| Abstract: |
Significant age-associated bone loss and related fragility fractures, or osteoporosis, are prevalent in contemporary populations due to increased longevity. Populations of European descent are more susceptible to osteoporosis than others, particularly African populations, and there is a higher incidence of osteoporosis in females than in males. Previous research has shown that archaeological populations had relatively low prevalence of fragility fractures. In this thesis, I investigate age-associated bone loss in an Imperial Roman cemetery population from the Isola Sacra Necropolis (A.D. 2<super>nd </super>3<super>rd</super> centuries) near Rome. The population was urban and European, and the individuals were inhabitants of <italic>Portus Romae</italic>, an important Roman port during the peak of the Roman Empire. Both microscopic and macroscopic analyses were employed in the study to quantify measures of bone mass and bone loss in 149 adult individuals ranging in age from 2050+ years. Bone histomorphology, the quantitative study of skeletal tissue, was used to estimate the bone remodeling parameters and the mechanism of bone loss in the cortical rib and femur midshaft sections. Cortical dimensions of the anterior superior iliac crest were measured. Rib and femur midshaft diaphyseal cross-sectional areas were quantified to observe the progression of bone loss across age groups. Femur midshaft diaphyseal cross-sectional geometry was measured to determine second moments of area, which are measures of bone rigidity. Age- and sex-related patterns of bone loss, and intra-skeletal variability in the cortical histomorphometrics of the skeletal elements collected from the same individuals were explored during the analyses. Results indicate that the Imperial Romans had age-related bone loss, more so in females than in males, which is a similar pattern to that observed in modern populations. Males increased in bone strength with age, and were able to better maintain their bone mass and lose less bone than females did, probably due to more rigorous physical activities, as well as exemption from pregnancies, lactation, and menopause, which can exacerbate bone loss. Rib and femur cortical histomorphometrics differed significantly due to different bone turnover rates or a later effective age of adult compacta in the femoral cortex. Iliac crest results suggest that the anterior superior iliac crest may not be a representative site for bone loss in the skeleton and another skeletal site should be used in clinical practice. When compared to modern European- and African-American populations, the ancient Romans and African-Americans were more similar in that they were better able to maintain bone mass with age, and had slower bone turnover rates than modern European-Americans. These findings suggest that different lifestyles in the past, such as higher physical activity levels, may have had beneficial effects on bone and served as protective barriers against significant bone loss.
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