1. Osteoporosis Educational Series, Lecture 2of 3: Understanding Bone to Understand Osteoporosis: Pathogenesis and Risk Factors Nahid Rianon, M.D., Dr.P.H. The University of Texas Health Science Center at Houston

2. Goal and Objectives GOAL: The goal of this presentation is to describe detail mechanism of bone loss and risk of fractures LEARNING OBJECTIVES: At the end of this presentation, attendees will be able to  Explain normal and abnormal state of bone metabolism  Define bone remodeling  Identify risk factors for bone loss  Calculate risk of facture

3. What percent of adult human bone is made of minerals? a)20% b)65% c)75% d)90% Pre Quiz Question 1 of 5

4. Which of the following factors stimulate osteoblasts? (Choose one) a)Glucocorticoids and Estrogen b)Thyroxine and Androgen c)Estrogen and Growth Hormone d)Vitamin D and Thyroxine Pre Quiz Question 2 of 5

5. Which one of the following statements best fits the pathological state of osteoporosis due to age related bone loss? a)Bone formation and resorption are in balance b)Both formation and resorption slows down at the same rate c)Both formation and resorption increases at the same rate d)Bone resorption is greater than bone formation Pre Quiz Question 3 of 5

6. Which of the following diseases is not considered a risk for developing secondary osteoporosis (when remains untreated) for FRAX calculation tool? a)Diabetes Mellitus type II b)Hypothyroidism c)Diabetes Mellitus type I d)Osteogenesis Imperfecta in adults Pre Quiz Question 4 of 5

7. Pre Quiz Question 5 of 5 In humans, trabecular bone volume is larger than cortical bone volume? a) True b) False

8. Function  Mechanical  Weight bearing  Protection for soft organs  Attachment for muscles  Mineral reservoir  Calcium  Phosphorus Why Do We Need Strong Bones:

9. Overall  Organic Matrix  10% of adult bone  Primarily protein collagen -provides flexibility  Mineral Component  65% of adult bone  Hydroxyapatite - insoluble salts of calcium (99%) & phosphorus (85%)  Very little Mg, Na & HCO 3  Water  25% of adult bone Bone Structure

10. Cellular  Osteoblasts  Critical to bone formation  Osteoclasts  Reabsorb bone  Osteocytes  Exact role is still under investigation Bone Structure Osteoblasts Osteoclasts Osteocytes

11. Types of boneForces on bone Trabecular  20% of skeletal mass  Greater surface area than cortical  Provides supporting strength to the ends of weight-bearing bones Cortical  80% of skeletal mass  Solid outside shaft of long bones Compressive stress  From body weight pushing the bone down Tensile stresses  From muscles, pulling the bone apart Bone Structure

12. Trabecular and Cortical Bones Trabecular bone Cortical bone Femur with loss of mineral and microstructure Healthy femur Tensile Comprehensive Mineral loss

13. Physiology- Normal State Bone Marrow Progenitors Osteoblast PrecursorOsteoclast Precursor Glucocorticoids Estrogen Calcitonin Estrogen Androgens GH/IGF-1 Thyroxine Vitamin A Osteoblast New Bone Formation Bone Resorption Osteoclast Osteocyte 1,25 OHD PTH + _ _ *Find out if this is 1,25 (OH)2D +

14. Pathogenesis Of Osteoporosis - Bone Remodeling Normal Bone Remodeling Sequence Resorption = Formation No change in bone mass LEGEND: LC = Lining Cells CL = Cement Line OS = Osteoid BRU = Bone Remodeling Unit Osteoclast Precursor Osteoclast Osteoblast Precursors Osteoblast Mononuclear Cells

15. High bone turnover state Unbalanced remodeling Osteoporosis Basic Pathology Normal Bone Structure Osteoporotic Bone Structure

16. Resorption > Formation Net bone loss Unbalanced Remodeling & Osteoporosis Influencers: Inadequate calcium or vitamin D Menopause Aging Medications or diseases

17.  Increasing age  Female gender  Early menopause  Low body weight  Previous fracture  Family history  Low calcium intake  Low vitamin D  Alcohol  Smoking  Physical inactivity  High caffeine intake  Drug use- steroid  White or Asian race Osteoporosis Risk Factors

18. FRAX Calculator

19.  Age (40-90), gender, height & weight  Previous fracture  Hip fracture in parents  Current smoking  Alcohol  Glucocorticoids (oral) ≥ 3 months @ dose 5mg daily or more  or equivalent doses of other glucocorticoids  Rheumatoid arthritis  Secondary osteoporosis  DM-I, OI in adults,  Untreated hyper or hypothyroidism,  Premature menopause (< 45 yrs),  Chronic malnutrition or malabsorption &  Chronic liver disease  Bone mineral density (BMD) FRAX Risk Factors

20. Post Quiz Question 1 of 5 What percent of adult human bone is made of minerals? a)20% b)65% c)75% d)90%

21. Post Quiz Question 2 of 5 Which of the following factors stimulate osteoblasts? (Choose one) a)Glucocorticoids and Estrogen b)Thyroxine and Androgen c)Estrogen and Growth Hormone d)Vitamin D and Thyroxine

22. Post Quiz Question 3 of 5 Which one of the following statements best fits the pathological state of osteoporosis due to age related bone loss? a)Bone formation and resorption are in balance b)Both formation and resorption slows down at the same rate c)Both formation and resorption increases at the same rate d)Bone resorption is greater than bone formation

23. Post Quiz Question 4 of 5 Which of the following diseases is not considered a risk for developing secondary osteoporosis (when remains untreated) for FRAX calculation tool? a)Diabetes Mellitus type II b)Hypothyroidism c)Diabetes Mellitus type I d)Osteogenesis Imperfecta in adults

24. In humans, trabecular bone volume is larger than cortical bone volume? a) True b) False Post Quiz Question 5 of 5

25. Questions? Thank You

26. Reference American Society for Bone and Mineral Research http:www.asbmr.org WHO Fracture Risk Assessment Tool (FRAX) http://www.sheffield.ac.uk/FRAX/tool.jsp

27. Brought to you by TEXAS. The Training Excellence in Aging Studies (TEXAS) program promotes geriatric training from medical school through the practicing physician level. This project is funded by the Donald W. Reynolds Foundation to the division of Geriatrics and Palliative Medicine within the department of Internal Medicine at The University of Texas Health Science Center at Houston (UTHealth). TEXAS would also like to recognize the following for contributions: Houston Geriatric Education Center Harris County Hospital District Memorial Hermann Foundation Huffington Lecture Series The TEXAS Advisory Board Othello "Bud" and Newlyn Hare UTHealth Medical School Office of the Dean UTHealth School of Nursing UTHealth Consortium on Aging UTHealth Multimedia Scriptorium (www.uth.tmc.edu/scriptorium) Ben Earwicker for the use if his photos (www.garrisonphoto.org/sxc) Photographs use for the cover are allowed by the morgueFile free photo agreement and the Royalty Free usage agreement at Stock.xchng. They appear on the cover in this order: Wallyir at morguefile.com/archive/display/221205 Mokra at www.sxc.hu/photo/572286 Clarita at morguefile.com/archive/display/33743 Copyrighted images cannot be used in whole or part without the explicit permission of the owner.