Understanding Bone Structure and Loss
Your skeleton is remodelled throughout life: osteoclast cells clear away worn bone, and osteoblast cells lay down fresh bone to replace it. In youth, bone is formed faster than it is broken down, reaching peak bone mass in the late 20s. After 35, bone density naturally starts to decline. In osteoporosis, bone is broken down faster than it is replaced, leaving bones weak and fragile.
The Menopause Connection
The most significant risk factor for osteoporosis in women is the menopause. Oestrogen plays a crucial role in maintaining bone density by inhibiting osteoclast activity. After the menopause, oestrogen levels fall sharply, accelerating bone loss. Women can lose up to 20% of their bone density in the 5–7 years following menopause.
Diagnosing Osteoporosis: The T-score
A DEXA scan measures bone mineral density (BMD) and compares it to that of a healthy young adult. The result is expressed as a T-score:
- T-score above -1: Normal bone density
- T-score between -1 and -2.5: Osteopenia (low bone density, precursor to osteoporosis)
- T-score below -2.5: Osteoporosis
Treatment in Detail
- Bisphosphonates (alendronic acid, risedronate) — inhibit osteoclast activity; most commonly prescribed; taken as a weekly tablet
- Denosumab (Prolia) — a biologic injection given every 6 months; an alternative for those who cannot tolerate bisphosphonates
- Hormone replacement therapy (HRT) — effective for postmenopausal women; also treats menopausal symptoms
- Teriparatide — an anabolic treatment that stimulates bone formation; used in severe osteoporosis
- Calcium (1,000–1,200mg/day) and Vitamin D (800–1,000 IU/day) supplements — essential alongside all treatments
Fall Prevention
Since fractures occur when fragile bones are subjected to trauma (usually falls), fall prevention is as important as bone-strengthening. Balance exercises (such as tai chi), reviewing medications that cause dizziness, improving home safety (removing trip hazards, adding grab rails), and wearing appropriate footwear all significantly reduce fracture risk.