NUR 317 Exam 5 - Osteoporosis

Osteoporosis

• Chronic, progressive metabolic bone disease marked by

  • Low bone mass

  • Deterioration of bone tissue

• Leads to increased bone fragility

What is the precursor to osteoporosis?

Osteopenia

Bone remodeling

• Remodeling

  • Osteoblasts – Continuously break down bone

  • Osteoclasts – Form bone

• Rate of bone deposition and resorption are normally equal

• In osteoporosis, bone resorption exceeds bone deposition

Why is osteoporosis known as the “silent thief”?

It has no noticeable symptoms in its early stages and can lead to fractures that increase mortality risk

Why is osteoporosis more common in women?

• Lower intake of calcium

• Less bone mass

• Bone resorption begins earlier and becomes more rapid at menopause

• Pregnancy and breastfeeding

• Longevity

Osteoporosis screening guidelines

• Initial bone density test in women over age 65

  • Repeat in 15 years if normal

  • Repeat sooner if patient is high risk

• Currently no evidence of benefit for screening in men

Osteoporosis risk factors

• Advancing age (>65 yr)

• Female gender

• Low body weight

• White or Asian

• Current cigarette smoking

• Prior fracture

• Sedentary lifestyle

• Estrogen deficiency

• Family history

• Diet low in calcium/vitamin D deficiency

• Excessive use of alcohol (>2 drinks/day)

• Low testosterone in men

• Specific diseases

• Certain drugs

Osteoporosis etiology and pathophysiology

• Peak bone mass (by age 20) determined by heredity, nutrition, exercise, and hormone function

• Bone loss after age 35-40 is inevitable, rate of loss is variable

• Rapid bone loss for women at menopause

Osteoporosis preventative factors

• Regular weight-bearing exercises

• Diet and supplements

  • Fluoride

  • Calcium

  • Vitamin D

• Healthy lifestyle

  • Avoid smoking and heavy drinking

Osteoporosis clinical manifestations

• Occurs most commonly in spine, hips, and wrists

• Common manifestations

  • Stooped posture

  • Joint pain

  • Bone pain and tenderness

  • Back pain (early manifestation)

  • Bone fractures (early manifestation)

• Gradual loss of height

• Kyphosis

  • “Dowager’s Hump”

Osteoporosis diagnostic studies

• History and physical exam

• X-ray and lab studies not diagnostic

• Bone mineral density (BMD)

  • Quantitative ultrasound (QUS)

    • Heel, kneecap, shin

  • Dual-energy x-ray absorptiometry (DEXA)

    • Spine, hip (entire skeleton)

What is the gold standard osteoporosis test?

Dual-energy x-ray absorptiometry (DEXA)

Osteoporosis diagnostic studies T and Z-scores

• T-scores

  • T-score between +1 and -1 = normal bone density

  • T-score between -1 and -2.5 = osteopenia

  • T-score -2.5 or lower = osteoporosis

• Z-score compares with someone own age and ethnicity

Fracture risk assessment (FRAX)

Osteoporosis interprofessional care

• Focus on

  • Proper nutrition

  • Exercise

  • Prevent fractures and breaks

  • Calcium and Vit D supplements

  • Drug therapy

  • Stop smoking

  • Decrease alcohol intake

• Postmenopausal treatment

  • Treat if:

    • T-score less than -2.5

    • T-score between -1 and -2.5 if additional risk factors exist

    • Prior history of hip or vertebral fractures

Osteoporosis calcium intake

1000 mg/day for:

• Women ages 19-50 years

• Men ages 19-70 years

1200 mg/day for

• Women 51 years or older

• Men 71 years or older

Osteoporosis supplemental calcium therapy

• Take in divided doses

• Calcium carbonate

  • 40% elemental calcium

  • Take with food, vitamin D

• Calcium citrate

  • 20% elemental calcium

  • Less dependent on stomach acid

• No – calcium lactate or calcium gluconate

  • Not enough elemental calcium

Osteoporosis vitamin D

• Vitamin D necessary for calcium absorption/function; bone formation

• Sunlight for 20 minutes/day is adequate

• Supplemental (800-1000 IU/day)

  • Postmenopausal

  • Older men

  • Homebound/long-term care

  • Minimal sun exposure

Osteoporosis drug therapy

• Biphosphonates

• Monoclonal antibodies

• Recombinant parathyroid hormone

Biphosphonates

• Inhibit bone resorption

• Side effects: anorexia, weight loss, gastritis

• Proper administration

  • Take with full glass of water

  • Take 30 minutes before food or other meds

  • Remain upright for at least 30 min

• Long term use – need to take for several years

Alendronate (Fosamax)

• Biphosphonate

• Usually take once per week

• Can also take daily

Risedronate (Actonel)

• Biphosphonate

• Can take daily, weekly, or monthly

Zoledronic acid (Reclast)

• Biphosphonate

• Yearly or every other year IV infusion

Monocloncal antibodies

• Denosumab (Prolia, Xgeva)

  • For postmenopausal women

  • Subcutaneous injection every 6 months

• Need calcium and Vitamin D supplements

Teriparatide (Forteo)

• Recombinant parathyroid hormone

• Stimulates new bone formation

• Daily subcu injection from preloaded pen

• Must monitor parathyroid hormone levels

• Use up to 2 years

Osteomalacia

• Loss of vitamin D – may be rare in US

  • Loss of calcium

  • Bone softening/weakening

• Same as rickets in children

Osteomalacia etiology

• Vitamin D deficiency

• Lack of exposure to sunlight

• GI malabsorption

• Chronic diarrhea

• Pregnancy

• Diseases: chronic kidney, liver, small bowel

• Bariatric surgery

• Medications (long term)

  • Phenytoin

  • Cholestyramine

  • Maalox

Osteomalacia clinical manifestations

• Bone pain

• Weakness

• Difficult rising from a chair

• Difficulty walking

• Weight loss

• Progressive kyphosis

• Delayed bone healing after a fracture

Osteomalacia laboratory and imaging diagnosis

• Laboratory

  • Decreased serum

  • Elevated serum alkaline phosphatase

• X-Ray

  • Bone demineralization

  • Looser’s Transformation Zones (ribbons of decalcified bone)

Osteomalacia treatment

• Correct Vitamin D deficiency

  • Vitamin D3 (cholecalciferol)

  • Vitamin D2 (ergocalciferol)

• Supplements – calcium and phosphorous

• Dietary changes

• Sunlight therapy

• Weight-bearing exercises