Effects of anticonvulsant therapy on vitamin D status in children: prospective monitoring study

Standard and high dose ergocalciferol regimens for treatment of hypovitaminosis D in epileptic children and adolescents

OBJECTIVES

Children with epilepsy are at increased risk of vitamin D deficiency. We aimed to compare the effect of two ergocalciferol regimens given for 90 days.

METHODS

Epileptic patients aged 5-18 years who received at least one antiepileptic drug (AED) for more than 6 months and had serum 25-OHD <30 ng/mL were randomized to receive 20,000 IU/10 d (standard dose, n=41) or 60,000 IU/10 d (high dose, n=41) of oral ergocalciferol. Serum Ca, P, Mg, ALP, iPTH and urine Ca/Cr ratio were measured at baseline and after 90 days of treatment. Change in serum 25-OHD and vitamin D status after treatment was evaluated.

RESULTS

The initial serum 25-OHD in the standard dose and high dose group was 19.5 ± 4.9 and 18.4 ± 4.6 ng/mL, respectively. Serum 25-OHD after treatment was significantly higher in the high dose group (39.0 ± 11.5 vs. 27.5 ± 8.6 ng/mL, p<0.05). The average increase in serum 25-OHD in the high dose and standard dose group was 20.6 ± 11.4 and 7.2 ± 7.5 ng/mL, respectively (p<0.05). Normalized serum 25-OHD was achieved in 80.5% of the high dose group compared to 36.6% of the standard dose group (p<0.05). No adverse events were found. Patients with a BMI Z-score>0 had a 2.5 times greater risk of continued hypovitaminosis D after treatment compared to those with a BMI Z-score<0 (95% CI: 1.0-5.9, p<0.05).

CONCLUSIONS

Oral ergocalciferol 60,000 IU/10 d for 90 days was more effective at normalizing serum 25-OHD than 20,000 IU/10 d in epileptic children and adolescents who were receiving AEDs.

Sex differences in side effects of antiseizure medications in pediatric patients with epilepsy: A systematic review

PURPOSE

To perform a systematic review searching for differences in the side effects of antiseizure medications (ASMs) with respect to sex in pediatric patients with epilepsy.

METHODS

We carried out a comprehensive literature search of the PubMed database and all results up to April 2020 were included. Titles, abstracts, and full texts of the articles were screened by two independent reviewers. We included all studies evaluating the side effects of ASMs in patients with epilepsy younger than 18 years, with reference to the two sexes. Studies on ASMs used for indications other than epilepsy were excluded.

RESULTS

A total of 5164 studies were identified. Sixty-seven studies were finally included, 5 of them also including adult patients in the sample. Sixteen studies revealed sex-related differences in side effects of ASMs, disclosing a higher frequency of general side effects in girls: a higher risk of overweight, hyperammonaemia, high leptin levels, and carnitine deficiency in girls on valproic acid; a lower height increase, an increased risk of weight loss, the anecdotical occurrence of acute psychosis in girls on topiramate; a higher risk of retinal toxicity in boys on vigabatrin.

CONCLUSION

The effect of sex on susceptibility to side effects of ASMs is poorly investigated with sparse results, and it could be underestimated. The findings of our study point to the presence of sex differences which should be thoroughly investigated to be confirmed, highlighting the need for a systematic evaluation of sex as a determinant variable influencing the response to medications in clinical research.

Association between serum vitamin D levels and age in patients with epilepsy: a retrospective study from an epilepsy center in Saudi Arabia

BACKGROUND

Vitamin D deficiency has been linked to various medical conditions such as bone loss, decreased mineralization, endocrine disorders, and central nervous system disorders, including epilepsy. Vitamin D deficiency is prevalent among patients with epilepsy (PWE). However, the specific association between vitamin D levels and age in PWE is unclear.

OBJECTIVES

Identify the relation between vitamin D level and age in PWE and evaluate factors that may play a role in seizure control.

DESIGN

Retrospective analytical medical record review SETTING: Outpatient epilepsy research clinic in Saudi Arabia PATIENTS AND METHODS: Between November 2016 and April 2020, we selected eligible PWE aged older than 14 years whose vita-min D levels were recorded at least once after reviewing 1550 patient electronic files. We analyzed data on serum vitamin D level by age and other factors, vitamin D supplement use, seizure classification, and conducted a multivariate logistic regression to assess associations with seizure control.

MAIN OUTCOME MEASURES

Relationships between vitamin D levels and age and factors that might affect seizure control.

SAMPLE SIZE

524 patients RESULTS: The prevalence of low serum vitamin D levels was high (86.8%). The median vitamin D level in all patients was low (38 nmol/L), and was lower in young PWE than in adult PWE (P<.01). Only 146 patients received vitamin D supplements. High vitamin D levels were associated with a 40% seizure reduction.

CONCLUSION

Vitamin D deficiency is underestimated in PWE in Saudi Arabia, and is more prevalent among young adults and patients on polytherapy than in other PWE. Patients with high vitamin D levels had good seizure control compared with those with low levels. The effect of vitamin D supplements on seizure control should be further investigated in randomized control trials.

LIMITATIONS

Retrospective study and no categorization by presence of supplementation.

CONFLICT OF INTEREST

None.

The Multiple Effects of Vitamin D against Chronic Diseases: From Reduction of Lipid Peroxidation to Updated Evidence from Clinical Studies

Background: Vitamin D exerts multiple beneficial effects in humans, including neuronal, immune, and bone homeostasis and the regulation of cardiovascular functions. Recent studies correlate vitamin D with cancer cell growth and survival, but meta-analyses on this topic are often not consistent. Methods: A systematic search of the PubMed database and the Clinical Trial Register was performed to identify all potentially relevant English-language scientific papers containing original research articles on the effects of vitamin D on human health. Results: In this review, we analyzed the antioxidant and anti-inflammatory effects of vitamin D against acute and chronic diseases, focusing particularly on cancer, immune-related diseases, cardiomyophaties (including heart failure, cardiac arrhythmias, and atherosclerosis) and infectious diseases. Conclusions: Vitamin D significantly reduces the pro-oxidant systemic and tissue biomarkers involved in the development, progression, and recurrence of chronic cardiometabolic disease and cancer. The overall picture of this review provides the basis for new randomized controlled trials of oral vitamin D supplementation in patients with cancer and infectious, neurodegenerative, and cardiovascular diseases aimed at reducing risk factors for disease recurrence and improving quality of life.

Valproate-associated hair abnormalities: Pathophysiology and management strategies

OBJECTIVE

To review the literature on valproate-associated hair abnormalities and the available treatment options.

METHODS

We searched PubMed and Google Scholar with keywords including "valproate", "valproic acid", "hair", "alopecia", and "effluvium," supplemented with hand search from cross-references. We included all types of studies including case reports in this review.

RESULTS

The pathophysiology of hair loss includes telogen effluvium, biotin, mineral deficiency, and possibly hyperandrogenism. Diagnosis is based on history of hair loss or abnormalities following valproate treatment, and is confirmed by use of simple clinical tests such as pull test and modified wash test. Treatment involves reassurance and advice on hair care, and if possible drug discontinuation or dose reduction. Medications such as biotin and other vitamins with minerals supplementation is effective for most individuals with hair loss. Other treatment options are agomelatine, topical valproate or minoxidil, though these lack evidence.

CONCLUSION

Hair abnormalities with valproate are common, benign adverse effects, and management includes general measures and specific treatment options.

A vitamin D enriched diet attenuates sex-specific behavioral deficits, increases the lifespan, but does not rescue bone abnormalities in a mouse model of cortical dysplasia

Individuals who experience recurrent spontaneous seizures often show behavioral and physiological comorbidities. Those with epilepsy are at a high risk of bone fractures (independent of seizure-related falls) and show a higher rate of a diagnosis of Autism Spectrum Disorder. The neural subset-specific (NS) Pten knockout (KO) mouse has an epilepsy phenotype, has been characterized to show autistic-like deficits, and has an osteoporosis phenotype. The current study examined the effect of a vitamin D enriched diet (20,000 IU VD) in the NS-Pten KO and wildtype mice. Mice were placed onto a vitamin D enriched diet at 4 weeks of age and maintained on that diet throughout testing. Behavioral testing began at 6 weeks of age and included tests for general activity, anxiety, repetitive behaviors, social behaviors, and memory. Results indicated that a vitamin D diet attenuated hypoactivity levels in male KO mice (p < 0.05). In a social partition task, vitamin D increased sociability in male wildtype mice, (p < 0.05). Most significantly, vitamin D fortified diet increased percent survival in KO animals and decreased the level of microglia marker IBA-1 and mTOR (mammalian target of rapamycin) downstream targets pS6 and pAKT. A high vitamin D diet did not reverse bone deficits in male or female KO mice. Overall, these findings suggest that a vitamin D enriched diet had a significant impact on the behavioral phenotype of NS-Pten KO mice, suggesting that dietary manipulations could be a potential therapeutic option for autistic-like behavior.

Vitamin D deficiency in pediatric patients using antiepileptic drugs: systematic review with meta-analysis

OBJECTIVES

To measure the prevalence of vitamin D deficiency (through the 25-hydroxyvitamin D metabolite) in pediatric patients using antiepileptic drugs.

SOURCE OF DATA

Meta-analysis of studies identified through search in the PubMed, Embase, LILACS, and Cochrane Library databases, on February 19, 2019.

SUMMARY OF DATA

A total of 748 articles were identified, 29 of which were relevant to the objectives of this study. The prevalence of vitamin D deficiency found was 0.32 (95% CI=0.25-0.41; I²=92%, p<0.01). In the subgroup analyses, the most significant results were observed in the group of patients using cytochrome P450-inducing antiepileptic drugs, with a prevalence of 0.33 (95% CI=0.21-0.47; I²=86%, p<0.01) and, considering the study design, in the subgroup of cohort studies, with a prevalence of 0.52 (95% CI=0.40-0.64; I²=76%, p<0.01).

CONCLUSIONS

Taking into account the deleterious effects of vitamin D deficiency on the bone health of individuals using antiepileptic drugs, it is suggested to include in their care 25-hydroxyvitamin D monitoring, cholecalciferol supplementation, and treatment of the deficiency, when present.

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.

Prevalence and Risk Factors of Hypovitaminosis-D in Children with Cognitive and Movement Disorders

OBJECTIVES

To document the prevalence of hypovitaminosis-D in children with intellectual and movement disorders and to identify the risk factors in vitamin D deficient children.

METHODS

This is a cross-sectional study on 90 children with neurodevelopmental disabilities. The prevalence of hypovitaminosis-D and the risk factors such as sun exposure, age-appropriate mobility, diet, skin color and anti-epileptic medications were examined in children with cognitive disorders and movement disorders.

RESULTS

The mean serum vitamin D level in children with cognitive disability (n = 46) was found to be 26.7 ± 16.3 ng/L and in the children with movement disability (n = 44) it was 27.9 ± 10.5 ng/L. Though the risk factors were found in greater numbers in children in the deficient group (vitamin D < 30 ng/L), the difference between the two groups was not significant. Of the 90 children, 86 (95.5%) had at least one sign of vitamin D deficiency. Lowest levels of vitamin D were seen in autistic spectrum disorder and learning disabilities in the Cognitive Disability group and hemiplegia in the Movement Disability group.

CONCLUSIONS

The prevalence of vitamin D deficiency in children with neurodevelopmental disabilities was 72.2%, with 76.1% in the cognitive disability group and 68.2% in the movement disability group. The risk factors were more common in vitamin D deficient children.

Vitamin D supplementation and bone markers in ambulatory children on long-term valproic acid therapy. A prospective interventional study

PURPOSE

Our aim was to investigate any adverse effects of long-term valproic acid (VPA) therapy on bone biochemical markers in ambulatory children and adolescents with epilepsy, and the possible benefits of vitamin D supplementation on the same markers.

METHODS

In this single center, the prospective interventional study levels of 25-hydroxyvitamin D (25OHD) and the bone turnover indices of Crosslaps (CTX), total alkaline phosphatase (tALP), osteoprotegerin (OPG), and the receptor activator for nuclear factor kB (RANK) ligand (sRANKL) were assessed before and after one year of vitamin D intake (400 IU/d) and were compared with those of clinically healthy controls. Fifty-four ambulatory children with mean (±standard deviation [SD]) age 9.0 ± 4.5 yrs on VPA (200-1200 mg/d) long-term monotherapy (mean: 3.2 ± 2.6 yrs) were studied, before and after a year's vitamin D intake (400 IU/d).

RESULTS

Nearly half of the cases were vitamin D insufficient/deficient with mean levels 23.1 ± 12.8 vs 31.8 ± 16.2 ng/mL of controls (p = 0.004) and after the year of vitamin D intake increased to 43.2 ± 21.7 ng/mL (p < 0.0001). In parallel, serum CTX and tALP had a decreasing trend approaching control levels but OPG and sRANKL did not change and were not different from controls. However, after vitamin D intake, a positive correlation was seen between 25OHD and OPG but not before.

CONCLUSIONS

The findings imply a higher bone turnover in the young patients on long-term VPA therapy that decreased after vitamin D intake.

Valproate decreases vitamin D levels in pediatric patients with epilepsy

PURPOSE

To compare Vitamin D (Vit D) levels in children with epilepsy on valproate monotherapy with healthy controls.

METHODS

A meta-analysis performed on articles identified from PubMed and Web of Science online databases evaluated using National Institute of Health National Heart, Lung, and Blood Institute Study Quality Assessment Tools. Subgroup analyses and publication bias assessments were also performed.

RESULTS

Eleven publications were eligible based on inclusion/exclusion criteria for the meta-analysis. Results noted a decrease in the mean Vit D level in children with epilepsy on valproate monotherapy compared with healthy children with a Standard Mean Difference = -0.313 [-0.457, -0.169]. Cumulative meta-analysis showed progressive negative effect of valproate therapy on Vit D levels across time. Other antiepileptic medications caused a similar effect on Vit D status. There was no evidence of publication bias in the analyses. Type of study design and country of origin introduced heterogeneities into the meta-analyses.

CONCLUSION

This meta-analysis provides evidence that long-term therapy with valproate causes a decrease in Vit D levels in children. Therefore, in children with a seizure disorder on long-term valproate therapy, 25-OH-Vit D levels should be monitored and appropriate supplementation implemented if levels are deficient.

A case series of benign transient hyperphosphatasemia from a pediatric endocrinology reference health facility in Turkey

Introduction

Benign transient hyperphosphatasemia (BTH), even a known condition, is not very well managed by primary care physicians. The diagnostic criteria for BTH were alkaline phosphatase (ALP) levels above 3-5 times greater than the age adjusted upper limit of normal among children under 5 years with no evidence of liver or bone disease whose ALP values resolved within 4 months.

Methods

This study involved 15 patients aged 0-5 years, who were referred to the pediatric endocrinology clinic for elevated ALP levels. They were diagnosed with BTH. We examined demographic and biochemical parameters including ALP and ALP isoenzymes, liver enzymes, calcium, phosphate, and parathormone (PTH) levels to rule out liver or bone disease as a cause for hyperphosphatasaemia.

Results

Of 15 patients 7 were male and 8 were female. Mean age was 2.45 ± 1.09 (range 1.2-4.6) years. Mean serum ALP level was 2315 ± 1028 IU/L (1102-4662), while liver enzymes, calcium, phosphate, PTH and vitamin D3 levels were in normal ranges. The mean normalization period of ALP was 2.4 ± 1.1 (0.5-4) months, and all were normal at the end of 4 months without any treatment.

Conclusion

This study and literature knowledge related to BTH has shown that being aware of BTH is very important for a primary care physician. Paediatricians can conveniently manage the differential diagnosis and follow up this period of elevated ALP.

Vitamin D supplementation to prevent vitamin D deficiency for children with epilepsy: Randomized pragmatic trial protocol

BACKGROUND

Vitamin D deficiency is highly prevalent among children with epilepsy. Lack of high-quality evidence led to variability among scientific societies recommendations. Therefore, we aim to determine the efficacy of different common doses used in the pediatric practice to maintain optimal 25-hydroxy vitamin D (25 [OH] vitamin D) level in children with epilepsy and normal baseline 25 (OH) vitamin D level over 6 months of supplementation.

METHODS

This is a protocol for phase IV pragmatic randomized superiority controlled open-label trial at King Saud University Medical City in Riyadh. Children with epilepsy and receiving chronic antiepliptic medication and normal baseline 25 (OH) vitamin D level will be randomly assigned to receive Cholecalciferol 400 IU/day versus 1000 IU/day for 6 months. Our primary outcome is the proportion of children with vitamin D insufficiency (25 (OH) vitamin D level < 75nmol/L) at 6 months. Secondary outcomes include seizure treatment failure, seizure frequency, parathyroid hormone (PTH) levels, bone mineral density, and safety.

DISCUSSION

Our trial is set out to evaluate the efficacy of common different vitamin D maintenance doses on 25 (OH) vitamin D level, seizure control, and bone health for children with epilepsy. The results of our study will possibly help in shaping current vitamin D guidelines for vitamin D supplementation in children with epilepsy and provide a link between 25 (OH) vitamin D level and seizure control.

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.

A mechanism based approach to management of children with end-stage liver disease

Due to parallel advances in surgical and acute care disciplines, liver transplantation (LT) has revolutionized the outlook for children with end-stage liver disease (ESLD). Contrary to advances in technical aspects of LT and the peri-operative care, pre-transplant management of ESLD remains quite a formidable challenge. Areas covered: This review provides mechanisms based management strategies to address common complications of ESLD including malnutrition, amended metabolic pathways, gastrointestinal dysfunction, and development of ascites. Clinically relevant discussion of each paradigm is followed by an account of high impact therapeutic interventions which can be used as guides for formulating management plans. A tabulated summary of the suggested interventions is also provided. Indeed, execution of a dynamic plan tailored to the evolution of pathophysiologic derangements can further enhance outcomes of pediatric LT. Expert commentary: LT has evolved as a dependable therapeutic option for a variety of fatal pediatric liver diseases. However, relative organ shortage remains a formidable challenge. Similarly, consumer expectations continue to grow for sustained improvement of graft and patient survival after LT. In this environment, the level of sophistication applied to the management ESLD before LT stands out as a major opportunity with lasting impact on the future of pediatric LT.

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.

Vitamin D Deficiency in Children With Newly Diagnosed Idiopathic Epilepsy

Several studies have shown a link between vitamin D deficiency and epilepsy. This study includes 60 newly diagnosed idiopathic epilepsy patients and 101 healthy controls (between the ages of 5 and 16). Each group was also divided into two subgroups according to seasonal changes in terms of months of longer versus shorter daylight. We retrospectively evaluated the levels of calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and 25-OH vitamin-D3 in the study participants. Levels below 20 ng/ml were defined as vitamin D deficiency and levels of 20-30 ng/ml as insufficiency. There were no significant differences in age, gender distribution and levels of calcium, phosphorus, alkaline phosphatase and parathyroid hormone between the groups. The level of 25-OH vitamin-D3 in the patient group was significantly lower when compared to the control group (p < 0.05) (14.07 ± 8.12 and 23.38 ± 12.80 ng/ml, respectively). This difference also held true when evaluation was made according to seasonal evaluation (12.38 ± 6.53 and 17.64 ± 1.14 in shorter daylight and 18.71 ± 9.87 and 30.82 ± 1.04 in longer daylight).

Effects of antiepileptic drugs on bone mineral density and bone metabolism in children: a meta-analysis

OBJECTIVE

The aim of our meta-analysis was to assess the effects of antiepileptic drugs on bone mineral density and bone metabolism in epileptic children.

METHODS

Searches of PubMed and Web of Science were undertaken to identify studies evaluating the association between antiepileptic drugs and bone mineral density and bone metabolism.

RESULTS

A total of 22 studies with 1492 subjects were included in our research. We identified: (1) a reduction in bone mineral density at lumbar spine (standardized mean difference (SMD)=-0.30, 95% confidence interval (CI) [-0.61, -0.05]), trochanter (mean difference (MD)=-0.07, 95% CI [-0.10, -0.05]), femoral neck (MD=-0.05, 95% CI [-0.09, -0.02]), and total body bone mineral density (MD=-0.33, 95% CI [-0.51, -0.15]); (2) a reduction in 25-hydroxyvitamin D (MD=-3.37, 95% CI [-5.94, -0.80]) and an increase in serum alkaline phosphatase (SMD=0.71, 95% CI [0.38, 1.05]); (3) no significant changes in serum parathyroid hormone, calcium, or phosphorus.

CONCLUSIONS

Our meta-analysis suggests that treatment with antiepileptic drugs may be associated with decreased bone mineral density in epileptic children.

Longitudinal change of vitamin D status in children with epilepsy on antiepileptic drugs: prevalence and risk factors

BACKGROUND

Our aim was to evaluate the prevalence and risk factors of vitamin D deficiency and the changes of vitamin D level among children with epilepsy on antiepileptic drugs.

METHODS

The levels of serum 25-hydroxy vitamin D were measured at the start of antiepileptic drugs and at 6- to 12-month intervals in children with epilepsy taking antiepileptic drugs in Pusan National University Children's Hospital. Vitamin D deficiency was defined as 25-hydroxy vitamin D levels <20 ng/mL and insufficiency between 21 and 29 ng/mL.

RESULTS

A total of 143 children (103 boys and 40 girls) with the mean age of 7.4 ± 5.4 years were included. The mean follow-up duration was 1.8 ± 0.8 years. At the start of antiepileptic drugs and the last follow-up, vitamin D deficiency or insufficiency was recognized in 56.6% (81 of 143) and 79.0% (113 of 143), respectively (P < 0.01). The mean value of initial 25-hydroxy vitamin D was 31.1 ± 14.7 ng/mL, which was significantly decreased to 20.2 ± 14.9 ng/mL (P < 0.01) in the last follow-up. Polytherapy (-16.0 ± 13.6 ng/mL), longer duration of ≥2 years (-23.5 ± 9.1 ng/mL), tube feeding (-18.2 ± 14.5 ng/mL), and overweight with body mass index of eighty-fifth percentile or greater (-17.0 ± 12.1 ng/mL) had a significant negative effect for the longitudinal change of 25-hydroxy vitamin D. Age, etiologies, seizure outcomes, and type of antiepileptic drugs (enzyme-inducing versus nonenzyme-inducing antiepileptic drugs) did not affect the longitudinal decrease of 25-hydroxy vitamin D.

CONCLUSIONS

A high proportion of these children on antiepileptic drugs had hypovitaminosis D and a significant decrease between the initial and the last follow-up. Polytherapy and longer duration of antiepileptic drugs, tube feeding, and overweight were independently associated with longitudinally significant decrease of 25-hydroxy vitamin D.

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.

Vitamin D deficiency among children with epilepsy in South Queensland

This study evaluated prevalence and risk factors for vitamin D deficiency among children with epilepsy on long-term antiepileptic drugs treated in South Queensland, Australia. Children with epilepsy seen in a tertiary neurology clinic were contacted requesting bone health blood tests during winter of 2011. Vitamin D deficiency was defined as 25-hydroxy vitamin D levels <20 ng/mL, and insufficiency between 21 and 29 ng/mL. One hundred thirty letters were sent, with 111 (85%) subsequently having blood tests performed. Vitamin D deficiency was identified in 24 (22%) of 111 and an additional 45 (41%) of 111 had vitamin D insufficiency. Multiple logistic regression analysis identified children on >2 antiepileptic drugs or with underlying genetic etiologies were more likely to have vitamin D deficiency. High proportion of children on long-term antiepileptic drugs in Queensland risk vitamin D deficiency and insufficiency despite living in the subtropics. Vitamin D monitoring and supplementation is important in the management of children on long-term antiepileptic drugs requiring tertiary care in Queensland.

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 bone metabolism in children: data from 128 patients

There are conflicting results concerning bone metabolism in children receiving antiepileptic medication, with data concentrating on neurologically impaired patients. We performed a multicenter cross-sectional study in otherwise healthy children who received monotherapy with valproic acid, oxcarbazepine, lamotrigine, sulthiame, levetiracetam, or topiramate for at least 6 months. Data on calcium, phosphorus, alkaline phosphatase, 25-OH vitamin D, and parathormone were collected. Among 128 patients, 24.4% had hypocalcemia, 25.4% hypophosphatemia, and 13.3% (n = 17) 25-OH vitamin D levels <10 ng/mL. All patients were clinically asymptomatic. Mean calcium concentrations were found to be significantly lower among the study population (2.41 mmol/L) compared with healthy controls (2.53 mmol/L). Lowest mean concentration was observed in patients treated with sulthiame followed by oxcarbazepine and valproic acid. No influence of calcium intake or therapy on bone metabolism was noted. Effects on bone metabolism of anticonvulsive monotherapy are not restricted to neurologically impaired children but also affect otherwise healthy children.

Drug-vitamin D interactions: a systematic review of the literature

Extensive media coverage of the potential health benefits of vitamin D supplementation has translated into substantial increases in supplement sales over recent years. Yet, the potential for drug-vitamin D interactions is rarely considered. This systematic review of the literature was conducted to evaluate the extent to which drugs affect vitamin D status or supplementation alters drug effectiveness or toxicity in humans. Electronic databases were used to identify eligible peer-reviewed studies published through September 1, 2010. Study characteristics and findings were abstracted, and quality was assessed for each study. A total of 109 unique reports met the inclusion criteria. The majority of eligible studies were classified as class C (nonrandomized trials, case-control studies, or time series) or D (cross-sectional, trend, case report/series, or before-and-after studies). Only 2 class C and 3 class D studies were of positive quality. Insufficient evidence was available to determine whether lipase inhibitors, antimicrobial agents, antiepileptic drugs, highly active antiretroviral agents, or H2 receptor antagonists alter serum 25(OH)D concentrations. Atorvastatin appears to increase 25(OH)D concentrations, whereas concurrent vitamin D supplementation decreases concentrations of atorvastatin. Use of thiazide diuretics in combination with calcium and vitamin D supplements may cause hypercalcemia in the elderly or those with compromised renal function or hyperparathyroidism. Larger studies with stronger study designs are needed to clarify potential drug-vitamin D interactions, especially for drugs metabolized by cytochrome P450 3A4 (CYP3A4). Healthcare providers should be aware of the potential for drug-vitamin D interactions.

Vitamin D deficiency in children with epilepsy: Do we need to detect and treat it?

Children and adolescents treated with antiepileptic drugs are known to have problems with bone metabolism, bone mineral density loss, and 2-3 times the fracture risk of healthy controls. We reviewed the literature regarding bone mineral density in children with epilepsy and vitamin D therapy in children treated with anti-epileptic drugs. Studies of bone mineral density markers in children with epilepsy have mostly found little significant difference in bone mineral density markers in children with epilepsy. They have been limited by small sample size and many of the studies have not corrected for confounding factors such as comorbidities, mobility, nutrition, and obesity. Studies of vitamin D therapy in children with epilepsy have shown little evidence of effect and have been similarly limited by lack of stratification with regard to confounding factors. There is a need for larger studies, using clinically significant outcomes such as fractures, including at risk populations such as symptomatic generalised epilepsy, impaired mobility, and polytherapy. At the present time in the absence of good evidence to the contrary, there remains concern that children with epilepsy are at risk of poor bone health and that vitamin D therapy may be beneficial. As low-dose vitamin D supplementation (400 IU per day) is now recommended for healthy children and it is biologically feasible that children with epilepsy may be at higher risk of clinically significant deficiency, it is important that neurologists ensure that low-dose vitamin D supplementation should be prescribed and compliance followed up in children with epilepsy.

Elevated Alkaline Phosphatase in Children: An Algorithm to Determine When a "Wait and See" Approach is Optimal

Due to the possibility of underlying hepatobiliaryor bone diseases, the diagnostic work up of a child with elevated alkaline phosphatase (AP) levels can be quite costly. In a significant proportion of these patients, elevated AP is benign, requiring no intervention: hence, known as transient hyperphosphatasemia (THP) of infants and children. A 27-month old previously healthy Caucasian female was found to have isolated elevation of AP four weeks after the initial symptoms of acute gastroenteritis. One month later, when seen in hepatobiliary clinic, signs and symptoms of gastrointestinal, hepatobiliary, or bone disease were absent and physical examination was normal. The diagnosis of THP was made, and, as anticipated, AP levels normalized after four months. Using this case as an example, we suggest an algorithm that can be utilized as a guide in a primary care setting to arrive at the diagnosis of THP and avoid further tests or referrals.

Role of nutrition in pediatric chronic liver disease

The liver plays a central role in energy and nutrient metabolism. Malnutrition is highly prevalent among patients with chronic liver disease and leads to increased morbidity and mortality rates. This review addresses the causes of malnutrition, methods used to assess nutrition status, and appropriate treatment strategies in pediatric patients with chronic liver disease.

Effect of carbamazepine therapy on vitamin D and parathormone in epileptic children

Evidence suggests that carbamazepine affects bone metabolism by altering vitamin D status. We prospectively compared 25-hydroxyvitamin D, parathormone, calcium, phosphorus, and alkaline phosphatase levels at initiation and 6 months of carbamazepine therapy in children, and correlated them with carbamazepine levels. We included 47 children newly diagnosed with partial epilepsy, initiated on carbamazepine therapy. Of these, 32 were studied for 6 months. Children were managed according to standard protocol. Various parameters were measured at initiation and at 6 months. Carbamazepine levels were estimated after 6 months. Mean age was 6.72 ± 2.22 years S.D. Mean 25-hydroxyvitamin D was 14.45 ± 9.77 ng/mL S.D. and 11.31 ± 9.15 ng/mL S.D. at baseline and 6 months (P = 0.023), respectively (21.7% decline). Mean parathormone increased from 34.24 ± 21.38 pg/mL S.D. to 45.01 ± 24.46 pg/mL S.D. (P = 0.001). Change in vitamin D correlated negatively with change in parathormone (r = -0.404, P = 0.022). Serum alkaline phosphatase increased from 283.50 ± 100.10 IU/L S.D. to 364.25 ± 126.98 IU/L S.D. (P < 0.001). Changes in vitamin D and parathormone did not correlate significantly with carbamazepine level. Carbamazepine therapy decreased levels of vitamin D. Hence vitamin D monitoring and supplementation may help prevent alterations in bone metabolism.

Prevalence and risk factors for vitamin D insufficiency among children with epilepsy

This cross-sectional study was designed to determine the prevalence of, and risk factors for, vitamin D insufficiency among children treated for epilepsy in a general pediatric neurology clinic. Included were 78 children with epilepsy, aged 3-17 years, treated by the authors between September 2008 and March 2009. Vitamin D levels and relevant risk factors were evaluated using multiple logistic regression. Of the 78 children, 41% were male and 81% were of European origin; the mean age was 11.64 + or - 4.37 years. 25-hydroxyvitamin D levels of <20 ng/mL were observed in 25% of the children and levels considered to be normal (>32 ng/mL) were observed in only 25%. Girls and children with elevated body mass index were at increased risk for low 25-hydroxyvitamin D. The odds ratio for low 25-hydroxyvitamin D was 4.07 for girls versus boys, with a 95% confidence interval of 1.18-13.97; for each 1-unit increase in body mass index, the odds ratio was 1.179, with a 95% confidence interval of 1.047-1.329. Use of newer antiepileptic drugs was not associated with altered risk, compared with older enzyme-inducing drugs. Vitamin D insufficiency was highly prevalent in this unselected population of children with epilepsy. Female sex and increased body mass index were significant risk factors for low vitamin D levels, but antiepileptic drug regimen was not.

Vitamin D and bone health among children with epilepsy

The lay media and scientific literature have focused increasing attention on vitamin D deficiency and insufficiency in recent years. Low vitamin D levels confer increased an risk of abnormal bone mineralization, and are linked to poor bone health in epilepsy patients. However, vitamin D is not the only determinant of bone health in children with epilepsy. Anticonvulsant medications, in addition to features and comorbidities of epilepsy and coexisting neurologic diseases, are important factors in this complex topic. We review the basic metabolism of vitamin D in terms of bone health among children with epilepsy. We also discuss the literature regarding vitamin D and bone mineral density in this population. Finally, we suggest algorithms for screening and treating vitamin D insufficiency in these patients.

Adverse endocrine and metabolic effects of psychotropic drugs: selective clinical review

The article critically reviews selected, clinically significant, adverse endocrine and metabolic effects associated with psychotropic drug treatments, including hyperprolactinaemia, hyponatraemia, diabetes insipidus, hypothyroidism, hyperparathyroidism, sexual dysfunction and virilization, weight loss, weight gain and metabolic syndrome (type 2 diabetes mellitus, dyslipidaemia and hypertension). Such effects are prevalent and complex, but can be managed clinically when recognized. They encourage continued critical assessment of benefits versus risks of psychotropic drugs and underscore the importance of close coordination of psychiatric and general medical care to improve long-term health of psychiatric patients. Options for management of hyperprolactinaemia include lowering doses, switching to agents such as aripiprazole, clozapine or quetiapine, managing associated osteoporosis, carefully considering the use of dopamine receptor agonists and ruling out stress, oral contraceptive use and hypothyroidism as contributing factors. Disorders of water homeostasis may include syndrome of inappropriate antidiuretic hormone (SIADH), managed by water restriction or slow replacement by hypertonic saline along with drug discontinuation. Safe management of diabetes insipidus, commonly associated with lithium, involves switching mood stabilizer and consideration of potassium-sparing diuretics. Clinical hypothyroidism may be a more useful marker than absolute cut-offs of hormone values, and may be associated with quetiapine, antidepressant and lithium use, and managed by thyroxine replacement. Hyper-parathyroidism requires comprehensive medical evaluation for occult tumours. Hypocalcaemia, along with multiple other psychiatric and medical causes, may result in decreased bone density and require evaluation and management. Strategies for reducing sexual dysfunction with psychotropics remain largely unsatisfactory. Finally, management strategies for obesity and metabolic syndrome are reviewed in light of the recent expert guidelines, including risk assessment and treatments, such as monoamine transport inhibitors, anticonvulsants and cannabinoid receptor antagonists, as well as lifestyle changes.

Effects of antiepileptic drug therapy on vitamin D status and biochemical markers of bone turnover in children with epilepsy

Reports of decreased serum 25-hydroxyvitamin D (25-OHD) and altered bone metabolism associated with antiepileptic drug (AED) treatment are inconsistent and predominantly restricted to adults. In this cross-sectional observational study, the aim was to evaluate the influence of AED treatment on vitamin D status and markers of bone turnover in children with epilepsy. In 38 children taking AEDs and 44 healthy control subjects, blood samples were collected to determine the levels of serum 25-OHD, intact parathyroid hormone (iPTH), calcium (Ca), phosphate (P), bone alkaline phosphatase (BAP), osteocalcin (OC) and C terminal telopeptide of type I collagen (ICTP). More than 75% of the patients were vitamin D deficient (serum 25-OHD<20 ng/mL) and 21% of the patients had an insufficient vitamin D status (serum 25-OHD=20-30 ng/mL). In the patients, the serum levels of OC (p = 0.002) and BAP (p < 0.001) were significantly increased, but ICTP (p = 0.002) concentrations were significantly decreased compared with the control group. When patients where divided into two groups according to their medication (mono- or polytherapy), significantly lower 25-OHD (p = 0.038) and ICTP (p = 0.005) levels and elevated BAP (p = 0.023) concentrations were found in patients under polytherapy. An association between 25-OHD and the measured bone markers could not be determined. Our results indicate that the prevalence of vitamin D deficiency in epilepsy patients under AED treatment is high, especially under polytherapy, and alteration markers of bone formation and resorption suggests an accelerated skeletal turnover. The routine monitoring of serum 25-OHD and vitamin D supplementation on an individual basis should be considered.

Autism and vitamin D

Any theory of autism's etiology must take into account its strong genetic basis while explaining its striking epidemiology. The apparent increase in the prevalence of autism over the last 20 years corresponds with increasing medical advice to avoid the sun, advice that has probably lowered vitamin D levels and would theoretically greatly lower activated vitamin D (calcitriol) levels in developing brains. Animal data has repeatedly shown that severe vitamin D deficiency during gestation dysregulates dozens of proteins involved in brain development and leads to rat pups with increased brain size and enlarged ventricles, abnormalities similar to those found in autistic children. Children with the Williams Syndrome, who can have greatly elevated calcitriol levels in early infancy, usually have phenotypes that are the opposite of autism. Children with vitamin D deficient rickets have several autistic markers that apparently disappear with high-dose vitamin D treatment. Estrogen and testosterone have very different effects on calcitriol's metabolism, differences that may explain the striking male/female sex ratios in autism. Calcitriol down-regulates production of inflammatory cytokines in the brain, cytokines that have been associated with autism. Consumption of vitamin D containing fish during pregnancy reduces autistic symptoms in offspring. Autism is more common in areas of impaired UVB penetration such as poleward latitudes, urban areas, areas with high air pollution, and areas of high precipitation. Autism is more common in dark-skinned persons and severe maternal vitamin D deficiency is exceptionally common the dark-skinned.

CONCLUSION

simple Gaussian distributions of the enzyme that activates neural calcitriol combined with widespread gestational and/or early childhood vitamin D deficiency may explain both the genetics and epidemiology of autism. If so, much of the disease is iatrogenic, brought on by medical advice to avoid the sun. Several types of studies could easily test the theory.

The adverse effects of antiepileptic drugs in children

Efficacy of antiepileptic drugs (AEDs) are often equivalent, hence selection of an AED is often determined by the adverse effects (AEs). The development of neurocognitive AEs is almost inevitable with use of AEDs, especially in high-risk groups. Teratogenesis with major or minor malformations is of great concern during the first trimester of pregnancy, but an increasing body of information suggests that potential neurocognitive developmental delay may also occur with use of AEDs in the latter part of pregnancy. Decreased bone mineral density has been found in adults and children receiving both enzyme-inducing AEDs and valproate, an enzyme-inhibiting drug. AEDs may influence the lipid profile, body weight, reproductive, hormonal and other endocrine functions, and sleep architecture. There are age-specific AEs related to pharmacokinetic differences that have been highlighted in this review with emphasis on the pediatric population. A classification of AEs using different parameters is also included.