Progressive bone deficit in epilepsy.
OBJECTIVE
Chronic treatment with antiepileptic medication is associated with reduced bone mineral density (BMD), which may underlie the two- to sixfold increase in fracture rates observed in patients with epilepsy. The objective was to determine the timing of the BMD deficit in ambulatory children with epilepsy.


METHODS
A cross-sectional evaluation was conducted in 82 ambulatory children aged 6 to 18 years (12.4 +/- 3.3 years) with epilepsy for <1 year (n = 18), 1 to 5 years (n = 37), and 6 or more years (n = 27). Controls were 32 healthy children aged 12.8 +/- 2.6 years. Age- and sex-corrected total body BMD Z-score was measured.


RESULTS
Total BMD Z-score was lower in children with epilepsy (0.10 +/- 0.96; CI = -0.08, 0.34) compared to controls (0.57 +/- 0.74; CI = 0.3, 0.84; p = 0.03). Increasing duration of epilepsy was associated with a progressive reduction in BMD compared to controls (Spearman r = -0.197; p = 0.03). Compared to controls, those with epilepsy for 1 to 5 years had a mean BMD Z-score of 0.13 +/- 0.78 (CI = -0.13, 0.39; p = 0.04) and in those treated for 6 or more years BMD was 0.06 +/- 1.11 (CI = -0.38, 0.5; p = 0.04). For those with epilepsy for <1 year BMD was 0.23 +/- 1.1 (CI = -0.31, 0.77; p = 0.21).


CONCLUSIONS
Children treated for epilepsy sustain significant bone mineral density (BMD) deficit compared to controls during the initial 1 to 5 years of treatment which progressively worsens thereafter. This progressive BMD deficit may be a contributing factor to the increased fracture risk observed in patients with epilepsy and may accelerate aging-related osteoporosis.
Sheth
Raj D
RD
Department of Neurology, University of Wisconsin-Madison, 600 Highland Ave-H6/574 CSC, Madison, WI 53792-5132, USA. sheth@neurology.wisc.edu
Binkley
Neil
N
Hermann
Bruce P
BP
D000293:Adolescent; D017668:Age of Onset; D000375:Aging / Q000235:genetics; D000927:Anticonvulsants / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects* / Q000235:genetics; D001846:Bone Development / Q000187:drug effects / Q000235:genetics; D001851:Bone Diseases, Metabolic / Q000139:chemically induced* / Q000235:genetics* / Q000503:physiopathology; D002648:Child; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D018450:Disease Progression; D042241:Early Diagnosis; D004827:Epilepsy / Q000150:complications* / Q000188:drug therapy* / Q000235:genetics; D005260:Female; D050723:Fractures, Bone / Q000139:chemically induced / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D008297:Male; D012307:Risk Factors
D000927:Anticonvulsants