Metabolic Bone Disease - Clin Med PDF

Metabolic Bone Disease ASHLEY NORDAN, MHPE, MSCR, MPAP, PA-C CAMPBELL PA PROGRAM SPRING 2024 Objectives  Define metabolic bone disease.  Review the physiology of bone formation and metabolism.  Compare and contrast the pathophysiology, epidemiology, risk factors, clinical presentation and diagnos...

Metabolic Bone Disease ASHLEY NORDAN, MHPE, MSCR, MPAP, PA-C CAMPBELL PA PROGRAM SPRING 2024 Objectives  Define metabolic bone disease.  Review the physiology of bone formation and metabolism.  Compare and contrast the pathophysiology, epidemiology, risk factors, clinical presentation and diagnosis of the following metabolic bone disorders:   Osteopenia  Osteoporosis  Rickets & Osteomalacia  Osteitis deformans (Paget disease) Discuss the classification of bone mineral density using dual-energy x-ray absorptiometry (DXA)  Explain the use of the Fracture Risk Assessment Tool (FRAX) including interpretation of FRAX scores.  Discuss current USPSTF screening recommendations for osteoporosis.  Discuss the potential complications associated with metabolic bone disorders including those associated with falls.  Counsel a patient on risk stratification and lifestyle modifications to aid in the treatment and prevention of osteoporosis, osteopenia, and associated complications. Metabolic Bone Disease  Umbrella term for group of conditions causing generalized changes in bone density that affects bone integrity. Decreased Bone Density Osteoporosis Osteopenia Rickets Osteomalacia Increased Bone Density Paget Disease Osteopetrosis Physiology Review Osteitis Deformans (Paget Disease)   Excessive bone resorption and haphazard bone growth resulting in weak, misshapen bones.  Lytic Phase  Aggressive demineralization  Mixed Phase  Rapid proliferation of new bone  Sclerotic Phase  Bone formation exceeds resorption Epidemiology:  Common in aging bones (2.3-9%)  Onset typically after age 55  Slight male predominance  Increased risk for primary bone tumors Osteitis Deformans (Paget Disease)  Clinical Presentation:  Most often asymptomatic, but may present with pain and visible bone deformity  Predilection for skull, T & L spines, pelvis and long bones on lower extremities    Fractures and nerve compression Labs:  Elevated alkaline phosphatase  Normal serum calcium and phosphorous Imaging:  Mix of lytic lesions with bone thickening and enlargement Osteomalacia & Rickets   Softening of the bones caused by defective mineralization  Adults   Kids  “Rickets” Epidemiology:   “Osteomalacia” Rare in developed countries Etiology:  Most commonly caused by deficiencies in Vitamin D, Calcium and/or Phosphorus Osteomalacia & Rickets Deficiency Common Causes Vitamin D -Inadequate sun exposure -Inadequate dietary intake/Malnutrition -Obesity -Pregnancy -Certain Drugs – Phenytoin, Phenobarbital, Carbamazepine Calcium -Inadequate dietary intake -Renal failure (increased excretion) -Hyperparathyroidism -Malabsorption (ie. celiac) Phosphorus -Genetic disorders -Tumor-induced (mesenchymal tumors) -Intestinal Malabsorption -Alcoholism Osteomalacia (Adults)  Clinical Presentation:  Bone Pain  Bone tenderness  Fracture  Gait disturbances  Muscle spasms, cramps and other signs of hypocalcemia  May present as osteopenia on imaging Rickets (Kids)  Clinical Presentation:  Delayed closure of fontanelles  Parietal and frontal bossing  Soft skull bones  Enlargement of costochondral junction (Rachitic rosary)  Harrison sulcus  Bowing of distal radius and ulna, femur and tibia Osteoporosis & Osteopenia   Low bone mass, microarchitectural disruption, and skeletal fragility causing…  Decreased bone strength  Increased risk of fracture Epidemiology:  Most common in post-menopausal Caucasian women Osteoporosis & Osteopenia  Risk Factors:  Lifestyle  Smoking (shocking), EtOH use disorder  Drugs   Hormones  Testosterone def (men), estrogen def (women), Hyperparathyroidism, Cushing's, Hyperthyroidism  Nutritional  Chronic PPI and steroid use; Depo Provera Vitamin D def, Calcium def Osteoporosis & Osteopenia   Clinical Presentation:  No “Classic symptoms”   Incidental finding on imaging or identified on screening Diagnosis:  Dual-Energy X-ray Absorptiometry (DEXA or DXA) scan    asymptomatic until fracture Used to estimate bone mineral density using both low and high-energy photons Osteoporosis can be diagnosed clinically in the presence of a fragility fracture Complications:  Osteoporotic fractures DXA Scan   Results are reported as “T scores” and/or ”Z scores”  T score  BMD of the pt compared to a young adult of same ethnicity and sex  Z score  BMD of the pt compared to an age-matched reference population of the same ethnicity and sex Diagnostic Criteria:  Osteoporosis - T score ≥ -2.5  Osteopenia – T score -1.0 to -2.4 DXA Images – Lumbar Spine Normal Abnormal DXA Images – Proximal Femur Normal Abnormal DXA Images - Forearm Normal Osteoporosis Screening - USPSTF https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/osteoporosisscreening#fullrecommendationstart Fracture Risk Assessment  Several different clinical assessment tools for osteoporotic fracture risk…  Fracture Risk Assessment Tool (FRAX)**  Simple Calculated Osteoporosis Risk Estimation (SCORE)  Osteoporosis Index of Risk (OSIRIS)  Osteoporosis Risk Assessment Instrument (ORAI)  Osteoporosis Self-Assessment Tool (OST) FRAX Score  University of Sheffield 2008    https://www.sheffield.ac.uk/FRAX/ Estimates 10-year risk of hip and major osteoporotic fracture in patients 40-90 years old using clinical risk factors +/- DXA results  Personal and family hx of fracture  Smoking and alcohol use  Steroid use  Personal hx of RA or secondary osteoporosis Screening threshold  9.3% Case: Demi Moore  DOB: 11/11/62  Current everyday smoker  Drinks 1 glasses of wine a day  No personal or fam hx of fracture  Ht. 5’5 Wt.121lbs  What is her 10-year fracture risk?  When should she have a DXA scan? Osteoporotic Fractures    Epidemiology:  1.5 million fractures annually  More commonly associated with osteopenia than osteoporosis Presentation:  Vertebral fractures are most common  Other common locations  hip, wrist, metatarsals and ribs Majors implications of fractures…  Increased risk of mortality for 10 years following fracture  1-year mortality rate as high as 58% in pts 65+ Osteoporotic Fractures Prevention of Osteoporotic Fractures   Prevention of osteoporosis:  Modifiable risk factor avoidance  holidays) tobacco, EtOH, medications (drug  Regular weight bearing exercise  Healthy diet  Calcium and Vitamin D supplementation Prevention of injury:  Most osteoporotic fractures are a result of falls Falls in the Elderly  Approximately 30% of people over 65 and 50% of people over 80 will fall each year  50% falls result in some type of injury  Main risk factor for falls   Etiology: problems with mobility  Intrinsic factors  chronic disease (foot disorders, cognitive impairment, decreases in vision)  Challenges to postural control   Mediating factors   positional change, orthostatic hypotension risk taking, situational hazards, medication side effects Rugs, stairs, furniture, etc. Fall Prevention   Screening:  Medicare wellness visits  Fall risk assessment tools Physical Exam:  ”Up and Go” test  Performance-Oriented Mobility Assessment (POMA)  Chair stand  Berg balance test PerformanceOriented Mobility Assessment of Balance Fall Prevention  Multifactorial interventions  Exercise → gait training, balance & strengthening exercises  Targeted physical therapy  Manage postural hypotension  Manage foot problems and ensure proper footwear  Treat vision impairment  Home and environmental safety  Install handrails, take away rugs, etc. References  Fitzgerald PA. Metabolic Bone Disease. In: Papadakis MA, McPhee SJ, Rabow MW, McQuaid KR. eds. Current Medical Diagnosis & Treatment 2022. McGraw Hill; 2022. Accessed January 05, 2022. https://accessmedicine-mhmedical-com.proxy.campbell.edu/content.aspx? bookid=3081&sectionid=258975311  Fenn, P. Fats, Bones & Tumors. 2020.  Rosen HL, et al. Clinical manifestations, diagnosis, and evaluation of osteoporosis in postmenopausal women. UpToDate. 2021. Accessed Febuary 14, 2022. https://www-uptodatecom.proxy.campbell.edu/contents/clinical-manifestations-diagnosis-and-evaluation-ofosteoporosis-in-postmenopausal-women? search=osteoporosis&source=search_result&selectedTitle=3~150&usage_type=default&display_ran k=2  Whitaker, S. Geriatric Medicine. (2021)  Carpenter, T. Overview of Rickets in Children. UpToDate. 2021. Accessed February 21, 2022. https:// www-uptodate-com.proxy.campbell.edu/contents/overview-of-rickets-in-children? search=Metabolic%20bone%20diseases&source=search_result&selectedTitle=4~150&usage_type= default&display_rank=4#H3