Osteoporosis

Overview

• Chronic dz of cellular regulation in which bone loss = significant decrease in density & possible fractures

• “silent dz”

• Vocab:

  • Osteopenia: bone mineral density below normal values (bone loss), but not low enough to be considered osteoporosis

  • Osteomalacia: bone loss r/t lack of Vitamin D that leads to bone softening

Patho

• bone is a living tissue constantly changing

  • osteoblasts & osteoclasts

• when osteoclastic activity > osteoblastic activity = decreased bone mineral density (BMD)

  • osteoblastic: bone building

  • osteoclastic: bone resorption

• BMD amount of mineral that determines bone strength

  • peaks 25-30 yrs

  • after the peak, bone-building activity outpaced by osteoclastic activity

Primary Osteoporosis

• more common

• post menopausal women & men > 50 yrs

• complex causes

Secondary Osteoporosis

• results from other medical conditions

  • hyperparathyroidism

  • long-term drug therapy (corticosteroids)

  • prolonged decreased mobility

• regional (localized) osteoporosis

  • limb immobilized for > 8-12 wks

Primary Osteoporosis: Nonmodifiable Risks

• Age > 50 yrs

• menopause or hx of total hysterectomy

• parental hx, especially mother

• white or asian ethnicity

• history of eating disorders

• rheumatoid arthritis

• history of any fracture after age > 50 yrs

Primary Osteoporosis: Modifiable Risk Factors

• low body weight, thin build

• poor nutrition/vitamin deficiency

• estrogen or androgen deficiency

• smoking

• high alcohol intake

• drug therapy

• lack of physical exercise or prolonged decreased mobility

Nutrition & Sunlight

• excessive caffeine in the diet can cause calcium loss in the urine

• diet lacking calcium & Vitamin D stimulates the parathyroid gland → more release of calcium from bones

• activated Vit D is needed for Ca uptake

• malabsorption of nutrients in the small intestine contributes to low serum Ca levels

• exposure to sunlight synthesizes Vit D in the skin

• institutionalized or homebound pts who are not exposed to sunlight may be at a higher risk bc they do not receive adequate Vit D for the metabolism of Ca

Assessment

• Health History: older pts may state they have gotten shorter, as much as 2-3 inches

• Kyphosis: outward curvature of the thoracic spine causing a “humpback”

• Back Pain: exacerbated by activity

  • compression vertebral fractures

• S/E of mobility restriction and/or spinal deformity

  • constipation

  • abdominal distension

  • reflux esophagitis

Diagnostics

• based on T-score

  • the # of standard deviations above or below the avg BMD for young, healthy adults (T-score of 0)

  • Osteopenia: 1-2.5

  • Osteoporosis: <2.5

• Labs: serum calcium and Vitamin D

• Imaging Assessment: X-rays of spine & long bones

  • DXA: dual x-ray absorptiometry

    • test that gives us T-scores

  • QCT: qualitative computed tomography

TX

• Nutrition Therapy: calcium rich diet

  • dairy products, soy/rice prod fortified w calcium/Vit D

  • dark green leafy veg

• avoid excessive alcohol/caffein consumption

• Lifestyle Changes:

  • walking for 30 min 3-5x/week

  • weight bearing exercises/muscle strengthening

  • avoid activities that cause jarring of the body

Drug Therapy

• bisphosphonates

• calcium

• estrogen agonists

• RANKL inhibitors

Prevention & Pt Education

• vitamin D

• stop smoking

• lose weight

• avoid alcohol

• limited carbonated beverages

• exercise and weight-bearing exercises

• continuous to follow up w/ DXA screenings as recommended to assess ongoing bone health