consultation. Interventional and observational studies on WWE and animal models of estrogen deficiency were included. Critical appraisal was performed using the revised Cochrane risk-of-bias tool for randomized trials and ROBINS-E tool.

RESULTS

Of 497 articles screened, 13 studies were included, including three human studies. One cross-sectional study showed a decrease in seizure frequency in WWE using combined HRT, a case-control study showed an increase in comparison with controls, and a randomized clinical trial found a dose-dependent increase in seizure frequency in women with focal epilepsy taking combined HRT. Ten studies addressing the impact of HRT in rat models were also included, which showed conflicting results.

CONCLUSIONS

There is scarce evidence of the impact of HRT in WWE. Further studies should evaluate the harmful potential, and prospective registries are needed for monitoring this population.

Bone Turnover Markers: Basic Biology to Clinical Applications

Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.

Impact of carbamazepine on vitamin D levels: A meta-analysis

PURPOSE

There are longstanding concerns about the impact of enzyme-inducing anti-seizure medications (ASMs) on vitamin D, an important molecule in both bone metabolism and inflammation pathways. The relationship between chronic use of carbamazepine and vitamin D levels has been studied, but no comprehensive review to inform practitioners and policymakers is currently available. We performed a meta-analysis on studies that measured 25-hydroxyvitamin D (25OHD) levels in persons taking carbamazepine to determine whether this drug significantly reduces circulating 25OHD.

PRINCIPAL RESULTS

From a literature search of the terms "carbamazepine" and "vitamin D", we identified 12 studies that measured 25OHD levels in persons on carbamazepine monotherapy groups and controls. Persons taking carbamazepine had significantly lower 25OHD levels than persons not taking carbamazepine. The average 25OHD levels of carbamazepine-treated patients across all studies was 21.8 ng/mL (IQR 15.4,26.0) whereas 25OHD levels of control subjects was 28.0 ng/mL (IQR 20.8,30.4). The weighted difference of means was 4.00 ng/mL of 25OHD. Neither age nor sex nor duration of carbamazepine therapy had a significant impact on this finding. The effect was similar irrespective of whether the comparator group consisted of healthy controls or epilepsy patients taking non-inducing medications.

MAJOR CONCLUSIONS

Carbamazepine use is associated with a reduction of 25OHD levels. In combination with other literature establishing the problematic metabolic effects of carbamazepine, this meta-analysis provides additional evidence in favor of the use of alternative ASMs as first-line agents. At minimum, vitamin D supplementation should be strongly considered for patients prescribed carbamazepine.

Vitamin D Metabolism and Guidelines for Vitamin D Supplementation

Vitamin D is essential for bone health and is known to be involved in immunomodulation and cell proliferation. Vitamin D status remains a significant health issue worldwide. However, there has been no clear consensus on vitamin D deficiency and its measurement in serum, and clinical practice of vitamin D deficiency treatment remains inconsistent. The major circulating metabolite of vitamin D, 25-hydroxyvitamin D (25(OH)D), is widely used as a biomarker of vitamin D status. Other metabolic pathways are recognised as important to vitamin D function and measurement of other metabolites may become important in the future. The utility of free 25(OH)D rather than total 25(OH)D needs further assessment. Data used to estimate the vitamin D intake required to achieve a serum 25(OH)D concentration were drawn from individual studies which reported dose-response data. The studies differ in their choice of subjects, dose of vitamin D, frequency of dosing regimen and methods used for the measurement of 25(OH)D concentration. Baseline 25(OH)D, body mass index, ethnicity, type of vitamin D (D₂ or D₃) and genetics affect the response of serum 25(OH)D to vitamin D supplementation. The diversity of opinions that exist on this topic are reflected in the guidelines. Government and scientific societies have published their recommendations for vitamin D intake which vary from 400-1000 IU/d (10-25 μg/d) for an average adult. It was not possible to establish a range of serum 25(OH)D concentrations associated with selected non-musculoskeletal health outcomes. To recommend treatment targets, future studies need to be on infants, children, pregnant and lactating women.

Valproic Acid Impacts the Growth of Growth Plate Chondrocytes

A range of bone abnormalities including short stature have been reported to be associated with the use of antiepileptic drugs (AEDs) in children. Exactly how AEDs impact skeletal growth, however, is not clear. In the present study, rat growth plate chondrocytes were cultured to study the effects of AEDs, including valproic acid (VPA), oxcarbazepine (OXA), levetiracetam (LEV), lamotrigine (LTG), and topiramate (TPM) on the skeletal growth. VPA markedly reduced the number of chondrocytes by apoptosiswhile other AEDs had no effect. The apoptosis associated noncleaved and cleaved caspase 3, and caspases were increased by exposure to VPA, which up-regulated cyclooxygenase 2 (COX-2) mRNA and protein levels likely through histone acetylation. The COX-2 inhibitor NS-398 attenuated the effects of VPA up-regulating COX-2 expression and decreased VPA-induced caspase 3 expression. The use of VPA in children should be closely monitored or replaced, where appropriate, by AEDs which do not apparently affect the growth plate chondrocytes.

Bone health in pediatric patients with neurological disorders

Patients with neurological disorders are at high risk of developing osteoporosis, as they possess multiple risk factors leading to low bone mineral density. Such factors include inactivity, decreased exposure to sunlight, poor nutrition, and the use of medication or treatment that can cause lower bone mineral density such as antiepileptic drugs, ketogenic diet, and glucocorticoids. In this article, mechanisms involved in altered bone health in children with neurological disorders and management for patients with epilepsy, cerebral palsy, and Duchenne muscular dystrophy regarding bone health are reviewed.

Treatment of Women With Epilepsy

PURPOSE OF REVIEW

This article provides the latest information to guide practitioners in counseling and treating women with epilepsy.

RECENT FINDINGS

There is an increasing body of literature on the multidirectional effects of sex hormones on seizure frequency and severity and of seizures altering areas of the brain involved in neuroendocrine function. Ongoing pregnancy outcome data from pregnancy registries and meta-analysis of observational studies have provided key information on the safety of using antiseizure medications during pregnancy and the risk to the fetus.

SUMMARY

In treating and counseling women with epilepsy from puberty to menopause, it is important to understand the complex interactions of sex hormones, seizures, and antiseizure medications on reproductive health and pregnancy outcomes.

An update on the problem of osteoporosis in people with epilepsy taking antiepileptic drugs

INTRODUCTION

Antiepileptic drugs (AEDs) have been associated with a negative impact on bone health. Comorbid disorders in patients with epilepsy may require drugs exerting a pro-osteoporotic effect, so a possibility of untoward interactions with AEDs is probable.

AREAS COVERED

This review discusses evidence related to the deteriorating influence of AEDs on bone, demonstrating generally stronger negative effects of conventional AEDs. Lamotrigine seems to be a safer AED in this regard. Further, literature data indicate that generally AEDs can lower the serum concentration of vitamin D. Importantly, pediatric patients are of greater risk of bone problems during therapy with AEDs, which is probably due to their effects on bone-forming processes.

EXPERT OPINION

Supplementation with vitamin D and calcium is frequently recommended in patients taking AEDs chronically. Whether to add a bisphosphonate remains an open question due to the limited data on this issue. A possibility of negative interactions exists between AEDs and other pro-osteoporotic drugs: glucocorticoids, proton pump inhibitors and aromatase inhibitors. Depression is a frequent comorbidity in patients with epilepsy. Clinical data indicate that antidepressant drugs may also increase the risk of fractures. Again, patients with epilepsy and depression may be exposed to a greater risk of osteoporosis.

Effect of Long-term Carbamazepine Therapy on Bone Health

Introduction:

Recent research reported that prolonged use of AET is associated with changes in bone metabolism, with consequent reduction in bone mineral density (BMD) and increased risk of fractures.

Objectives:

Therefore, the aim of our study was to investigate the effects of carbamazepine on serum levels of 25 -hydroxyvitamin D and on biomarker of bone formation and resorption (serum levels of osteocalcin).

Material and methods:

We measured serum levels of 25-OHD and osteocalcin (OCLN) in normal controls (n=30) and in epilepsy patients taking carbamazepine (CBZ) (n=50) in monotherapy for a period of at least twelve months. For each participant, mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry method.

Results:

The average value of vitamin D in serum was significantly lower in CBZ group than in control group (Vit D 17.03+12.86 vs. 32.03+6.99, p=0.0001). The average value of osteocalcin in serum was significantly higher in CBZ group than in control group (26.06+10.78 vs. 19.64+6, 54, p=0.004).BMD value in CBZ group was significantly lower than in control group (T. score CBZ: 0.08+1.38 vs. T. score control: 0.73+ 1.13, p=0.031; Z score CBZ:-0.05+1.17 vs. Z. score control: 0.55+0.79, p=0.015).

Conclusion:

AEDs are associated with bone disease, as evidenced by biochemical abnormalities and decreased BMD. Patients on long-term antiepileptic therapy, especially with enzyme-inducing agents, could benefit of routine measurement of biochemical markers of bone turnover, and BMD measurement as part of osteoporosis investigation.

Levetiracetam and lamotrigine effects as mono- and polytherapy on bone mineral density in epileptic patients

OBJECTIVE

The purpose of this study was to determine the effect of lamotrigine (LTG) and levetiracetam (LEV) as mono- and polytherapy on biochemical markers of bone turnover and bone mineral density in Egyptian adult patients with epilepsy.

METHODS

Forty-eight patients were divided into four groups: two received monotherapy of either LTG or LEV, and the other two groups received polytherapy comprising (valproate [VPA] + LTG or VPA + LEV). Thirty matched healthy participants were included in the study. Participants completed a nutritional and physical activity questionnaire. Biochemical markers of bone and mineral metabolism and bone mineral density of the lumbar spine were measured at baseline and at six months.

RESULTS

In the LEV monotherapy group, the bone formation markers showed a significant decrease in serum alkaline phosphatase and serum osteocalcin levels while the bone resorption marker showed a significant increase in urinary deoxypyridinoline levels. After six months of treatment, bone mineral density showed a significant decrease in all treated groups, while among monotherapy groups, this significant decrease was more prevalent in the LEV monotherapy group compared with the LTG monotherapy group. Furthermore, there was significant negative correlation between urinary deoxypyridinoline levels and bone mineral density in the LEV monotherapy group.

CONCLUSION

Using new generation antiepileptics, LEV monotherapies and polytherapy showed harmful effects on bone but LTG did not.

Discontinuation of carbamazepine due to concerns of long-term consequences of enzyme induction

Objective

Treatment with carbamazepine (CBZ), a potent enzyme inducer, is known to affect the lipid profile, steroid, and vitamin D metabolism. Consequently, it has been postulated that patients on CBZ should be switched to noninducing antiepileptic drugs (AEDs). However, little is known about the seizure outcome following a CBZ switch in seizure‐free patients. We aimed to address this issue using a controlled observational study design.

Methods

Fifty‐eight patients taking CBZ for focal epilepsy were assessed for discontinuing CBZ treatment due to concerns of long‐term adverse‐effects; 34 discontinued its therapy and 24 continued with CBZ. Six‐month seizure freedom was the primary end point. Furthermore, serum samples (total cholesterol (TC), low‐density lipoprotein (LDL), high‐density lipoprotein (HDL), triglycerides, sex hormone–binding globulin (SHBG), free testosterone, and 25‐hydroxyvitamin D levels from before and at least 3 months after discontinuation or continuation were obtained from all patients.

Results

Seizure‐free patients had a 5‐fold elevated odds of seizure recurrence if CBZ was discontinued (95% confidence interval [CI 0.51–49.3; p = 0.17). A significant decrease in serum levels of TC, LDL, HDL, and SHBG as well as a significant increase in that of free testosterone were found in the discontinuation group compared with those who continued CBZ. Nonsignificant changes in triglycerides and vitamin D levels were detected.

Significance

Discontinuation of CBZ in seizure‐free patients seems to carry a moderate, but legitimate, risk of relapse. Conversely, our results indicate that CBZ might have unfavorable effects on serum levels of TC, LDL, HDL, SHBG, and free testosterone.

Effects of the antiepileptic drugs topiramate and lamotrigine on bone metabolism in rats

Long-term treatment with antiepileptic drugs (AED) is associated with an elevated risk of bone fracture due to decreased bone mineral density (BMD). Phenytoin has been shown to affect bone metabolism adversely, whereas newly developed AEDs have not been studied. This study evaluated the effects of topiramate and lamotrigine on bone metabolism in rats. Five-week-old male Sprague-Dawley rats were treated orally with phenytoin (20 mg/kg), topiramate (5 or 20 mg/kg), or lamotrigine (2 or 10 mg/kg) daily for 12 weeks. Phenytoin reduced bone strength, measured by maximum load to failure of the femoral mid-diaphysis, along with reduced femur total BMD. Serum tartrate-resistant acid phosphatase-5b levels significantly increased after phenytoin treatment, while serum osteocalcin levels decreased after topiramate 20 mg/kg treatment. Furthermore, osteoblast surface and bone mineralizing surface were significantly lowered by topiramate. Lamotrigine treatment did not affect bone strength, BMD, or bone turnover. We demonstrated that phenytoin treatment significantly increased bone resorption and lowered BMD and bone strength. Since lamotrigine did not affect bone metabolism, it can be concluded that lamotrigine is safety medicine for bone health. Topiramate was associated with decreased bone formation, which may affect bone strength and BMD with chronic use. Thus, patients taking topiramate should be monitored for changes in BMD to avoid risk of fracture.

Epilepsy and vitamin D: a comprehensive review of current knowledge

Vitamin D has been considered as neurosteroid, and its pivotal role in neuroprotection, brain development, and immunomodulation has been noticed in studies; however, our knowledge regarding its role in neurological disorders is still developing. The potential role of vitamin D in the pathophysiology and treatment of epilepsy, as one the most prevalent neurological disorders, has received less attention in recent years. In this article, we review the possible relationship between vitamin D and epilepsy from different aspects, including the action mechanism of vitamin D in the central nervous system and ecological and epidemiological findings. We also present the outcome of studies that evaluated the level of vitamin D and the impact of administrating vitamin D in epileptic patients or animal subjects. We also review the current evidence on interactions between vitamin D and antiepileptic drugs.

Bone Metabolism Disorder in Epileptic Children

OBJECTIVE

There are frequent anti-epileptic drugs used in management of epilepsy. Anti-epileptic drugs may have some complications on bone and vitamin D metabolism. This study aimed to comparison the bone metabolism disorder in epileptic children with healthy child in Zahedan, eastern Iran from Jul 2014 to Jun 2015.

MATERIALS & METHODS

This case-control study was performed on bone metabolism disorder in epileptic children between 2014-2015. Forty epileptic children were enrolled based on accessibility scheme and 40 participants randomly selected for control group from those referred to the pediatric ward and clinic of Ali Ebn Abi Talib Hospital and Ali Asghar Clinic in Zahedan City, Sistan & Baluchestan Province, eastern Iran. Blood samples were collected from all participants to assess serum calcium, phosphorus, parathyroid hormone, magnesium, vitamin D, serum albumin, creatinine random urine.

RESULTS

Of 40 epileptic children, 23 (57.5%) and 17 (42.5%) were male and female respectively, The prevalence of lower mean vitamin D levels was 37.5% for patients compared to 12.5% for controls (chi-square=6.667 and P=0.010). Of 80 participants, 15 individuals had abnormal PTH levels detected of 2 and 13 for patients and control groups, respectively (chi-square =9.928 and P=0.002). Serum calcium and magnesium levels were comparable in both groups. The status of the parameters in the classification of normal and abnormal assessed based on number of medications intake resulted that number of medications intake had no effect on the status of the parameter.

CONCLUSION

The frequency of hyperparathyroidism and vitamin D deficiency is increased in epileptic children.

The transition from pediatric to adult care for youth with epilepsy: Basic biological, sociological, and psychological issues

Transition from pediatric to adult health care for adolescents with epilepsy is challenging for the patient, family, and health care workers. This paper is the first of three that summarize the main findings from the 2nd Symposium on Transition in Epilepsies, held in Paris from June 14-25, 2016. In this paper we describe five basic themes that have an important effect on transition. First, there are important brain changes in adolescence that leave an imbalance between risk taking and pleasure seeking behaviors and frontal executive function compared with adults. Second, puberty is a major change during the transition age. The three most important but separate neuroendocrine axes involved in puberty are gonadarche (activation of the gonads), adrenarche (activation of adrenal androgen production), and activation of the growth hormone-insulin like growth factor. Third, sexual debut occurs during the transition years, and at an earlier age in adolescents with epilepsy than controls. Adult sexual performance is often unsatisfactory. Although AED-induced alterations in sexual hormones and temporal lobe epilepsy may play a role in hyposexuality, depression, anxiety, and other social factors appear most important. Fourth, psychological development is very important with an evolution from an early stage (ages 10-13years) with concrete thinking, to a middle stage (ages 14-17) with analytic and more abstract introspective thinking, and then to a late stage (ages 18-21) with at least the beginnings of adult reasoning. Epilepsy may derail this relatively orderly progression. Adolescents with autistic spectrum disorder may present with severe behavior problems that are sometimes related to undiagnosed epilepsy. Fifth, bone health in adolescence is critical to establish adequate mineralization for all of adult life. While AED interference with Vitamin D metabolism is important, there is evidence that the effects of AEDs on bone are more complex and involve changes in remodeling. Hence, some non-inducing AEDs may have a significant effect on bone health. All five of these themes lead to recommendations for how to approach adolescents and young adults during transition and some specific interventions to achieve maximum long-term adult independence and quality of life.

Neuron subset-specific Pten deletion induces abnormal skeletal activity in mice

Individuals with a history of epilepsy are at higher risk for bone fractures compared to the general population. Although clinical studies support an association between low bone mineral density (BMD) and anti-seizure medications, little is known on whether a history of seizures is linked to altered bone health. Therefore, in this study we tested the hypothesis that bone mass, morphology, and bone mineralization are altered by seizures in genetically epileptic animals and in animals subjected to an episode of status epilepticus. In this study, we used NS-Pten conditional knockout mice (a well-studied genetic model of epilepsy). We used microCT analysis to measure BMD, morphology, and mineralization in NS-Pten^+/+ (wildtype) and NS-Pten^-/- (knockout) mice at 4 and 8weeks, as well as adult Kv4.2^+/+ and Kv4.2^-/- mice. We measured BMD, bone morphology, and mineralization in adult NS-Pten^+/+ mice that received status epilepticus through kainic acid (20mg/kg intraperitoneal). Further, we measured locomotion for NS-Pten^+/+ and NS-Pten^-/- mice at 4 and 6weeks. We found that NS-Pten^-/- mice exhibited low BMD in the tibial metaphysis and midshaft compared to non-epileptic mice. Morphologically, NS-Pten^-/- mice exhibited decreased trabecular volume fraction, and endocortical expansion in both the metaphyeal and diaphyseal compartments. In the midshaft, NS-Pten^-/- mice exhibited reduced tissue mineral density, indicating impaired mineralization in addition to morphological deficits. NS-Pten^-/- mice exhibited hyperactivity in open field testing, suggesting low bone mass in NS-Pten^-/- mice was not attributable to hypoactivity. Differences in BMD were not observed following kainate-induced seizures or in the Kv4.2^-/- model of seizure susceptibility. Our findings suggest that deletion of Pten in the brain results in impaired bone mass and mineralization, which may contribute to weaker bones and thereby a higher fracture risk.

Bone Mineral Changes in Epilepsy Patients During Initial Years of Antiepileptic Drug Therapy

Antiepileptic drug (AED) therapy is associated with decreased bone mineral density; however, the time course for this development is unclear. The aim of this study was to evaluate bone mineral changes during the initial years of AED therapy in AED-naive, newly diagnosed epilepsy patients compared with non-AED users. In 49 epilepsy patients newly started on AEDs and in 53 non-AED users of both genders, bone mineral density (BMD) and bone mineral content were measured using dual-energy X-ray absorptiometry at baseline (within the first year of therapy) and at least 1 yr later. Bone changes between the 2 assessments, adjusted for age, height, and weight, were calculated as the annual rate of change. The median duration of AED therapy was 3.5 mo at baseline and 27.6 mo at follow-up. No overall difference was found in mean BMD and bone mineral content measures between user and nonuser cohorts in both cross-sectional baseline and the annual rate of change (p > 0.05). However, users on carbamazepine monotherapy (n = 11) had an increased annual rate of total hip (-2.1% vs -0.8%, p = 0.020) and femoral neck BMD loss (-2.1% vs -0.6%, p = 0.032) compared to nonusers. They also had a marginally higher rate of femoral neck BMD loss (-2.1%, p = 0.049) compared with valproate (-0.1%, n = 13) and levetiracetam users (+0.6%, n = 13). During the initial years of AED treatment for epilepsy, no difference was found in bone measures between AED users as a group and nonuser cohorts. However, the data suggested that carbamazepine monotherapy was associated with increased bone loss at the hip regions, compared to users of levetiracetam or valproate and nonusers. Larger studies of longer duration are warranted to better delineate the bone effects of specific AEDs, with further consideration of the role of early dual-energy X-ray absorptiometry scanning and careful AED selection in potentially minimizing the impact on bone health in these patients.

Favorable change of lipid profile after carbamazepine withdrawal

OBJECTIVE

Patients treated with carbamazepine (CBZ) have increased serum levels of total cholesterol (TC), high-density lipoproteins (HDL), and low-density lipoproteins (LDL). We aimed to investigate whether these changes of serum lipids are reversible after CBZ withdrawal.

MATERIAL AND METHODS

We used a prospective, randomized double-blinded design. A total of 160 patients who had been seizure free on anti-epileptic drug monotherapy for more than 2 years were included and randomized to withdrawal or not. The intervention was completed by 150 (80 females, 53%) patients. Serum samples from before and 4 months after completed withdrawal or no withdrawal were obtained from 130 patients (63 females, 48%). Of these, 84 were treated with CBZ, 28 with valproate, nine with phenytoin, four with phenobarbital, and five with lamotrigine. Of the patients who had been treated with CBZ, 47 were randomized to the withdrawal group, and 37 were randomized to the non-withdrawal group.

RESULTS

Among the CBZ-treated patients, a significant decrease in serum levels of TC, LDL, and apolipoprotein B (ApoB) were found in the withdrawal group compared with the non-withdrawal group. Mean differences in change were as follows: TC 0.68 mmol/l (P = 0.005, CL - 1.15 to -0.21); LDL - 0.67 mmol/l (P = 0.001, CL - 1.03 to -0.29); ApoB - 0.13 g/l (P = 0.02, CL - 0.23 to -0.03). No significant changes in HDL, apolipoprotein A, and C-reactive protein were detected.

CONCLUSION

Our results indicate that CBZ may have unfavorable effects on serum levels of TC, LDL, and ApoB. However, these changes seem to be reversible even after years of treatment.

The Impact of Anti-Epileptic Drugs on Growth and Bone Metabolism

Epilepsy is a common neurological disorder worldwide and anti-epileptic drugs (AEDs) are always the first choice for treatment. However, more than 50% of patients with epilepsy who take AEDs have reported bone abnormalities. Cytochrome P450 (CYP450) isoenzymes are induced by AEDs, especially the classical AEDs, such as benzodiazepines (BZDs), carbamazepine (CBZ), phenytoin (PT), phenobarbital (PB), and valproic acid (VPA). The induction of CYP450 isoenzymes may cause vitamin D deficiency, hypocalcemia, increased fracture risks, and altered bone turnover, leading to impaired bone mineral density (BMD). Newer AEDs, such as levetiracetam (LEV), oxcarbazepine (OXC), lamotrigine (LTG), topiramate (TPM), gabapentin (GP), and vigabatrin (VB) have broader spectra, and are safer and better tolerated than the classical AEDs. The effects of AEDs on bone health are controversial. This review focuses on the impact of AEDs on growth and bone metabolism and emphasizes the need for caution and timely withdrawal of these medications to avoid serious disabilities.

Monotherapy with Levetiracetam Versus Older AEDs: A Randomized Comparative Trial of Effects on Bone Health

Long-term anti-epileptic drug (AED) therapy is associated with increased fracture risk. This study tested whether substituting the newer AED levetiracetam has less adverse effects on bone than older AEDs. An open-label randomized comparative trial. Participants had "failed" initial monotherapy for partial epilepsy and were randomized to substitution monotherapy with levetiracetam or an older AED (carbamazepine or valproate sodium). Bone health assessments, performed at 3 and 15 months, included areal bone mineral density (aBMD) and content at lumbar spine (LS), total hip (TH), forearm (FA), and femoral neck (FN), radial and tibial peripheral quantitative computed tomography and serum bone turnover markers. Main outcomes were changes by treatment group in aBMD at LS, TH, and FA, radial and tibial trabecular BMD and cortical thickness. 70/84 patients completed assessments (40 in levetiracetam- and 30 in older AED group). Within-group analyses showed decreases in both groups in LS (-9.0 %; p < 0.001 in levetiracetam vs. -9.8 %; p < 0.001 in older AED group), FA (-1.46 %; p < 0.001 vs. -0.96 %; p < 0.001, respectively) and radial trabecular BMD (-1.46 %; p = 0.048 and -2.31 %; p = 0.013, respectively). C-terminal telopeptides of type I collagen (βCTX; bone resorption marker) decreased in both groups (-16.1 %; p = 0.021 vs. -15.2 %; p = 0.028, respectively) whereas procollagen Ι N-terminal peptide (PΙNP; bone formation marker) decreased in older AED group (-27.3 %; p = 0.008). The treatment groups did not differ in any of these measures. In conclusion, use of both levetiracetam and older AEDs was associated with bone loss over 1 year at clinically relevant fracture sites and a reduction in bone turnover.

Calcium and Vitamin D Supplement Prescribing Practices among Providers Caring for Children with Autism Spectrum Disorders: Are We Addressing Bone Health?

Children with autism spectrum disorders (ASD) have several risk factors for low bone mineral density. The gluten-free, casein-free (GFCF) diet is a complementary therapy sometimes used in ASD that raises concerns for the adequacy of calcium and vitamin D intake. This study evaluated the prescribing practices of calcium and vitamin D supplements and the practice of checking 25-hydroxy vitamin D (25(OH)D) levels by providers in 100 children with ASD, 50 of whom were on the GFCF diet. Fifty-two percent and 46% of children on the GFCF diet were on some form of vitamin D and calcium supplements, respectively, compared to 18% and 14% of those not on this diet. Twenty-four percent of children in the GFCF group had a documented 25(OH)D level compared to none in the non-GFCF group. The data highlight a gap in calcium and vitamin D supplement prescribing practices among providers caring for children with ASD as well as a gap in the practice of checking 25(OH)D levels.

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.

Enzyme-inducing antiepileptic drugs and fractures in people with epilepsy: A systematic review

OBJECTIVE

People with epilepsy (PWE) have an increased fracture risk, independent of seizures. Antiepileptic drugs are thought to increase this risk, particularly those that induce the hepatic cytochrome P450 enzyme system. We aimed to determine whether PWE treated with enzyme-inducing antiepileptic drugs (EIAEDs) have decreased bone mineral density (BMD), or increased fracture incidence, versus those treated with non-EIAEDs.

METHODS

We searched MedLine, EMBase, CENTRAL, and CINAHL prior to November 2014 for all studies comparing fracture risk, or BMD change, in PWE treated for ≥ 1 year with EIAEDs versus non-EIAEDs.

RESULTS

Thirteen observational studies met eligibility criteria. These studies, representing 68,973 adult PWE, were significantly heterogeneous, making meta-analysis impossible. Study results were split, with 5 studies showing decreased BMD in EIAED users, 5 studies showing no effect of EIAED on BMD, 2 studies showing increased fracture incidence in EIAED users, and 1 study showing no difference in fracture risk. The largest study (n = 63,259), which was also the most methodologically rigorous, showed an increased hazard ratio of 9-22% for any fracture, and 49-53% for hip fracture, in EIAED users.

SIGNIFICANCE

The literature is divided regarding the bone effects of EIAEDs; however, current best evidence supports an increased fracture risk in PWE treated with an EIAED compared to those treated with non-EIAEDs. A single article dominated our review, and other large methodologically rigorous studies are needed to confirm or refute its results. Further small studies, with limited power to control for multiple potentially confounding variables, are not likely to help.

Bone mineral density in ambulatory children with epilepsy

OBJECTIVE

To elucidate the effects of antiepileptic drugs (AEDs) on bone health status of ambulatory epileptic children.

METHODS

A total of 120 epileptic children aged 2-15 y were enrolled in three groups. The first group was on therapy with carbamazepine, phenobarbital or primidone. The second was treated with valproic acid and the third group was untreated. Serum calcium, phosphorous, total alkaline phosphatase, and parathyroid hormone levels were compared between groups. Bone mineral density tests were also performed at four sites of the lumbar spine and three sites of femoral neck and results were compared between the groups.

RESULTS

Of all enrolled subjects, 67 patients (55.8 %) were vitamin D deficient. The three groups were not significantly different in terms of vitamin D, calcium, phosphorus, total alkaline phosphatase, and parathyroid hormone levels. While patients in first group had lower Z-score of femoral neck and lumbar spine compared to those on valproic acid, these values were also significantly different than that of the third group.

CONCLUSIONS

It can be concluded that both enzyme-inducing AEDs and non enzyme-inducing AEDs decrease bone mineral density (BMD). Also alkaline phosphatase (ALP) is affected in ambulatory epileptic children on enzyme-inducing AEDs. Nevertheless, valproic acid (a non-enzyme-inducing agent) does not have the mentioned side effects.

Interactions between antiepileptic drugs and hormones

Antiepileptic drugs (AEDs) are known to have endocrine side effects in both men and women. These can affect fertility, sexuality, thyroid function, and bone health, all functions of major importance for well-being and quality of life. The liver enzyme inducing antiepileptic drugs (EIAEDs), like phenobarbital, phenytoin, and carbamazepine, and also valproate (VPA), a non-EIAED, are most likely to cause such side effects. AED treatment can alter the levels of different sex hormones. EIAEDs increase sex hormone binding globulin (SHBG) concentrations in both men and women. Over time, this elevation can lead to lower levels of bioactive testosterone and estradiol, which may cause menstrual disturbances, sexual problems, and eventually reduced fertility. VPA can cause weight gain in both men and women. In women, VPA can also lead to androgenization with increased serum testosterone concentrations, menstrual disturbances, and polycystic ovaries. Lamotrigine has not been shown to result in endocrine side effects. The newer AEDs have not yet been thoroughly studied, but case reports indicate that some of these drugs could also be suspected to cause such effects if endocrine changes commence after treatment initiation. It is important to be aware of possible endocrine side effects of AEDs as they can have a major impact on quality of life, and are, at least partly, reversible after AED discontinuation.

Evaluation of current pharmacological treatment options in the management of Rett syndrome: from the present to future therapeutic alternatives

Neurodevelopmental disorders are a large family of conditions of genetic or environmental origin that are characterized by deficiencies in cognitive and behavioral functions. The therapeutic management of individuals with these disorders is typically complex and is limited to the treatment of specific symptoms that characterize each disorder. The neurodevelopmental disorder Rett syndrome (RTT) is the leading cause of severe intellectual disability in females. Mutations in the gene encoding the transcriptional regulator methyl-CpG-binding protein 2 (MECP2), located on the X chromosome, have been confirmed in more than 95% of individuals meeting diagnostic criteria for classical RTT. RTT is characterized by an uneventful early infancy followed by stagnation and regression of growth, motor, language, and social skills later in development. This review will discuss the genetics, pathology, and symptoms that distinguish RTT from other neurodevelopmental disorders associated with intellectual disability. Because great progress has been made in the basic and clinical science of RTT, the goal of this review is to provide a thorough assessment of current pharmacotherapeutic options to treat the symptoms associated with this disorder. Furthermore, we will highlight recent discoveries made with novel pharmacological interventions in experimental preclinical phases, and which have reversed pathological phenotypes in mouse and cell culture models of RTT and may result in clinical trials.

Low vitamin D levels are common in patients with epilepsy

PURPOSE

Vitamin D is important for bone health, and vitamin D deficiency may contribute to other disorders (e.g., autoimmune, infections, cancer, degenerative, diabetic, and vascular). Enzyme-inducing antiepileptic drugs have been particularly implicated for osteoporosis risk given their effects on vitamin D. We examined the prevalence of vitamin D deficiency in adult epilepsy patients.

METHODS

We conducted an observational study of consecutive epilepsy patients treated by two clinicians at the Emory University Epilepsy Center from 2008 to 2011 in order to determine the frequency of low vitamin D levels and possible differential antiepileptic drug risks. Vitamin D 25-OH levels were categorized as low (<20 ng/ml), borderline (20-29 ng/ml), or normal (≥30 ng/ml). Antiepileptic drugs were categorized based on their enzyme inducing properties. Descriptive and inferential statistics were employed.

RESULTS

Vitamin D levels were obtained on 596 patients with epilepsy. Mean age was 41 years (SD=14; range=18-81); 56% were women. Race/ethnicity was 55% Caucasian, 34% Black, 2% Asian, and 7% Unknown. The mean vitamin D level was 22.5 (SD=11.9; range = <4 to 98), and 45% had level <20 ng/ml. Mean vitamin D levels (F=6.48, p=.002) and frequencies of vitamin D categories (p=.002, Chi square test) differed across the antiepileptic drug groups. Vitamin D deficiency was present in 54% of enzyme-inducing and 37% of non-enzyme-inducing antiepileptic drugs groups.

CONCLUSIONS

Vitamin D deficiency is common in patients with epilepsy on antiepileptic drugs. Monitoring of vitamin D should be considered as part of the routine management of patients with epilepsy.

The problem of osteoporosis in epileptic patients taking antiepileptic drugs

INTRODUCTION

Epilepsy is a common neurological disorder associated with recurrent seizures. Therapy with antiepileptic drugs (AEDs) helps achieve seizure remission in approximately 70% of epileptic patients. Treatment with AEDs is frequently lifelong and there are reports suggesting its negative influence on bone health. This is especially important in terms of general occurrence of osteoporosis, affecting over 50 million people worldwide.

AREAS COVERED

This study refers to two main groups of AEDs: hepatic enzyme inducers (carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone and topiramate) and non-inducers (clobazam, clonazepam, ethosuximide, gabapentin, lacosamide, lamotrigine, levetiracetam, pregabalin, tiagabine, valproate, vigabatrin and zonisamide). Some reports indicate that enzyme inducers may exert a more negative influence on bone mineral density (BMD) compared to non-inducers. Bone problems may appear in both sexes during AED therapy, although women are additionally burdened with postmenopausal osteoporosis. Supplementation of vitamin D and calcium in patients on AEDs is recommended.

EXPERT OPINION

Apart from enzyme inducers, valproate (an even enzyme inhibitor) may also negatively affect BMD. However, the untoward effects of AEDs may depend upon their doses and duration of treatment. Although the problem of supplementation of vitamin D and calcium in epileptic patients on AEDs is controversial, there are recommendations to do so.

Epilepsy treatment by sacrificing vitamin D

Epilepsy is one of the most common neurologic disorders in childhood that often requires long term treatment with antiepileptic drugs. Both antiepileptic treatment and the comorbidities associated with epilepsy have a negative impact on bone health in growing children. Given the fact that vitamin D deficiency is a major public health problem worldwide, clinicians caring for children with chronic diseases should be aware of effects of the medication on the bone metabolism. Yet, vitamin D deficiency due to antiepileptic treatment is an overlooked issue among neurologists. In this review, we briefly describe vitamin D metabolism and the effect of vitamin D in the brain. We also discuss the literature in terms of vitamin D deficiency and antiepileptic treatment in the pediatric population.

The impact of the use of antiepileptic drugs on the growth of children

BACKGROUND

This study investigated whether long-term treatment with antiepileptic drugs (AEDs) had negative effects on statural growth and serum calcium levels in children with epilepsy in Taiwan.

METHODS

Children with epilepsy treated with one prescription of AEDs (monotherapy) for at least 1 year were selected. The AEDs included valproic acid (VPA; Deparkin) in 27 children (11 boys and 16 girls) aged 4-18 years, oxcarbazepine (Trileptal) in 30 children (15 boys and 15 girls) aged 5-18 years, topiramate (Topamax) in 19 children (10 boys and 9 girls) aged 6-18 years, and lamotrigine (Lamicta) in eight children (5 boys and 3 girls) aged 5-13 years. Patients with a history of febrile convulsions were selected as the controls.

RESULTS

One year of VPA treatment significantly impaired the statural growth of pediatric patients with epilepsy (p < 0.005) compared with the control group. The underlying mechanism may have been due to the direct effect of VPA on the proliferation of growth plate chondrocytes rather than alterations of serum calcium.

CONCLUSIONS

These results raise serious concerns about the growth of pediatric epilepsy patients who use AEDs, and potentially the need to closely monitor growth in children with epilepsy and adolescents under AED treatment, especially VPA.

Epilepsy and vitamin D

Several disorders, both systemic and those of the nervous system, have been linked with vitamin D deficiency. Neurological disorders with a vitamin D link include but are not limited to multiple sclerosis, Alzheimer and Parkinson disease, as well as cerebrovascular disorders. Epilepsy which is the second leading neurological disorder received much less attention. We review evidence supporting a link between vitamin D and epilepsy including those coming from ecological as well as interventional and animal studies. We also assess the literature on the interaction between antiepileptic drugs and vitamin D. Converging evidence indicates a role for vitamin D deficiency in the pathophysiology of epilepsy.

Antiepileptic drugs and high prevalence of low bone mineral density in a group of inpatients with chronic epilepsy

PURPOSE

Long-term antiepileptic drug use is associated with low bone mineral density (BMD), fractures and abnormalities in bone metabolism. We aimed at determining the prevalence of bone mineral disorders in patients with refractory epilepsy treated with antiepileptic drugs.

METHODS

A cross-sectional survey was conducted in adult patients (n = 205) from a residential unit of a tertiary epilepsy centre. Screening for bone mineral disorders was performed with dual-energy X-ray absorptiometry (DXA) scan of spine and hip (including bone mineral density and vertebral fracture assessment) and laboratory measurements. Patient information regarding demography, epilepsy characteristics and medication use was recorded. Based on DXA T-scores, prevalence of bone mineral disorders (osteopenia and osteoporosis) was calculated. Correlations between DXA T-scores and epilepsy parameters were explored.

RESULTS

Of the 205 patients, there were 10 dropouts. 80% (n = 156/195) of the patients had low BMD: 48.2% had osteopenia and 31.8% had osteoporosis. Of those having low BMD, 51.9% (n = 81/195) was between 18 and 50 years. The T-score of the femoral neck correlated significantly with total duration of epilepsy, cumulative drug load and history of fractures. Linear regression analysis showed that of the epilepsy-related parameters, only cumulative drug load significantly predicted low femoral neck T-score (P = 0.001).

CONCLUSION

In this high-risk population, we obtained a very high prevalence of 80% of low BMD. Both men and women were affected as well as patients <50 years of age. This study illustrates the magnitude of the problem of bone mineral disorders in chronic epilepsy.

Effect of oxcarbazepine on bone mineral density and biochemical markers of bone metabolism in patients with epilepsy

PURPOSE

Antiepileptic drugs (AEDs) may cause adverse effects on bone metabolism and bone mineral density (BMD). The aim of this study is to determine the effect of oxcarbazepine (OXC) monotherapy on biochemical markers of bone metabolism and BMD in epilepsy patients.

METHODS

Forty-one new onset drug naïve epilepsy patients were recruited (19 females, 22 males; mean age: 28.2±8.4 years). We measured biochemical markers of bone metabolism (serum calcium, phosphate, bone alkaline phosphatase, parathyroid hormone, osteocalcin, insulin-like growth factor (IGF)-1, C-telopeptide, Vitamin D3 levels) and BMD by DEXA (dual energy X-ray absorptiometry) method in all patients before and after a long-term OXC monotherapy.

RESULTS

Most of biochemical markers were not changed significantly, but serum calcium (p=0.0087) and bone specific ALP was reduced (p=0.0499) significantly after OXC monotherapy in epilepsy patients. BMD at the lumbar spine (L2 to L4) was significantly increased after OXC monotherapy (p=0.0001), revealed by repeated measures ANOVA with Bonferroni's correction of confounders including sex, age, average dose, and treatment duration. However, BMD at the lumbar spine (L2 to L4) was significantly increased (p=0.012) only in female patients in each gender analysis.

CONCLUSIONS

This study demonstrates that a long-term OXC monotherapy does not appear to have harmful effect on bone health in drug naïve epilepsy patients.

Effects of carbamazepine on serum parathormone, 25- hydroxyvitamin D, bone specific alkaline phosphatase, C-telopeptide, and osteocalcin levels in healthy rats

It is still not completely clear whether carbamazepine causes alterations in vitamin D status and in bone metabolism. The objective of this study was to investigate the effects of carbamazepine on serum levels of 25-hydroxyvitamin D and on biomarkers of bone formation and resorption in healthy rats. Levels of calcium, 25- hydroxyvitamin D, parathormone, C-telopeptide, bone specific alkaline phosphatase and osteocalcin were measured in 3 groups of rats consisting of controls (n=10), isotonic saline solution group (n=10) and carbamazepine group (n=10). Mean calcium levels were found to be significantly lower in healthy controls in comparison to isotonic saline solution and carbamazepine groups (10.0±0.24, 10.81±0.16, 10.93±0.22 mg/dL, respectively, p<0.05). Mean levels of 25- hydroxyvitamin D, were found to be significantly higher in control group compared to isotonic saline solution group (25- hydroxyvitamin D; 25.91±1.12, 19.99±0.99 ng/mL, respectively, p<0.01). Mean levels of parathormone and osteocalcin were found to be significantly higher in control group compared to isotonic saline solution group and carbamazepine group. Parathormone levels were measured as 3.46±0.83, 1.08±0.08, 0.94±0.02 pg/mL, respectively (p<0.01). Osteocalcine levels were measured as 1.66±0.001, 1.32±0.002, 1.32±0.001 ng/mL, respectively (p<0.001). A significant difference in terms of mean serum bone specific alkaline phosphatase and C-telopeptide levels among groups was not observed. The main outcome of this prospective study in healthy rats showed no change in biochemical parameters of bone turnover during treatment with carbamazepine.

Pregnancy, epilepsy, and women's issues

PURPOSE OF REVIEW

Optimal treatment of women with epilepsy includes consideration of the complex interactions of sex steroid hormones with epilepsy and antiepileptic drugs, and of the potential risks of any antiepileptic drug prescribed during a pregnancy.

RECENT FINDINGS

Clinical studies in women with epilepsy have provided a better foundation of knowledge about the complex relationships between cycling sex steroid hormones, seizure frequency, antiepileptic drugs, contraception, and neuroendocrine abnormalities. Pregnancy registries and observational studies have provided key data that allow for a better estimation of risks to the developing fetus.

SUMMARY

Understanding these key factors should enable informed treatment recommendations that can reduce adverse health effects in women with epilepsy and improve both seizure control and maternal and fetal outcomes.

The long-term safety of antiepileptic drugs

Antiepileptic drugs (AEDs) are used by millions of people worldwide for the treatment of epilepsy, as well as in many other neurological and psychiatric conditions. They are frequently associated with adverse effects (AEs), which have an impact on the tolerability and success of treatment. Half the people who develop intolerable AEs discontinue treatment early on after initiation, while the majority of people will continue to be exposed to their effects for long periods of time. The long-term safety of AEDs reflects their potential for chronic, cumulative dose effects; rare, but potentially serious late idiosyncratic effects; late, dose-related effects; and delayed, teratogenic or neurodevelopmental effects. These AEs can affect every body system and are usually insidious. With the exception of delayed effects, most other late or chronic AEs are reversible. To date, there is no clear evidence of a carcinogenic effect of AEDs in humans. While physicians are aware of the long-term AEs of old AEDs (the traditional liver enzyme-inducing AEDs and valproate), information about AEs of new AEDs (such as lamotrigine, levetiracetam, oxcarbazepine, topiramate or zonisamide), particularly of their teratogenic effects, has emerged over the years. Sporadic publications have raised issues about AEs of the newer AEDs eslicarbazepine, retigabine, rufinamide, lacosamide and perampanel but their long-term safety profiles may take years to be fully appreciated. Physicians should not only be aware of the late and chronic AEs of AEDs but should systematically enquire and screen for these according to the individual AED AE profile. Care should be taken for individuals with comorbid conditions that may render them more susceptible to specific AEs. Prevention and appropriate management of long-term AED AEs is expected to improve adherence to treatment, quality of life and control of epilepsy.

Bone turnover markers in epileptic patients under chronic valproate therapy

BACKGROUND

The effects of chronic valproic acid administration on bone health have been a matter of concern and controversy. In this study, the bone status following valproate intake was assessed by using several bone-related biochemical markers.

MATERIALS AND METHODS

In this case-control study, 62 epileptic patients and 40 age- and gender-matched controls were enrolled. The patients had been under chronic valproate therapy (758 ± 29 mg/day) for at least the past 6 months, without any vitamin D/or calcium supplementation. Serum markers of bone turnover (carboxy-terminal telopeptide of type I collagen (CTX) and bone-specific alkaline phosphatase [BALP]), calcium, phosphorus, total alkaline phosphatase, and parathyroid hormone levels were measured in both groups.

RESULTS

The markers of bone turnover as well as other measured bone biochemical parameters did not statistically differ between the two groups.

CONCLUSION

Valproate therapy at the mentioned doses does not seem to change bone turnover in adult epileptic patients.