Bone mineral density in archaeological populations of Norway: Temporal patterns of bone loss related to age, sex, and socioeconomic status in the 8th - 19th centuries AD

• Main Author: Brødholt, Elin T
• Format: Dissertation
• Language: English

Osteoporosis has a high incidence rate in Norway and is among the most common conditions among elderly Norwegians. Clinically, osteoporosis is associated with reduced bone mineral density (BMD), typically assessed by Dual Energy X-Ray Absorptiometry (DXA). Bone loss is an age-related and postmenopausal phenomenon that displays genetic variability. There is scarce information about the prevalence of osteoporosis and patterns of bone loss in past populations of Norway. Few studies are conducted, yielding diverse results without consistent trends. Furthermore, it is unclear to what extent the reported BMD variation is linked to social inequality. The present thesis aims to fill this knowledge gap by investigating the long-term historical pattern of BMD variation in past populations of Norway by assessing BMD in skeletal remains from the 8th to 19th century AD as an indicator of health and socioeconomic status (SES), in relation to age, sex and stature patterns. Our results revealed significant BMD variation through Norway's prehistoric and historical periods. We found that BMD increased significantly from the Late Iron Age to the medieval period, followed by a significant decline from the medieval to the post-Reformation period. Overall, our findings indicate a gradual transition towards a modern pattern of late bone loss seen in the contemporary Norwegian population. In addition, the patterns of age-related bone loss were diverse, with substantial temporal changes, and the bone loss often exceeded that observed in the population today. Furthermore, our findings indicate that femur neck BMD may be a valuable indicator of SES: individuals of high status had significantly higher BMD than individuals from the parish population. In addition, we demonstrated that parish population females had a significantly higher occurrence of osteopenia and osteoporosis than high-status females, possibly related to a lower attained peak BMD in childhood.