Value of routine screening for bone demineralization in an urban population of patients with epilepsy

Screening and early treatment for osteoporosis: Who are we missing under age 65?

For women under age 65, varying recommendations and the need to apply clinical risk calculators can lead to underscreening for osteoporosis. The resulting undertreatment may lead to a risk of osteoporotic fractures with significant morbidity and impact on functional status. Factors that must be considered when deciding to screen a woman under age 65 include a history of fragility fractures, race, family history, body mass index, smoking, high alcohol use, and secondary causes of osteoporosis. Secondary causes of osteoporosis are much more common in younger women. These include common conditions such as glucocorticoid use, hyperthyroidism, hypogonadism, chronic kidney disease, diabetes, anticonvulsant use, rheumatoid arthritis, malabsorption, and a history of anorexia nervosa. The reasons why these conditions confer an increased risk of osteoporosis are discussed. Recommendations are provided for the clinician to be aware of when screening women under age 65 for osteoporosis and initiating treatment when indicated.

Are we responding effectively to bone mineral density loss and fracture risks in people with epilepsy?

Objective

A 2007 study performed at Montefiore Medical Center (Bronx, NY) identified high prevalence of reduced bone density in an urban population of patients with epilepsy and suggested that bone mineralization screenings should be regularly performed for these patients. We conducted a long-term follow-up study to determine whether bone mineral density (BMD) loss, osteoporosis, and fractures have been successfully treated or prevented.

Methods

In the current study, patients from the 2007 study who had two dual-energy absorptiometry (DXA) scans performed at least 5 years apart were analyzed. The World Health Organization (WHO) criteria to diagnose patients with osteopenia or osteoporosis were used, and each patient's probability of developing fractures was calculated with the Fracture Risk Assessment Tool (FRAX).

Results

The median time between the first and second DXA scans for the 81 patients analyzed was 9.4 years (range 5-14.7). The median age at the first DXA scan was 41 years (range 22-77). Based on WHO criteria, 79.0% of patients did not have worsening of bone density, while 21.0% had new osteopenia or osteoporosis; many patients were prescribed treatment for bone loss. Older age, increased duration of anti-epileptic drug (AED) usage, and low body mass index (BMI) were risk factors for abnormal BMDs. Based on the first DXA scan, the FRAX calculator estimated that none of the patients in this study had a 10-year risk of more than 20% for developing major osteoporotic fracture (hip, spine, wrist, or humeral fracture). However, in this population, 11 patients (13.6%) sustained a major osteoporotic fracture after their first DXA scan.

Significance

Despite being routinely screened and frequently treated for bone mineral density loss and fracture prevention, many patients with epilepsy suffered new major osteoporotic fractures. This observation is especially important as persons with epilepsy are at high risk for falls and traumas.

Hyponatremia and metabolic bone disease in patients with epilepsy: A cross-sectional study

AIM

Patients with epilepsy frequently develop hyponatremia due to the treatment with antiepileptic drugs and have an increased risk of developing metabolic bone disease. Hyponatremia is known to be associated with osteoporosis. The aim of the study was to investigate the association between hyponatremia and osteoporosis in patients with epilepsy.

METHOD AND MATERIAL

This cross-sectional study included patients with epilepsy from a tertiary epilepsy out-patient clinic in Denmark, who had a Dual Energy X-ray Absorptiometry scan performed and an accompanying plasma sodium (p-Na) measured prior to or a maximum of 14 days after the scan. Information regarding the patients' health and medical conditions were obtained from their medical reports.

RESULTS

A total of 695 patients (females 53.8%, age 49 (34:63) years (median (quartiles)) were included. 10.4% had hyponatremia (p-Na ≤ 135 mmol/L). The hyponatremic patients had significantly lower T-scores in the lumbar spine, femoral neck and total femur (all p < 0.023) and the odds ratio of osteoporosis (T-score < -2.5) was significantly increased (2.91 (1.61-5.27) (95% confidence interval) (p = 0.001)). When adjusting for potential confounders the patients with moderate and severe hyponatremia (p-Na < 129 mmol/L) had a significantly lower mean T-score in the lumbar spine (p = 0.030).

CONCLUSION

We conclude that hyponatremia is common in patients with epilepsy and that moderate and severe hyponatremia is independently associated with decreased bone mineral density in the lumbar spine. Therefore, hyponatremia in a patient with epilepsy should warrant further examination of the patient for bone loss and 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.

Bone Health in Patients with Epilepsy: A Community-based Pilot Nested Case-control Study

Background:

Antiepileptic drugs (AEDs) adversely affect bone health and there are reports describing association of alternations of bone and mineral metabolism in epileptic patients.

Objectives:

This study was undertaken to evaluate the bone profile (bone mineral parameters and bone mineral density [BMD]) of patients with epilepsy and compare them to their age-, gender-, and socioeconomic status-matched healthy controls in a community.

Materials and Methods:

This was a nested case–control study conducted in fifty individuals, which included 25 cases (age above 18 years and on AEDs for at least 3 years) for which 25 controls were selected from the same community. Bone mineral parameters (serum calcium, proteins, phosphorous, alkaline phosphate, parathyroid hormone, and Vitamin D) and BMD were measured.

Results:

There was significant hypocalcemia (P = 0.003), hypoproteinemia (P = 0.014), hyperparathyroidism (P = 0.048), and increased levels of serum alkaline phosphatase (P = 0.019) in cases as compared to controls. The difference was insignificant in the serum levels of Vitamin D and phosphorous among both the groups. Vitamin D was significantly low in female patients as compared to males (P = 0.043). There was no significant difference in BMD at the lumbar spine and femur neck among both the groups. Mean duration of epilepsy was longest in patients with osteoporosis (23.6 years), and increasing duration of epilepsy was associated with reduction in age- and sex-corrected total BMD mean Z-score anteroposterior spine. There was negative correlation between cumulative drug load and T-score of patients with epilepsy.

Conclusion:

Patients on long-term AED treatment have altered bone profile as evident from biochemical parameters and reduced BMD. There is a need for more extensive research and that too on a larger sample size.

Survey of risk factors for osteoporosis and osteoprotective behaviors among patients with epilepsy

The prevalence of risk factors for osteoporosis in persons with epilepsy, patients' awareness of their risk, and their engagement in osteoprotective behaviors were assessed in this study. Two hundred and sixty patients with epilepsy (F=51.5%, average age=42) completed a survey tool. Of 106 patients with a dual energy X-ray absorptiometry (DXA) result, 52% had low bone mineral density, and 11% had osteoporosis. The results suggest that the majority of patients with epilepsy do not engage in bone-protective behaviors. Those who have undergone a DXA scan may be more likely to take calcium and vitamin D supplementation compared with those who did not undergo a DXA scan, but they do not engage in other osteoprotective behaviors. Many patients did not accurately report their DXA results, indicating that better patient education is warranted.

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.

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.

The association between CYP 2C9 polymorphism and bone health

PURPOSE

There is a strong scientific rationale to support the view that cytochrome P450 (CYP P450) enzyme-inducing AEDs induce bone loss in patients with epilepsy. However, no study has investigated the association between CYP 2C9 polymorphism and bone mineral density (BMD), 25-hydroxyvitamin D or parathyroid hormone levels in patients with epilepsy. This study sought to determine the association between BMD and CYP 2C9 polymorphism.

METHODS

Ninety-three patients taking phenytoin as monotherapy were examined for CYP 2C9 polymorphism, vitamin D level and parathyroid hormone level and underwent basic chemistry testing. The bone mineral density of the lumbar spine and left femur were measured using dual-energy X-ray absorptiometry.

RESULTS

The results indicated that about 18.3% of the patients with epilepsy were positive for CYP2C9*3. Furthermore, bone mineral density was associated with CYP 2C9 polymorphism epileptic patients. Specifically, patients with 2C9 polymorphism had higher T-scores and Z-scores of the femoral neck (p=0.02 and 0.04, respectively), but not of the lumbar spine (p=0.27 and 0.06, respectively). There was also a trend of having higher serum PTH levels and statistically significantly lower 25-hydroxyvitamin D levels in patients with wild type than in those compared with CYP 2C9 polymorphism (p=0.05 and 0.03, respectively). Additionally, the patients with CYP 2C9 polymorphism had higher plasma levels of phenytoin, particularly when compared with those with wild type (p=0.01). However, there was no association between serum levels of phenytoin and low BMD at femoral neck or lumbar spine.

CONCLUSION

CYP 2C9 polymorphism is associated with higher BMD, independent of plasma levels of phenytoin.

Brains, bones, and aging: psychotropic medications and bone health among older adults

Psychotropic drugs are a crucial element of treatment for psychiatric disorders; however there is an established association between many classes of psychotropic medications and fracture risk among older adults, and growing evidence that some classes of medications may also impact bone mineral density (BMD). In this paper we review recent epidemiologic research on the association between psychotropic medications and osteoporosis, and discuss current controversies and unresolved issues surrounding this relationship. Key areas in need of focused inquiry include resolving whether the apparent association between psychotropic medications and BMD is due to confounding by indication, whether this relationship differs for men and women, and whether the implications of these medications for bone health vary over the life course. Clinical research to delineate the risk/benefit ratio of psychotropic medications for older adults, particularly those who are at high risk for fracture, is also needed to facilitate prescribing decisions between patients and physicians.

Epilepsy: fractures and the role of cumulative antiepileptic drug load

BACKGROUND

An association between antiepileptic drugs (AEDs), low bone mineral density (BMD), fractures, and abnormalities in bone metabolism has been suggested for a longer period, although conclusive evidence has not been reported. We aimed at studying patient characteristics in a high-risk population.

METHODS

All adult patients from a residential unit of a tertiary epilepsy center who were diagnosed with osteoporosis and consequently treated with a bisphosphonate at that moment were included. Correlations between reported fractures and patient characteristics were explored.

RESULTS

Of the total population of 261 adult patients, 54 patients were included resulting in a high prevalence rate of 21% osteoporosis in this population. The number of fractures correlated significantly with ambulatory status (r = -0.269, P = 0.05), drug load (r = 0.286, P = 0.04), and current number of AEDs (r = 0.283, P = 0.04). Correlations could not be provided for individual drugs in our population as only a minority was on monotherapy and even less patients had always been on monotherapy of the same antiepileptic drug. Linear regression analysis showed that cumulative drug load (defined by a surrogate parameter: the total duration of epilepsy multiplied by the number of AEDs) was the dominant factor explaining the occurrence of fractures.

CONCLUSION

In this high-risk population, we obtained a positive and strong correlation between the occurrence of fractures in a diagnosed population with osteoporosis and the cumulative drug load of AEDs. This effect seems general, independent of the type of AEDs that were used.

General surgery among long-term residents with and without active epilepsy at the Kork Epilepsy Centre - a prospective comparative one-year survey

BACKGROUND/AIMS

We prospectively assessed the frequency, type, severity and cause of treatment among the long-term residents of the Kork Epilepsy Centre in the year 2005.

METHODS

All long-term residents were exclusively referred to the general surgeon practicing on the campus. Patients were divided into 2 groups comprising 285 patients with active epilepsy and 53 controls who either never had epileptic seizures or have remained seizure free for at least 4 years.

RESULTS

The 1-year incidence of injuries was 54.2% among the active epilepsy group and 36.8% among controls (p = 0.0275). Several admissions due to differing reasons occurred in 16.8% of people with active epilepsy and in 7.5% of the controls (not significant). More than 2 admissions due to various reasons only occurred in patients with active epilepsy (range 3-9). Of all injuries, 41.3% were directly related to seizures. Among patients with active epilepsy, the 3 most frequent injuries were lacerations, bruises and fractures (29.6, 17.0 and 11.7%, respectively).

CONCLUSION

According to this prospective study, active epilepsy turned out to be a significant risk factor for injuries under homogenous patient and observer conditions.

Screening bone mineral density in epilepsy: a call to action, but what action?

Value of Routine Screening for Bone Demineralization in an Urban Population of Patients with Epilepsy. Lado F, Spiegel R, Masur JH, Boro A and Haut SR. Epilepsy Research 2008;78( 2 – 3 ):155–160.

Background

Reduced bone mineral density (BMD) is increasingly recognized in patients receiving antiepileptic drug therapy. The precise prevalence is not known due to variability across populations studied. We set out to characterize the prevalence of abnormal BMD in an urban population of patients with epilepsy with the intent to determine the value of routine BMD screening.

Methods

We performed a cross-sectional study of 130 consecutive patients seen thorough our Comprehensive Epilepsy Center. BMD was measured using dual X-ray absorptiometry and was reported as T-score and Z-score. Additional information collected for each patient included age, race, gender, current and prior AEDs, ambulatory state, menopausal state, concomitant medications potentially associated with reduced bone mineralization, and comorbid illness potentially associated with reduced bone mineralization. Associations between reduced bone mineralization and variables were tested for significance using Fisher's exact test, Student's t-test, and Wilcoxon rank sum test.

Results

The average age of the entire study population was 43.5 (±12.5) years. Fifty-five percent of patients had T-score less than or equal to −1, the WHO criterion for osteopenia in postmenopausal women. The prevalence of Z-scores less than −2.0 was 15%, which is more than sixfold greater than expected. The markers for decreased BMD included older age or menopause in women, longer duration of therapy, and a history of use of phenytoin or phenobarbital. Assisted ambulation was also associated with low BMD.

Conclusion

Our results indicate that reduced bone mineralization is prevalent and a significant health concern in an urban population of patients with epilepsy. Because of the high prevalence of reduced bone mineralization reported in numerous studies including this study, routinely screening for reduced bone mineralization is warranted in patients receiving anticonvulsant therapy. Bone Health in Young Women with Epilepsy after One Year of Antiepileptic Drug Monotherapy. Pack AM, Morrell MJ, Randall A, McMahon DJ and Shane E. Neurology 2008;70(18):1586–1593.

Objective

Antiepileptic drugs (AEDs) may have adverse effects on bone mineral density (BMD) and metabolism. We previously reported biochemical evidence of increased bone turnover in premenopausal women with epilepsy on phenytoin monotherapy compared with those on carbamazepine, lamotrigine, and valproate. We therefore hypothesized that rates of bone loss would be higher in young women treated with phenytoin.

Methods

Ninety-three premenopausal women with epilepsy receiving a single AED (carbamazepine, lamotrigine, phenytoin, or valproate) participated. Subjects completed nutritional and physical activity questionnaires. Biochemical indices of bone and mineral metabolism and BMD of the proximal femur and lumbar spine were measured at baseline and 1 year.

Results

Participants reported high calcium intake (>1,000 mg/day) and were physically active. Significant loss (2.6%) was seen at the femoral neck in the phenytoin group. BMD remained stable in the other AED groups. Bone turnover markers and calciotropic hormones were unchanged after 1 year in all groups except for a significant decline in urine N-telopeptide in the phenytoin group. In women receiving phenytoin, lower serum 25-hydroxyvitamin D concentrations were associated with higher parathyroid hormone, bone alkaline phosphatase, and urine N-telopeptide levels, a biochemical pattern consistent with secondary hyperparathyroidism and increased remodeling.

Conclusion

In this study, young women treated with phenytoin had significant femoral neck bone loss over 1 year. In contrast, those treated with carbamazepine, lamotrigine, and valproate did not have detectable adverse effects on bone turnover or bone mineral density. These results raise concerns about the long-term effects of phenytoin monotherapy on bone in young women with epilepsy.

Association of epilepsy and comorbid conditions

Comorbid health conditions are common among people with epilepsy. Proposed explanations for this association include the possibility that first, epilepsy (including its treatment) causes the comorbid condition; second, the comorbid condition (including its treatment) causes epilepsy; or third, a common pathogenic mechanism mediates the co-occurrence of epilepsy and the comorbid condition. It is unlikely that a single explanation will suffice for all of the epilepsy comorbid conditions. Determining the basis of the association between epilepsy and its comorbid conditions has important implications for diagnosis and management. In this paper, we discuss this issue in the context of five common epilepsy comorbid conditions: bone health and fractures, stroke, depression, migraine and attention-deficit hyperactivity disorder. Current findings, research limitations and future directions of research efforts are discussed.

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.