Bone Loss and Osteoporosis: An Anthropological Perspective

I. Current Concepts of Bone Loss and Osteoporosis.- Concepts of Bone Remodeling: A Unified Spatial and Temporal Model with Physiologic and Pathophysiologic Implications.- 1. Introduction.- 2. The Purposes of Bone Remodeling.- 2.1. The Basic Multicellular Unit as the Instrument of Bone Remodeling.- 3. Disordered Remodeling and Age Related Bone Loss.- References.- 2. On Changing Views about Age-Related Bone Loss.- 1. Introduction.- 1.1 On the Two Paradigms.- 1.1.1 The 1960 Paradigm.- 1.1.2 The Utah Paradigm.- 2. Age-Related Bone Loss.- 3. A Proposed Synthesis.- 4. Conclusions.- References.- 3. The Role of Bone Quality on Bone Loss and Fragility.- 1. Introduction.- 2. Determination of Bone Quality.- 3. Aging Changes in the Skeleton.- 4. The Problem of Diagenesis.- 5. Changes in Bone Mineralization with Diseases and Treatments.- 6. What Determines Skeletal Fragility?.- 7. Conclusions.- References.- II. Population Approaches.- 4. Ethnic Differences in Bone Mass and Architecture.- 1. Introduction.- 1.1. Osteoporosis.- 1.2. Bone Densitometry and Assessment of Bone Architecture.- 1.3. Bone Density and Fracture Incidence.- 1.4. Use of "Race" and "Ethnicity" in Biomedical Literature on Osteoporosis.- 2. Bone Mass and Bone Density.- 2.1. Definitions of Bone Density.- 2.2. Ethnic Differences in Bone Density.- 3. Bone Quality and Bone Turnover.- 4. Factors Affecting Bone Mass and Bone Loss.- 4.1. Adjusting Bone Density for Body Size.- 4.2. Body Size and Composition, and Preservation of the Skeleton.- 4.3. Calcium Nutrition.- 4.4. Physical Activity.- 5. Bone Geometry.- 5.1. Hip Axis Length.- 5.2. Cross-Sectional Geometry.- 6. Fracture Incidence.- 7. Summary.- References.- 5. Bone Loss, Fracture Histories, and Body Composition Characteristics of Older Males.- 1. Background.- 1.1. Definition of Terms.- 1.2. Bone Loss in Other Primates.- 1.3. Population Differences.- 2. Risk Factors.- 2.1. Factors Influencing Bone Turnover.- 2.2. Peak Bone Mass.- 2.3. Endocrinological Factors.- 2.4. Vitamin D and Vitamin D Receptors.- 2.5. Body Composition and Mechanical Factors.- 3. The Sun City/Tucson Longitudinal Study.- 3.1. Objectives.- 3.2. Subjects.- 3.3. Methods.- 3.4. Results.- 4. Discussion.- 4.1. Observed Bone Loss.- 4.2. Changes in Body Composition.- 4.3. Nutrition, Bone Density, and Prostate Cancer.- 5. Summary and Conclusions.- References.- 6. The Histomorphometry of the Subadult Rib: Age-Associated Changes in Bone Mass and the Creation of Peak Bone Mass.- 1. Introduction.- 1.1. Intracortical Bone Remodeling in the Subadult Rib.- 1.2. Peak Bone Mass and Age-Associated Bone Loss.- 1.3. Factors Determining Peak Bone Mass.- 2. A Study of Subadult Rib Histomorphometry.- 2.1. Cross-Sectional Areas and Bone Mass.- 2.1. Intracortical Remodeling: Osteon Population Density and Osteon Size.- 3. Summary and Conclusions.- References.- III. Evolutionary Perspectives.- 7. An Evolutionary and Biocultural Approach to Understanding the Effects of Reproductive Factors on the Female Skeleton.- 1. Introduction.- 2. Pregnancy.- 3. Parity.- 4. Lactation.- 5. Animal Models.- 6. Evolutionary and Historical Evidence.- 7. Discussion.- 8. Conclusions.- References.- 8. Functional Adaptation and Fragility of the Skeleton.- 1. Introduction.- 2. Mechanisms of Functional Adaptation.- 2.1. Effector Cells.- 2.2. Sensor Cells.- 2.3. Strain and the Mechanostat.- 2.4. The Two Poles of Adaptation.- 2.4.1. Disuse: Subnormal Loading.- 2.4.2. Overuse: Supernormal Loading.- 3. Skeletal Maintenance.- 3.1. Fatigue Damage Activates Remodeling.- 3.2. Remodeling Reduces Skeletal Weight.- 3.3. Responsive vs. Permissive Remodeling.- 3.4. The Volume Effect on Strength and Fatigue Life.- 3.5. Somatic vs. Evolutionary Adaptation.- 4. Skeletal Fragility.- 4.1. The Mechanostat and Sexual Dimorphism.- 4.2. Mechanical Priorities in Male and Female Bones.- 4.3. Estrogen and the Mechanostat Set Point.- 4.4. Menopause, the Set Point, and Postmenopausal Fragility.- 5. Summary.- Acknowledgments.- Refer