Gender Differences in Bone Mineral Density in Epilepsy

Bone mineral density loss in ambulatory children with epilepsy in spite of using supplemental vitamin D in Southern Iran: a case-control study

Epilepsy might have adverse effect on bone density due to underlying disease, drugs, vitamin D deficiency, immobilization and malnutrition. We investigated the bone mineral density in ambulatory vitamin-D supplemented children with epilepsy. This case-control study was conducted on 90 epileptic children aged 11.4 ± 3.3 years, and age and gender matched controls in pediatric neurology clinics of Shiraz, in Southern Iran, 2016. Anthropometric measurements, puberty, sun exposure, physical activity and biochemical variables were assessed. Bone mineral density was evaluated by dual-energy X-ray absorptiometry method. Data were analyzed by SPSS.v21. Prevalence of low bone mass in femur was more in patients (27%) than the controls (9%) (P value = 0.002). Age, weight Z score and height Z score were the most significant associated factors on lumbar BMD, BMAD, and femur BMD. Seizure duration and how it responded to anticonvulsants were the most associated factors with both lumbar and femur bone density. Sodium valproate and carbomazepin usage had negative association with lumbar Z score (beta = - 0.216, P = 0.017 and beta = - 0.336, P = 0.027, respectively). We hypothesized that epilepsy per se could affect bone density by an unknown pathophysiology, which was independent from vitamin D deficiency, effects of anticonvulsant and physical activity.

Comorbidity of childhood epilepsy

Epilepsy in children is occasionally associated with variable comorbidities although the frequency of such comorbidity is often difficult to determine. They can be divided into three categories: neurological, psychological, and physical comorbidities. The goal of the present review is to discuss the reported comorbidities of epilepsy in children. The possible mechanisms and associated risk factors-including the effect of seizure frequency and seizure control, types of epilepsy, age of seizure onset, duration of illness, and the possible detrimental effect of antiepileptic drugs-will be described.

Effects of antiepileptic drugs on bone health and growth potential in children with epilepsy

BACKGROUND

Bone health may be impaired in children with epilepsy.

OBJECTIVES

Our objective was to characterize bone mineral density (BMD) and bone growth in children receiving antiepileptic drugs (AEDs) and to assess the effects of co-morbidity, vitamin D deficiency, and type of drugs used.

DATA SOURCES

Data were sourced from PubMed, Embase, and Web of Science.

ELIGIBILITY CRITERIA

Cross-sectional, cohort, case-control, or randomized controlled trials reporting BMD or parameters of bone growth.

PARTICIPANTS

Children with epilepsy compared with controls.

INTERVENTIONS

AEDS or ketogenic diet.

STUDY APPRAISAL

The studies were evaluated by one author.

SYNTHESIS METHODS

Studies were categorized as reporting reduced BMD or not at any skeletal site as outcome. A logistic regression was performed for age, percent boys, study design, type of AED, co-morbidity or not, and signs of vitamin D deficiency/osteomalacia or not.

RESULTS

Carbamazepine and valproate were analyzed as monotherapy in 11 studies, and for both drugs a limited decrease in BMD seemed present. For oxcarbazepine, levetiracetam, phenytoin, phenobarbital, and topiramate, only one study with monotherapy was found for each drug, none of which reported decreased bone density. Polytherapy with AEDs seemed to be associated with a larger decrease in bone density than was monotherapy. Although few studies were available on bone growth, these did indicate that bone growth may be impaired among users of AEDs. Ketogenic diet may be associated with decreased bone density. The main determinant of normal BMD was absence of vitamin D deficiency/osteomalacia.

LIMITATIONS

The studies differed in skeletal sites studied and most were cross-sectional. No head-to-head comparisons of AEDs were performed. Children treated with polytherapy or ketogenic diet may have more complicated and severe disease than those treated with monotherapy. The underlying cause of epilepsy and vitamin D deficiency may contribute to impaired bone growth and density.

CONCLUSIONS

Reduced bone density, impaired bone growth, and vitamin D deficiency may be seen in children treated with drugs against epilepsy.

IMPLICATIONS

Measures to correct vitamin D deficiency, calcium intake should be taken.

Treatment of epilepsy to optimize bone health

OPINION STATEMENT

When treating a person with epilepsy, one must consider many factors in addition to the obvious need to treat the seizures. Both epilepsy itself and treatment with antiepileptic drugs (AEDs) subject one to numerous potential secondary long-term health concerns. Poor bone health is one of these concerns. Studies suggest that persons with epilepsy treated with AEDs have an increased risk of fracture, low bone mineral density (BMD), and abnormalities in bone metabolism. Multiple factors likely contribute to the increased risk. Falls during generalized tonic-clonic seizures, secondary effects of AEDs on balance, inactivity, low BMD, reduced calcium intake, reduced active vitamin D metabolites, and a genetic predisposition to low BMD may all contribute. Studies suggest a differential influence of AEDs. Phenytoin, phenobarbital, and primidone are most consistently associated with a negative impact on bone. Carbamazepine and valproate may also result in bone abnormalities, but data are mixed. Current studies suggest that lamotrigine has limited (if any) effect, but again, data are inconsistent. Other AEDs have received limited study. Screening for poor bone health includes serologic testing of vitamin D metabolites (notably 25-hydroxyvitamin D) as well as BMD testing using dual energy x-ray absorptiometry. Optimizing intake of calcium and vitamin D is important for all persons with epilepsy treated with AEDs. Although many treatments for low BMD are available, these agents have not been studied in persons with epilepsy treated with AEDs. Overall, physicians treating persons with epilepsy must consider the potential effect of having epilepsy and its main treatment, AED therapy, on bone health. For patients in whom bone health is a particular concern (eg, those with diagnosed bone disease or with significant risk factors for bone disease, including glucocorticosteroid use), it is best to avoid AEDs known to negatively affect bone. In addition, practitioners should work with other treating physicians to optimize bone health in these patients.

Prevalence and risk factors of low bone mineral density and 25-hydroxyvitamin D status in young healthy epileptic adult patients in a tropical Asian country taking antiepileptic drug

PURPOSE

Antiepileptic drugs have been reported to reduce bone mineral density (BMD) in several countries with varying prevalence but in studies with small sample size and inadequate assessment of confounders, and rarely including young adults. We sought to determine the prevalence, vitamin D status and risk factors for low BMD in young adult epileptic patients in a tropical setting.

METHODS

We prospectively examined left femoral neck and spine with dual-energy X-ray absorption. Demographic data, basic laboratory studies, history of clinical epilepsy, parathyroid hormone and vitamin D level were obtained.

RESULTS

One hundred and twenty three patients were included. The mean (+/-SD) T-score was -0.31+/-1.24 at the spine and -0.19+/-1.11 at the left femoral neck. 36% had osteopenia and 4.1% had osteoporosis at either site. Four patients had vitamin D deficiency. Vitamin D levels were not correlated with BMD. Twenty-five patients had vitamin D insufficiency. Multivariate logistic regression analysis identified low body mass index (BMI) and male sex as risk factors for low BMD at the spine and low BMI and duration of treatment as risk factors for low BMD at the left femoral neck.

CONCLUSION

Chronic use of antiepileptic drug (AED) in young adult patients is associated with low BMD.

Is the role of estrogens and estrogen receptors in epilepsy still underestimated?

The etiology of epilepsy still represents an open subject of discussions and research. Contrary to the majority of diseases for which drugs are developed following the origin of disease, epilepsy is treated symptomatically because it is perceived to have diverse causes. Recent results of oncological, neurological, developmental and biochemical studies suggest that the reproductive dysfunction in men and women, as a side effect related with antiepileptic therapy, points to the single origin of this disease. It seems that contrary to the present definition of estrogen as a compound affecting seizure susceptibility, based on causal chains: of increased estrogen levels (alcohol intake) and seizure, fact that all antiepileptic drugs are aromatase inhibitors or have estrogen binding properties, described cases of seizures in epileptic patients taking quinine as preventive therapy against malaria, impact of photic activation and sleep on estrogen level, it can be assumed that estrogen plays the leading role in the mutual origin of different types of epilepsy.

Epilepsy and hormones: a critical review

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

Progressive bone mineral content loss in children with intractable epilepsy treated with the ketogenic diet

BACKGROUND

The ketogenic diet (KD) is a high-fat, low-carbohydrate, and protein diet that effectively treats intractable epilepsy (IE).

OBJECTIVE

The purpose of this study was to measure the change in bone mineral content (BMC) in children with IE treated with the KD for 15 mo.

DESIGN

Prepubertal children >or=5 y of age with IE were eligible. A 4:1 ketogenic diet was maintained for 15 mo, and whole-body and spine BMCs were measured with dual-energy X-ray absorptiometry. Z scores were generated by comparing the children with IE with a cohort of 847 healthy children. Other measurements included demographics, anthropometry, serum 25-hydroxyvitamin D (25-OHD), intact parathyroid hormone, electrolytes, and dietary intake. All measurements were performed at baseline and at 3, 6, 12, and 15 mo. Longitudinal mixed effects models were used to analyze change in BMC over time.

RESULTS

Twenty-five children (9 girls, 16 boys) with IE [age (x +/- SD): 7.3 +/- 1.9 y] participated. Growth and bone health status were suboptimal as were serum 25-OHD concentrations and dietary intake of calcium and vitamin D. Whole-body and spine BMC-for-age both declined by 0.6 z score/y and whole-body and spine BMC-for-height declined 0.7 z score/y and 0.4 z score/y, respectively. Height declined 0.5 z score/y. Body mass index (BMI; in kg/m(2)) z score, age, and ambulation were positive predictors of BMC, which declined sharply over 15 mo of KD treatment.

CONCLUSION

Bone health in children with IE was poor, particularly for younger nonambulatory children with low BMI status. The KD resulted in progressive loss of BMC. The mechanism is unclear. Further studies are needed.