Osteoporosis

Definition:

• Osteoporosis is a skeletal disorder characterized by compromised bone strength, predisposing individuals to an increased risk of fractures.

Epidemiology:

• Common, especially in postmenopausal women and older men.
• Risk increases with age.

Pathophysiology:

• Bone remodeling imbalance: Bone resorption outpaces bone formation, leading to decreased bone mass and deterioration of bone microarchitecture.
• Key cells involved: Osteoclasts (bone resorption), osteoblasts (bone formation).

Risk Factors:

• Non-modifiable: Age, female gender, family history, postmenopause, history of fractures.
• Modifiable: Smoking, excessive alcohol intake, low body weight, poor nutrition, physical inactivity, certain medications (e.g., glucocorticoids).

Clinical Features:

• Often asymptomatic until a fracture occurs.
• Fractures typically occur in the hip, spine, and wrist.
• May present with height loss, back pain, or a stooped posture.

Diagnosis:

• Bone Mineral Density (BMD) testing using dual-energy X-ray absorptiometry (DEXA) scan.
• Diagnosis based on T-score:
  • Normal: T-score above -1.0
  • Osteopenia: T-score between -1.0 and -2.5
  • Osteoporosis: T-score at or below -2.5
• Laboratory tests to exclude secondary causes.

Management:

• Lifestyle modifications: Diet rich in calcium and vitamin D, regular weight-bearing and muscle-strengthening exercises, fall prevention.
• Pharmacological treatment: Bisphosphonates are first-line. Other options include denosumab, selective estrogen receptor modulators (SERMs), teriparatide.
• Treatment of underlying conditions contributing to bone loss.

Prevention:

• Early lifestyle modifications.
• Screening at-risk populations.

Key Points for Medical Students:

1. Understand the pathophysiology of bone remodeling and the factors leading to osteoporosis.
2. Recognize the importance of early identification and prevention, especially in at-risk groups.
3. Be familiar with the use of DEXA scan for diagnosis and monitoring.
4. Know the various treatment options and their indications.