biologia - Studia

R. TOROK OANCE, V. NICULESCU, M.N. FILIMON
per unit of surface (g/cm 2 ) or per volume unit (g/cm 3 ). The planimetric estimation of a
bone mineral density is realized by using the dual energy X-ray absorptiometry.
The analysis of the bone mineral density is essential for the osteoporosis
diagnostic of certainty. Osteoporosis is the most frequent bone disease (Werner and
Vered, 2000) which affects millions of people around the world, and its prevalence
is increasing as a result of population ageing. In 1994, the World Health Organization
defined osteoporosis as a disease characterized by reduced bone mass and
deterioration of the bone micro architecture, with a resulting increase in bone
fragility and an increased risk of fracture.
Given the fact that the microarchitectural deterioration cannot be directly
measured, the World Health Organization has recommended that the osteoporosis
diagnosis should be done by measuring the bone mineral density with the help of
the dual energy X-ray absorptiometry. The bone mineral density (BMD) values can
be quantified in g/cm 2 or can be converted into T-score and Z-score, respectively.
Thus, in what concerns the reduction in bone mass, the following diagnostic
categories have been established: normal BMD, corresponding to a T-score with a
standard deviation of -1 or greater, osteopenia, corresponding to a T-score with a
standard deviation between -1 and -2.5, and osteoporosis, corresponding to a T-score
with a standard deviation of -2.5 or below.
In the last fifteen years, a major progress has been made in understanding,
preventing and treating osteoporosis. This progress is a result of the new technologies,
which allowed for accurately measuring the bone mineral density and for introducing
efficient treatments, which reduced the incidence of osteoporotic fractures.
Oftenly osteoporosis goes undiagnosed and untreated; the fact that, frequently,
this disease does not manifest itself clinically until a bone fracture occurs contributes to
this situation. The identification of those individuals with an increased risk and the
carrying out of a prevention treatment are extremely important, because they can lead
to a decrease in morbidity and mortality.
The purpose of this paper is to analyze the modification of the bone mineral
density and of the T-score and Z-score according to age and region of BMD
determination. The significance of this analysis resides in the fact that the appearance
of this disease is directly connected with the decrease of the bone mineral density.
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Materials and methods
The present paper is based on the analysis of the results of the
osteodensitometric investigation conducted on 361 patients who had been diagnosed
with primary or secondary osteoporosis (Table 1). The osteodensitometry was
performed at the Timişoara Clinical Hospital no. 1, with the help of a Hologic QDR
apparatus, Delphi W model. The investigation was performed at the hip bone and
at the vertebral column, and the following parameters have been analyzed: bone
mineral content, bone mineral density, T-score and Z-score.