Prevalence of low bone mineral density in residents of a long-term facility care centre for people with refractory epilepsy, intellectual disability and long-term use of anti-epileptic drugs: a cross-sectional cohort study.

Chronic treatment with anti-epileptic drugs (AEDs) is associated with reduced
bone mineral density (BMD), which may underlie the two to sixfold increase in
fracture rates observed in patients with refractory epilepsy. In patients with
an intellectual disability (ID) low BMD is found more frequently than in a
general population. In patients with an ID ánd epilepsy, multiple risk factors
for low BMD and increased fracture rates are present creating a high risk for
this specific subpopulation. In spite of the growing body of literature which
strongly recommends screening as standard part of good clinical practice of
patients with epilepsy, routine screening for BMD loss among people with an ID
and epilepsy has not been practiced, partly because the exact prevalence of low
BMD in patients with ID and epilepsy is not known.

The main objective of this study is to determine the prevalence of low BMD
measured with dual-energy X-ray absorptiometry (DEXA) and quantitative
ultrasonography (QUS) in Providentia (a residential care facility for persons
with refractory epilepsy often in combination with an intellectual disability)
and to identify risk factors for low BMD.

Observational cross-sectional cohort study.

All patients are seen in their own living environment in Providentia during one
on-site visit. Using a standardized data collection form information is
abstracted from each chart. Actual weight and height will be measured if not
available in patient*s chart. A questionnaire to estimate patient*s daily
calcium intake over 3 days is filled in cooperation with the patient*s direct
caretakers. Each patient will have one blood sample tested. Also a DEXA scan
and a QUS for measuring BMD is done. QUS is a non-invasive bone measuring
method without any radiation involved. DEXA is also non-invasive and has a very
low radiation burden, approximately 10 times lower than a chest radiograph [7].
The burden and risks associated with participation in this study are therefore
considered minimal. The patient*s general physician is notified if osteoporosis
is found. This to ensure further investigation, risk assessment and treatment
of the osteoporosis in the best interest of the patient.
In people with refractory epilepsy and ID multiple risk factors are present for
developing BMD loss and associated fractures, and are therefore considered a
subpopulation at an especially high risk. Consequently, results of
investigations in patients with epilepsy without ID cannot be extrapolated to
this specific high risk group.
The data on epilepsy, AEDs and low BMD justify systematic screening with DEXA
and laboratory investigations. Taking into account the growing body of
evidence, nowadays screening is strongly advised by many authors in the field.
If this research project would not take place, all the residents of Providentia
would still be screened for the presence of osteoporosis and osteopenia with a
DEXA scan and laboratory investigations.
Therefore, the specific extra measurements that will be done for this research
project are:
1) an ultrasonography of the calcaneus (non-invasive, no radiation load,
duration of 10-20 seconds),
2) drawing of 2 tubes of blood extra (the venapunction will take place at the
same time of the 6-monthly blood check ups of the residents, so no extra
venapunction will be done).
3) a food frequency questionnaire will be completed in cooperation with the
direct caretakers of the residents.
All the 3 above mentioned measurements will take place during an on-site visit
on the residential facility care centre.

Therefore the burden associated with participation is considered low and the
all the three measurements necessary for this research project are of
non-invasive nature.

The results of these measurements will facilitate the establishment of
standardized screening and treatment protocols for specific at risk
subpopulations and help to achieve the long-term goal of preventing low BMD in
this particular population.