Introduction: Osteoporosis is a systemic disease of the skeletal system characterised by reduced bone strength leading to increased risk of fracture. Bone strength is a combined derivative of bone mineral density (BMD) and of bone tissue quality. Osteoporosis is a serious medical problem because of its complications, most frequently manifesting itself in spine fractures, fractures of distal sections of the forearm and, in later periods of life, hip fractures. Reduced BMD is an independent risk factor of osteoporosis. The goal of the study was an evaluation of bone mineral density of the population inhabiting the micro-region of Brześć Kujawski from the 11^th century until the beginning of the 19^th century.
Material and methods: Human bones obtained from archaeological excavations at four archaeological sites: Kolonia (11^th–13^th centuries), SBK-4 (12^th–16^th centuries), Fara (14^th–17^th centuries) and Święty Duch (16^th–19^th centuries) and from the collections of the Katedra of Anthropology of the University of Łódź were subjected to study. Bone mineral densities of the skeleton populations were compared with those of the control group, namely the present living population of the Łódź Province. The incidence of osteoporosis was evaluated by densitometric assessment, which was performed by dual energy X-ray absorptiometry (DXA) on a DPX device (LUNAR, USA).
Results: The densitometric measurements performed enabled differences to be identified in the mineral density of the osseous tissue. The skeletal groups studied were characterised by a significantly higher mean BMD than the contemporary living population. Changes in BMD indicative of osteopenia prevailed in women.
Conclusions: On the basis of the results obtained it cannot definitively be stated that the skeletal groups studied, despite their significantly higher BMD, were affected by a lower risk of osteoporosis and its complications. A continuation of studies on the mineral content of bones and on the relationship between the mineral content and bone mineral density is required.