Postmenopausal osteoporosis

Definition

• Osteoporosis is a systemic skeletal disease with low bone mass and distorted microarchitecture, leading to increased fracture susceptibility; in the postmenopausal form, oestrogen deficiency predominates.
• According to the WHO, osteoporosis is present at a DXA T-score of −2.5 SD or lower; severe (established) osteoporosis additionally requires at least one fragility fracture.

Classification

• Primary postmenopausal (type I) osteoporosis is due to oestrogen deficiency; senile (type II) osteoporosis is mainly age-related and affects women about twice as often as men.
• Secondary osteoporosis due to other underlying diseases or substances accounts for up to 30% of osteoporosis in postmenopausal women.

Occurrence & epidemiology

Epidemiology

• Most cases of osteoporosis occur in postmenopausal women and older men; peak bone mass is reached around the age of 30.

Aetiopathogenesis

Aetiology and pathogenesis

• With menopause, bone loss accelerates to about 2% per year for about 10 years; trabecular bone is lost faster than cortical bone because of its higher turnover.
• Risk factors include older age, a positive family history especially of parental hip fracture, low body mass index, immobilisation, smoking, alcohol and insufficient calcium or vitamin D intake.

Clinical features

• The disease is asymptomatic until a fracture occurs; vertebral compression fractures are the most common osteoporotic fractures, but about two-thirds of them remain asymptomatic.
• Typical fracture sites are the thoracic and lumbar spine, femoral neck and distal radius; multiple vertebral fractures lead to height loss and kyphosis.

Diagnosis

• Bone mineral density is measured by DXA, usually at the spine and hip; if these sites are unsuitable, the distal radius (1/3 radius) is used.
• Regardless of bone mineral density, osteoporosis can also be diagnosed on the basis of a fragility fracture, particularly of the spine, hip, humerus or distal radius.
• Secondary causes are sought with calcium, phosphate, 25-hydroxyvitamin D, liver tests including alkaline phosphatase, parathyroid hormone and 24-hour urine calcium and creatinine, supplemented by TSH and blood count depending on the clinical picture.

Keep learning in the app

Further reading (selection)

1. MSD Manual Professional: Osteoporosis
2. Educational Case: Osteoporosis (Acad Pathol 2022, PubMed Central)
3. Beyond the T-Score: A Narrative Clinical Review of Adult Endocrine Osteoporosis Care (J Clin Med 2026, PubMed Central)

Cross-references