A glimpse from the past: osteoporosis and osteoporotic fractures in a portuguese identified skeletal sample

The diachronic variation of etiological factors, like longevity or diet, affected the prevalence of osteoporosis and the so-called osteoporotic fractures in the past. As such, it is important to understand the epidemiology of this disease in historical populations; with behaviors and customs that were unalike the modern westernized lifestyle. Objectives: The main objective of this study is to characterize the epidemiological patterns of osteoporosis and related fractures in an identified Portuguese skeletal sample from the mid 19th - early 20th centuries. Materials and methods: The sample studied comprised 196 skeletal individuals with known sex and age-at-death, housed at the University of Coimbra. Bone mineral density (BMD) was evaluated in the proximal femur through dual X-ray absorptiometry and osteoporotic fractures were recorded according to clinical and paleopathological protocols. Results: BMD decreased significantly with age-at-death, both at the ROI «Total hip» and the ROI «Neck». At the «Total hip», peak bone mass (PBM) was achieved early (20-29 years age group) in both sexes. In the study-group as a whole, BMD was significantly higher in males when compared to females. As expected, the prevalence of osteoporosis in the proximal femur is higher in women and rises steeply with age. Comparisons with two modern Portuguese samples showed an equivalent pattern of BMD reduction. Nonetheless, BMD is usually lower in the skeletal sample. Women with osteoporosis had a much larger probability of showing a fragility fracture than women diagnosed with «normal» BMD or osteopenia. Conclusions: In spite of enormous lifestyle differences, the epidemiological pattern of bone mass decrease in a Portuguese skeletal sample is strikingly similar to the ones observed in modern populations. This study adds further data to the recent notion that osteoporosis is a disease with deep roots in the past.