Osteoporosis is a skeletal disease characterized by low bone density and deterioration of bone microarchitecture, leading to increased bone fragility and fracture risk. It is often called a "silent disease" because bone loss occurs without symptoms — until a fracture happens. Osteoporosis affects 10 million Americans, and another 44 million have low bone mass (osteopenia), placing them at increased risk.
Who Is at Risk?
Risk factors include:
- Female sex (women have lower peak bone mass and accelerated bone loss after menopause)
- Age (bone density peaks in the late 20s and gradually declines)
- Family history of osteoporosis or hip fracture
- Low body weight
- Long-term glucocorticoid (steroid) use
- Smoking and excessive alcohol use
- Low calcium and vitamin D intake
- Sedentary lifestyle
- Early menopause or prolonged low estrogen
- Secondary causes: hyperthyroidism, hyperparathyroidism, malabsorption, multiple myeloma, and others
Diagnosis — Bone Density Testing (DEXA)
Bone mineral density (BMD) is measured by dual-energy X-ray absorptiometry (DEXA scan), which measures the hip and spine. Results are reported as a T-score:
| T-score | Interpretation |
|---|---|
| -1.0 or above | Normal bone density |
| -1.0 to -2.5 | Osteopenia (low bone mass) |
| -2.5 or below | Osteoporosis |
DEXA screening is recommended for all women 65+ and for younger postmenopausal women with risk factors. The FRAX tool (WHO fracture risk assessment) combines BMD with clinical risk factors to estimate 10-year fracture probability and guide treatment decisions.
Prevention
- Adequate calcium intake: 1,000 mg/day for adults under 50; 1,200 mg/day for women 51+ and men 71+
- Vitamin D: 2,000 IU/day; higher doses for those who are deficient
- Regular weight-bearing exercise (walking, jogging, dancing) and resistance training
- Avoid smoking and limit alcohol
- Fall prevention strategies (balance exercises, home safety assessment)
Treatment
Pharmacological treatment is recommended for:
- Osteoporosis diagnosis (T-score ≤ -2.5)
- Fragility fracture (hip or vertebra)
- Osteopenia with a high FRAX 10-year fracture risk (≥3% hip, ≥20% major)
Medication options:
- Bisphosphonates (alendronate, risedronate, zoledronate): First-line; reduce fracture risk by 40–70%; oral weekly/monthly or IV yearly
- Denosumab (Prolia): Injectable every 6 months; highly effective; requires careful monitoring of calcium and rebound if discontinued
- Teriparatide / Abaloparatide: Anabolic (bone-building) agents; used for severe osteoporosis; daily injections for up to 2 years
- Romosozumab (Evenity): Dual-action (builds bone and reduces breakdown); monthly injection for 1 year; for very high-risk patients
- Hormone therapy: Estrogen reduces fracture risk; may be appropriate for postmenopausal women with osteoporosis who also have menopausal symptoms
Key Takeaways
- Osteoporosis is a "silent disease" — fractures are often the first sign
- DEXA scan measures bone density — screening recommended for all women 65+
- Calcium, vitamin D, exercise, and fall prevention are the foundation of care
- Multiple effective medications reduce fracture risk by 40–70%
- An endocrinologist should evaluate for secondary causes and guide treatment decisions