Skip to content

Osteoporosis and Osteopenia

BASICS

Description

  • Osteoporosis: Metabolic bone disease with low bone mass and deteriorated microarchitecture, causing increased fragility and fracture risk.
  • Osteopenia: Milder reduction in bone mass (precursor to osteoporosis).

EPIDEMIOLOGY

  • 10.2 million Americans have osteoporosis; 43.3 million have low bone mass.
  • Women >50: 19.6% osteoporosis, 51.5% osteopenia
  • Men >50: 4.4% osteoporosis, 33.5% osteopenia

ETIOLOGY & PATHOPHYSIOLOGY

  • Imbalance between bone resorption and formation → net loss of bone density.
  • Genetics: Familial predisposition; more common in Caucasians & Asians.
  • Common causes: Malabsorption (IBD, celiac, gastrectomy), hypoestrogenism (menopause, hypogonadism), endocrinopathies (hyperparathyroidism, hyperthyroidism, diabetes, hypercortisolism), chronic diseases (renal failure, myeloma), medications (chronic steroids, chemo, aromatase inhibitors, anti-epileptics, heparin, SSRIs, PPIs, excessive thyroid hormone).

COMMONLY ASSOCIATED CONDITIONS

  • Malabsorption syndromes, hypoestrogenism, endocrinopathies, hematologic disorders, chronic renal disease
  • Medications as above

DIAGNOSIS

History

  • Assess modifiable (smoking, alcohol, inactivity, poor nutrition) and nonmodifiable (age, sex, race, family hx) risk factors.
  • Prior fragility fracture
  • Use FRAX tool for risk stratification: https://www.shef.ac.uk/FRAX/

Physical Exam

  • Kyphosis (“Dowager’s hump”), poor balance, height loss (>4 cm historical, >2 cm prospective)

Differential Diagnosis

  • Primary hyperparathyroidism, multiple myeloma, Paget's disease

Diagnostic Tests

  • DEXA (dual energy x-ray absorptiometry): Gold standard for bone mineral density (BMD)
    • T-score:
      • +1 to -1: Normal
      • -1 to -2.5: Osteopenia
      • ≤ -2.5: Osteoporosis
    • Z-score: Age/sex-matched, < -2 suggests secondary causes
  • Trabecular bone score (TBS): risk stratification with osteopenic BMD
  • Labs: Chemistry (calcium, phosphorus, ALP), CBC, 25-OH vitamin D
  • Radiographs: Poor sensitivity; consider if vertebral fracture suspected

Further evaluation if indicated:

  • 24h urine Ca, creatinine, cortisol; SPEP/UPEP; FSH/LH, prolactin; magnesium, PTH, TSH, celiac serology; ESR, RF, iron studies, tryptase, homocysteine; consider marrow biopsy

TREATMENT

Lifestyle

  • Weight-bearing/resistance exercise
  • Balanced diet (calcium, vitamin D)
  • Avoid smoking, limit alcohol

Pharmacologic Indications

  • T-score ≤ -2.5
  • Prior fragility fracture
  • Osteopenia with high fracture risk (FRAX: ≥3% hip, ≥20% major osteoporotic fracture in 10 years)
  • Postmenopausal women/men >50 with qualifying fracture/BMD

Calcium & Vitamin D

  • Calcium: 1,200 mg (diet + supplement)
  • Vitamin D: ≥800 IU/day

First-Line: Bisphosphonates

  • Alendronate: 10 mg PO daily or 70 mg weekly
  • Risedronate: 5 mg PO daily, 35 mg weekly, or 150 mg monthly
  • Zoledronic acid: 5 mg IV yearly or q18 months
  • Avoid in: Esophageal issues, inability to sit upright, hypocalcemia, severe renal impairment (CrCl ≤30–35)

Side Effects

  • GI (esophagitis/gastritis), osteonecrosis of jaw (mainly IV/high dose), atypical femur fracture (if >5 yrs use)

Second-Line / Special Circumstances

  • Denosumab: 60 mg SC every 6 months (preferred in renal impairment; monitor for rebound after discontinuation)
  • Romosozumab: 210 mg monthly ×12 months (follow with bisphosphonate; ↑ CV risk)
  • PTH analogs: Teriparatide 20 µg SC daily, Abaloparatide 80 µg SC daily (max 2 yrs; high-risk/severe osteoporosis; follow with antiresorptive)
  • Calcitonin: Not routinely recommended; can reduce pain after fracture
  • HRT: Consider for select postmenopausal women

Procedures

  • Vertebroplasty/kyphoplasty: For compression fractures

Additional Therapies

  • Acupuncture (pain)
  • Yoga, tai chi (improve balance, reduce falls)

ONGOING CARE

  • Monitor: Annual height, repeat DEXA q2 years after starting therapy
  • Risk assessment after 3–5 years: if T-score ≥ -2.5 and no fracture, may stop; continue if high risk.
  • Bisphosphonate holiday: Consider after 5 years if low risk/stable, 6–10 years if high risk.
  • Dental exam: Discuss ONJ risk with all bisphosphonate patients

DIET

  • Calcium: Dairy, leafy greens, fortified plant milks
  • Vitamin D: Fatty fish, egg yolks, fortified cereals
  • Limit sodium/caffeine, moderate alcohol

PATIENT EDUCATION

  • Bone Health & Osteoporosis Foundation: link
  • International Osteoporosis Foundation: link

PROGNOSIS

  • 80% increase bone mass/mobility and reduced pain with treatment
  • 15% vertebral, 20–40% hip fractures lead to chronic care/death

COMPLICATIONS

  • Recurrent fractures (spine, hip, wrist, ribs)
  • Back pain, height loss, loss of independence, hospitalization, ↑ mortality (esp. hip fracture)

ICD-10 Codes

  • M85.80: Other specified bone density disorders, unspecified site
  • M81.0: Age-related osteoporosis without current fracture
  • M80.00XA: Age-related osteoporosis with current pathological fracture, unspecified site, initial encounter

Clinical Pearls

  • DEXA: Not for women <65 or men <70 with no risk factors
  • Repeat DEXA: Not more often than every 2 years
  • Bisphosphonates: Not >5 years in low-risk, not first-line in postmenopausal women with mild osteopenia
  • No routine use of bone turnover markers or calcitonin
  • Always address secondary causes in young or atypical presentations