Magyar László szerk.: Orvostörténeti közlemények 133-140. (Budapest, 1991-1992)

KISEBB KÖZLEMÉNYEK — STUDIES AND LECTURES - Raptis, George: Paleopathological Investigation of Osteoporosis with Dual Energy X-ray Absorptiometry

PALEOPATHOLOGICAL INVESTIGATION OF OSTEOPOROSIS WITH DUAL ENERGY X-RAY ABSORPTIOMETRY. VALIDATION OF BONE MINERAL CONTENT DETERMINATION IN ANCIENT SPECIMENS GEORGE RAPTIS INTRODUCTION Osteoporosis is a metabolic bone disease which results in loss of skeletal mass without alteration of the composition of bone [16, 43]. Bone strength is correlated with its mineral content (e.g. calcium salts) and presumably the most important clinical consenquence of osteoporosis, fracture, occurs most frequently in persons with osseous demineralization [35]. Evidence of osteopenia, i.e. subclinical, non-manifest diminution of bone mineral content has a prevalence rate varying with measurement technique, anatomic location and part of the bone being analyzed [16, 42]. Ethnic, age-, gender-, and nutritional-factors have been implicated as determining the parameters of initial bone mass and rate of bone loss [25,27,43,48]. While research projects are sponsored worldwide concentrating on the etiology and epidemiology of osteoporosis, comparably little understanding of its causes and mechanisms has been furnished so far [25,45]. AIM OF STUDY An alternative approach to examining the factors that influence bone mineral content is to study the remains of ancient populations. Osteoporosis as a disease is particularly easy to be paleopathologically investigated since the bones of a deceased individual are the long-standing evidence of his or her mineral status, besides diseases with osseous participation [46]. Paleopathology is a broad discipline which embraces anthropology, archeology, and paleontology [5, 7, 14, 15, 17, 26, 30, 54, 59]. It was proposed to designate the study of all evidence of pathological conditions found in the remains of animals or people [49, 50]. Its course runs paralell to that of history of medicine in that paleopathology contributes to a deeper understanding of ontogeny of disease, the prevalence and variability thereof in the past [3, 4, 38, 44, 45, 50, 57, 58]. Thus medical questions are illuminated in a specific timeperiod by a different angle, in a multidisciplinary way, and more accurately that by historical [e.g. literary, 1, 2, 56] and pure archeological evidence [4, 40]. With the paleopathological approach the epidemiology of osteopenia may be evaluated in populations of a different nutritional, climatic, and social setting that corresponding present day societies. Ethnic, that is genetic, differences must be taken into account, as well as the overt, pre-mortem, osteoporotic lesions, e.g. deformations of lumbar vertebrae and fractures of femoral neck in the living [7, 47]. Two questions may be addressed in this way. Firstly, the correlation of bone density with age [48], sex [35], and degree of physical activity [16] can be assessed assuming a known or determined dietery pattern. Secondly, these results could be further analyzed in view of the special nutritional, ecological, and demographical characteristics of the population under study. Apparently, a necessary prerequisite of the above is an accurate and reliable measurement of bone mineral content [31]. The present study was undertaken in order to evaluate the reproducibility and validity of the application of dual energy X-ray absorptiometry to measuring ancient bones. The principle of absorptiometry encompasses the determination of the relative calcium concentration with high precision analysis of the process of energy absorption as monochromatic (single wave-length) X-rays pass through the material under study. A limited scale approach was implemented so as to ensure completely standardized experimental