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 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
QUESTIONS 1 of 4 1 2 3 4 Previous Next Lab Values Blood Hematologic Cerebrospinal Sweat, Urine, and BMI Blood, Plasma, Serum Reference Range ALT 8-20 U/L Amylase, serum 25-125 U/L AST 8-20 U/L Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL Calcium, serum (Ca2+) 8.4-10.2 mg/dL Cholesterol, serum Rec: < 200 mg/dL Cortisol, serum 0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h Creatine kinase, serum Male: 25-90 U/LFemale: 10-70 U/L Creatinine, serum 0.6-1.2 mg/dL Electrolytes, serum Sodium (Na+) 136-145 mEq/L Chloride (Cl-) 95-105 mEq/L Potassium (K+) 3.5-5.0 mEq/L Bicarbonate (HCO3-) 22-28 mEq/L Magnesium (Mg2+) 1.5-2.0 mEq/L Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL Ferritin, serum Male: 15-200 ng/mLFemale: 12-150 ng/mL Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250 pH 7.35-7.45 PCO2 33-45 mmHg PO2 75-105 mmHg Glucose, serum Fasting: 70-110 mg/dL2-h postprandial:<120 mg/dL Growth hormone - arginine stimulation Fasting: <5 ng/mLProvocative stimuli: > 7ng/mL Immunoglobulins, serum IgA 76-390 mg/dL IgE 0-380 IU/mL IgG 650-1500 mg/dL IgM 40-345 mg/dL Iron 50-170 μg/dL Lactate dehydrogenase, serum 45-90 U/L Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL Osmolality, serum 275-295 mOsmol/kd H2O Parathyroid hormone, serume, N-terminal 230-630 pg/mL Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L Phosphorus (inorganic), serum 3.0-4.5 mg/dL Prolactin, serum (hPRL) < 20 ng/mL Proteins, serum Total (recumbent) 6.0-7.8 g/dL Albumin 3.5-5.5 g/dL Globulin 2.3-3.5 g/dL Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h Thyroxine (T4), serum 5-12 μg/dL Triglycerides, serum 35-160 mg/dL Triiodothyronine (T3), serum (RIA) 115-190 ng/dL Triiodothyronine (T3) resin uptake 25%-35% Urea nitrogen, serum 7-18 mg/dL Uric acid, serum 3.0-8.2 mg/dL Hematologic Reference Range Bleeding time 2-7 minutes Erythrocyte count Male: 4.3-5.9 million/mm3Female: 3.5-5.5 million mm3 Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/hFemale: 0-20 mm/h Hematocrit Male: 41%-53%Female: 36%-46% Hemoglobin A1c ≤ 6 % Hemoglobin, blood Male: 13.5-17.5 g/dLFemale: 12.0-16.0 g/dL Hemoglobin, plasma 1-4 mg/dL Leukocyte count and differential Leukocyte count 4,500-11,000/mm3 Segmented neutrophils 54%-62% Bands 3%-5% Eosinophils 1%-3% Basophils 0%-0.75% Lymphocytes 25%-33% Monocytes 3%-7% Mean corpuscular hemoglobin 25.4-34.6 pg/cell Mean corpuscular hemoglobin concentration 31%-36% Hb/cell Mean corpuscular volume 80-100 μm3 Partial thromboplastin time (activated) 25-40 seconds Platelet count 150,000-400,000/mm3 Prothrombin time 11-15 seconds Reticulocyte count 0.5%-1.5% of red cells Thrombin time < 2 seconds deviation from control Volume Plasma Male: 25-43 mL/kgFemale: 28-45 mL/kg Red cell Male: 20-36 mL/kgFemale: 19-31 mL/kg Cerebrospinal Fluid Reference Range Cell count 0-5/mm3 Chloride 118-132 mEq/L Gamma globulin 3%-12% total proteins Glucose 40-70 mg/dL Pressure 70-180 mm H2O Proteins, total < 40 mg/dL Sweat Reference Range Chloride 0-35 mmol/L Urine Calcium 100-300 mg/24 h Chloride Varies with intake Creatinine clearance Male: 97-137 mL/minFemale: 88-128 mL/min Estriol, total (in pregnancy) 30 wks 6-18 mg/24 h 35 wks 9-28 mg/24 h 40 wks 13-42 mg/24 h 17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 hFemale: 2.0-8.0 mg/24 h 17-Ketosteroids, total Male: 8-20 mg/24 hFemale: 6-15 mg/24 h Osmolality 50-1400 mOsmol/kg H2O Oxalate 8-40 μg/mL Potassium Varies with diet Proteins, total < 150 mg/24 h Sodium Varies with diet Uric acid Varies with diet Body Mass Index (BMI) Adult: 19-25 kg/m2 Calculator ( ) xy AC 7 8 9 ÷ 4 5 6 × 1 2 3 - 0 . = + Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK You have 100% on this question. Just skip this one for now. Take This Question Anyway (M1.MK.15.4666) A 72-year-old woman comes to you complaining of severe back pain. She reports that she slipped and fell in her shower at home. She also had a wrist fracture 2 years ago and an ankle fracture last year. The patient reports that she has been taking an over-the-counter vitamin D supplement. She has not had any diffuse bone pain. Figure A shows a radiograph of her spine. Labs values for parathyroid hormone, calcium, phosphate, and alkaline phosphate are normal. Which of the following is the most likely underlying abnormality? Review Topic | Tested Concept QID: 107095 FIGURES: A Type & Select Correct Answer 1 Subperiosteal bone resorption 33% (11/33) 2 Vitamin D deficiency 0% (0/33) 3 Excessive unmineralized osteoid 21% (7/33) 4 Trabecular thinning 39% (13/33) 5 Hypocalcemia 3% (1/33) L 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4