Exposure to antiepileptic drugs and the risk of hip fracture: a case-control study.
OBJECTIVE
To investigate whether the use of antiepileptic drugs (AEDs) increases the risk of hip fracture.


METHODS
We performed a case-control study using data from the Funen County (population 2004: 475,000) hip fracture register. Cases (n = 7,557) were all patients admitted to county hospitals with a hip fracture during the period 1996-2004. Controls (n = 27,575) were frequency matched by age and gender. Information on use of AEDs, other drugs, and hospital contacts was available from local registers. Odds ratios (ORs) with 95% confidence intervals (CI) for hip fracture were estimated by unconditional logistic regression.


RESULTS
Fracture risk was increased with ever use of any AED (OR: 1.31; 95% CI: 1.16-1.48). The risk was also increased with use of only enzyme inducing (OR: 1.31; 95% CI: 1.14-1.51), but not with use of only noninducing AEDs (OR: 1.03; 95% CI: 0.77-1.37). Current (OR: 1.92; 95% CI: 1.58-2.33) and recent use, as well as high daily (OR: 1.50; 95% CI: 1.24-1.82) and cumulative dose increased fracture risk, but long treatment duration or previous use did not. The risk was modified by the presence of an epilepsy diagnosis.


CONCLUSIONS
Use of AEDs modestly increases the risk of hip fracture. The risk increase is probably associated to a higher degree with a dose dependent effect on CNS with current and recent use, than with an effect on bone tissue.
Tsiropoulos
Ioannis
I
Department of Neurology, Odense University Hospital, Odense, Denmark. iotsi@dadlnet.dk
Andersen
Morten
M
Nymark
Tine
T
Lauritsen
Jens
J
Gaist
David
D
Hallas
Jesper
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000009:adverse effects*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D015986:Confounding Factors, Epidemiologic; D004827:Epilepsy / Q000188:drug therapy; D005260:Female; D006620:Hip Fractures / Q000139:chemically induced* / Q000453:epidemiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D012306:Risk; D055815:Young Adult
D000927:Anticonvulsants