Glossary · Conditions

Osteoporosis

Definition: Osteoporosis is a skeletal disease of low bone mass and disrupted bone microarchitecture, leading to fragility fractures. Postmenopausal estrogen deprivation accelerates bone loss for the first 5–7 years after the final menstrual period. HRT, bisphosphonates, denosumab, and other therapies all reduce fracture risk.

Detailed definition

Osteoporosis is defined by the WHO as a bone mineral density (BMD) ≥2.5 standard deviations below the young-adult mean (T-score ≤ -2.5) at the hip or lumbar spine on dual-energy X-ray absorptiometry (DEXA). Osteopenia is a T-score between -1.0 and -2.5. Women lose roughly 10% of bone mass in the 5–7 years around menopause, driven by estrogen-deprivation-induced acceleration of osteoclast activity. Lifetime fracture risk for a 50-year-old US woman is approximately 50%. The hip, spine, and distal radius are the most fragility-fracture-prone sites. Risk assessment uses BMD plus FRAX (a 10-year fracture risk calculator). Pharmacologic options include HRT (effective for prevention, with measurable BMD increases), bisphosphonates (alendronate, risedronate, zoledronic acid), denosumab, raloxifene (a SERM with breast cancer benefit), teriparatide (anabolic), abaloparatide, and romosozumab. Lifestyle measures — weight-bearing exercise, adequate calcium and vitamin D — are foundational.

Why it matters in menopause

For women who start HRT in the timing window primarily for vasomotor symptoms, the bone protection is a substantial bonus benefit. For women with established osteoporosis after age 60, HRT alone is generally not first-line — bisphosphonates or denosumab are preferred — but HRT remains useful for women with combined symptoms and bone-density concerns. ClearedRx routinely incorporates DEXA results into treatment decisions for women with bone-density concerns.

Sources

External references: Wikipedia · NLM MeSH.

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