Overview Snapshot A 68-year-old woman presents to her primary care physician with lower back pain of acute onset. She denies any trauma to the spine or any radiation of pain. Her last menstrual period was when she was 51-years-old. On physical exam, she has tenderness to palpation at the level of L4-L5, as well as a loss of lumbar lordosis. A dual-energy x-ray absorptiometry (DEXA) scan reveals a T-score of -2.7. Introduction Clinical definition decreased bone mass (osteopenia) that significantly increases the patient's risk of fracture Epidemiology incidence most common types of osteoporosis are post-menopausal senile risk factors post-menopausal women being ≥ 65 years of age people of Caucasian and Asian descent lifestyle factors poor physical activity vitamin D deficiency and poor calcium intake smoking alcohol use disorder medications warfarin lithium proton pump inhibitors glucocorticoids hyperparathyroidism hyperthyroidism multiple myeloma malabsorption syndromes low body weight higher body weight associated with higher bone density Pathogenesis in young adulthood, peak bone mass is achieved and this is determined by a number of factors (e.g., genetics) after this peak bone mass is attained, there is a small decrease in bone formation with every cycle of bone remodeling senile osteoporosis osteoblasts have their biosynthetic and proliferative ability reduced with age poor physical activity mechanical force on bone stimulates bone remodeling athletes have increased bone density decreased physical activity results in bone loss weight-bearing physical activity results in increased bone mass and protects against osteoporosis decreased estrogen levels such as in menopause, decreased estrogen levels increase bone resportion and formation however, the rate of formation is less than resorption resulting in a net bone loss increased osteoclast activity is significant in areas of bone with large surface area such as the vertebral bodies, leading to vertebral compression fractures there is trabecular and cortical bone loss Prognosis generally good if detected early and appropriately managed Presentation Symptoms fractures (e.g., vertberal and hip), otherwise, patients are typically asymptomatic Physical exam may see loss in height Imaging DEXA indication all women ≥ 65 and all men ≥ 70 years of age notes T-score ≤ -2.5 Studies Labs serum calcium, phosphorus, parathyroid hormone, and alkaline phosphatase are normal Histology histologically normal; however, there is a decreased quantity of normal bone Differential Laboratory Abnormalities in Select Bone Disorders Etiology Serum Phosphate Serum Calcium Serum Alkaline Phosphatase Parathyroid Hormone Osteomalacia / rickets Decreased Decreased Increased Increased Osteoporosis Normal Normal Normal Normal Osteopetrosis Normal Normal or decreased Normal Normal Paget disease of the bone Normal Normal Increased Normal Osteitis fibrosa cystica Primaryhyperparathyroidism decreased Secondaryhyperparathyroidism increased Primaryhyperparathyroidism increased Secondaryhyperparathyroidism decreased Primary and secondary hyperparathyroidism increased Primary and secondary hyperparathyroidism increased Hypervitaminosis D Increased Increased Normal Decreased Treatment Conservative calcium and vitamin D supplementation strength training smoking cessation Medical bisphosphonates indication first-line for pharmacologic therapy in osteoporosis teriparatide indication considered first-line in patients with a very high risk of fracture Complications Fragility fractures hip distal radius vertebral body proximal humerus