The influence of age and sex on trabecular architecture and bone mineral density in three British historical populations

grantor: University of TorontoOsteoporosis has become a growing health concern in developed countries and an extensive area of research in skeletal biology. Although there is much interest in bone loss and osteoporosis in antiquity, there are many methodological concerns regarding studies of bone loss in archeological skeletons. Further, despite numerous studies of bone mass/density, few studies have measured bone quality in past populations. This research investigates age and sex-related changes in bone mineral density (BMD) and trabecular architecture in three British archaeological populations from the Roman, Medieval, and Post-Medieval periods. Individuals were divided by sex into three age categories (young, middle, old) using established osteological techniques. 5mm thick coronal sections (n = 171) from the fourth lumbar vertebra were scanned in a DEXA Piximus specialized densitometer (GE Lunar Corp.) to measure bone mineral density, and then x-rayed for image analysis of trabecular structure and connectivity. In this study BMD measurements were obtained, however, diagenesis could not be assessed without invasive methods. Further, a positive association was found between vertebral osteophytosis and BMD, indicating that degenerative joint disease can confound absorptiometric measurements. Trabecular architecture was successfully examined in the archeological samples with the use of image analysis, and provided a simple assessment of age-related change in bone quality. All the historical samples showed different age and sex-related patterns of bone loss and trabecular architecture as compared to modern populations. Although males generally showed expected bone loss in old age, females showed unusual patterns of bone loss between young and middle age and no further bone loss post-menopause. It is suggested that physical activity may explain some observations of greater bone density or structure, particularly in males, while reproductive factors likely played a key role in female bone maintenance in the past. The reproductive patterns of females in the historical samples would have created a dramatically different hormonal milieu as compared to modern females, which may have protected against bone loss and fragility.Ph.D