Clinical Trial Summary
In industrialized countries, it is estimated that around 10% of the population suffers from
nephrolithiasis (NL). Numerous recent epidemiological studies report that the prevalence and
incidence of NL continue to increase, with a prevalence that has nearly doubled over the past
two decades. A patient who presented with a first episode of renal lithiasis has an estimated
recurrence rate of nearly 50% at 5 years in adults. It is therefore wiser to consider NL as a
chronic pathology and not as a simple isolated attack of painful crisis. NL therefore
represents a real public health problem with a significant impact on the quality of life of
patients, with considerable socio-economic repercussions.
In clinical practice, calcium lithiasis is the most common and occurs in 90% of cases.The
stones mainly consist of calcium oxalate (whewellite, weddellite) but also calcium phosphate
(carbapatite, brushite).
One of the risk factors for calcium lithiasis is the over-saturation of urine with calcium,
which can lead to crystal formation.
The most common metabolic abnormality found in patients with NL is hypercalciuria.It is
defined as an increased excretion of urinary calcium.We can first distinguish hypercalciuria
secondary to another pathology such as primary hyperparathyroidism, sarcoidosis, distal
tubular acidosis, hypervitaminosis D, immobilization... from idiopathic hypercalciuria (HI),
at the origin of so-called primary calcium lithiasis.HI is estimated to affect 30-60% of
adults with NL.
Idiopathic hypercalciuria is associated with low bone mineral density. Patients with NL have
significantly lower T-score values in the vertebrae, hips, and femoral necks.Patients with NL
have an increased risk of fractures and are 4 times more likely to develop osteoporosis. It
is currently proposed that idiopathic hypercalciuria may be the cause of the decrease in bone
mineral density in lithiasis patients.This bone demineralization appears to be associated
with an increase in vascular calcifications.These, like NL, are believed to be linked to
extra-osia calcium deposits.There is an inverse relationship between bone mineral density and
arterial wall thickness (partly due to vascular calcifications) suggesting a relationship
between arteriosclerosis and osteoporosis. This relationship would be much more pronounced in
lithiasis women. In addition, several observations report an increase in cardiovascular
morbidity in people with NL.
NL should therefore be seen as a systemic disease and is also associated with several
pathologies such as: metabolic syndrome, arterial hypertension, diabetes and cardiovascular
diseases.
To the knowledge of the investigators, no statistical data concerning the prevalence of
vascular calcifications and bone demineralization in the population of lithiasis patients in
Belgium has been published to date.
In this context, the aim of this study is to assess the prevalence of vascular calcifications
(early state of arteriosclerosis) as well as the bone mineral density in the lithiasis
population followed at the Brugmann University Hospital and with idiopathic hypercalciuria.
