Bone Microstructure and Changes in Tissue Mineralization Throughout Adulthood
Total Page：16
File Type：pdf, Size：1020Kb
Bone Microstructure and Changes in Tissue Mineralization throughout Adulthood by Amy Catherine Beresheim A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Department of Anthropology University of Toronto © Copyright by Amy Catherine Beresheim 2018 Bone Microstructure and Changes in Tissue Mineralization throughout Adulthood Amy Catherine Beresheim Doctor of Philosophy Department of Anthropology University of Toronto 2018 Abstract This research aims to explore the global variability in the structural and material properties of mid-thoracic ribs within a large (n=213) sample of known age, sex, and government “race” designation from apartheid South Africa [DOD 1967-1998]. Most individuals in the study sample were non-white, and inferred to be of poor socioeconomic status. Using linearly polarized light microscopy (LPLM) on the full sample, and back-scattered scanning electron microscopy (BSE-SEM) on a subset (n=143), histomorphometric parameters, and the average tissue mineralization of the cortical and trabecular bone compartments were assessed in photomontages of transverse rib cross-sections. The influence of body size on bone mass and histomorphometry was first considered. Tissue-level changes were then interpreted in a biosocial context, exploring variation associated with adverse apartheid living conditions and adult life history. Body size does not appear to correlate with either bone mass or histomorphometry, suggesting that size-standardization may not be necessary in studies of rib bone microstructure. Compared to the women in the research sample, men exhibited delayed peak bone mass attainment, lower osteocyte densities, and lower average tissue mineralization. Women achieved peak bone mass when anticipated. Relative cortical area, osteon area, bone tissue mineralization, and cortical ii porosity were the best histological indicators of menopause in women. Poorer bone health indices in males infer greater systematic marginalization under apartheid rule. Men in this sample may have been more susceptible to dietary deficiencies and substance abuse issues, leading to compromised bone mass and quality. This research demonstrates that osteoporosis risk is not just a concern of the aged, white female population in South Africa. It provides novel data on an understudied population, and underscores the importance of skeletal research collections for the study of contemporary epidemiological issues. iii Acknowledgments First, I would like to thank my doctoral supervisor, Susan Pfeiffer. She allowed me to expand my work beyond forensic research questions, and introduced me to two completely foreign places— Canada and South Africa. Throughout the dissertation process she has been firm, but also incredibly kind and supportive. I am very proud to be part of her legacy and deeply honored that she agreed to take me on as her final PhD student. I am also thankful for the wonderful network of former students and research collaborators that she has created and allowed me to join. I am indebted to my own research collaborators, Susan Pfeiffer, Marc Grynpas, Amanda Alblas, Jarred Heinrich, Jacklynn Walters, and Michelle Cameron. Without them, none of this work could have been possible. I need to acknowledge Benedict Paige, Linda Greyling, support staff in the Division of Anatomy and Health Sciences at Stellenbosch University, and the Western Cape Government Inspectorate of Anatomy for granting and facilitating my access to such an important skeletal collection. I would also like to express my tremendous gratitude and appreciation for the undergraduate students who directly contributed to this research by helping me process my samples for imaging and analysis: Virginia Pritzler, Klara Komza, Meimei Fong, Matthew Gray and Liam Wadsworth. I would like to thank my core committee, Susan Pfeiffer, Marc Grynpas and Mary Silcox, as well as the Evolutionary Anthropology faculty that have helped guide me through this process. I would be remiss if I did not explicitly acknowledge the Pfeiffer and Viola labs. More broadly, I would like to thank the administrative and custodial staff, as well as the graduate student body in the Department of Anthropology. In particular, I am grateful for Elizabeth Sawchuk, Lindi Masur, Emma Yasui, Andrew Holmes, Sarah Ranlett, Courtneay Hopper, Steven Dorland, Kathy Pitirri, Jarred Heinrich, Michelle Cameron, Thivviya Vairamuthu, Catherine Merritt, Bess Doyle, Eve Smeltzer, Walter Callaghan, Andrew Harris, and Amy Fox. The real driving force behind this project has been my friends and family. I express my deep love and appreciation for lifelong pals Maxwell Losgar, Belinda Smith, Michelle Gilbert, Michael Simmons, Colleen Cheverko, James Scheuermann, Paul Meddaugh, Maria Darr, Michala Stock, Amy Johnson, and Christian Quintanilla. The Vesley, Dunlop, Herzman, MacNeil, and Conlin clans have all provided me with endless encouragement and support. I could not be more grateful iv to belong to such an incredible family network. Above all others, I would like to thank my parents, Jane and the late Joseph Beresheim, my sister, Amanda, and my eternal rock, Cody MacNeil. v Table of Contents Acknowledgments .......................................................................................................................... iv Table of Contents ........................................................................................................................... vi List of Tables ................................................................................................................................. ix List of Figures ................................................................................................................................. x List of Appendices ....................................................................................................................... xiii List of Appendix Figures ............................................................................................................. xiv Chapter 1 Introduction .................................................................................................................... 1 1.1 Research Hypotheses .......................................................................................................... 5 1.2 Organization of the Thesis .................................................................................................. 6 1.3 Literature Cited ................................................................................................................... 6 Chapter 2 Literature Review ......................................................................................................... 10 2.1 Modeling ........................................................................................................................... 10 2.2 Remodeling and Bone Cells .............................................................................................. 10 2.3 Measures of Bone Mass and Density ................................................................................ 12 2.3.1 Back-Scattered Scanning Electron Microscopy (BSE-SEM) ............................... 13 2.4 Overview of Major Life History Events ........................................................................... 15 2.4.1 Acquisition of Peak Bone Mass ............................................................................ 15 2.4.2 Menopause and Primary Osteoporosis .................................................................. 18 2.5 Rib Bone Histomorphometry ............................................................................................ 19 2.5.1 Histomorphometric Changes in the Rib from Birth through Senescence ............. 21 2.5.2 Biomechanics of the Thorax and Body Size Considerations ................................ 22 2.6 South African Apartheid and the Social Determinants of Health ..................................... 23 2.6.1 Peak Bone Mass Attainment in South Africa ....................................................... 24 2.6.2 Osteoporosis and Fragility Fractures in South Africa ........................................... 25 2.7 Genetic Considerations ..................................................................................................... 26 2.8 Literature Cited ................................................................................................................. 27 Chapter 3 An Exploration of Body Size and Bone Mass on Cortical Bone Histomorphometry in Human Ribs.......................................................................................................................... 41 3.1 Abstract ............................................................................................................................. 41 3.2 Introduction ....................................................................................................................... 42 3.3 Materials and Methods ...................................................................................................... 44 3.3.1 Research Sample ................................................................................................... 44 3.3.2 Histological Preparation, Imaging, and Analysis ................................................. 45 vi 3.3.3 Statistical Analysis ................................................................................................ 49 3.4 Results ..............................................................................................................................