• Quantitative reduction of normal bone → risk of fractures, pain, bone deformity

Etiology/classification:

1. Primary – Osteopenia without an underlying disease or medication

• Idiopathic type – rarely, in young pt
• Involutional type – postmenopausal women and geriatric patient

Contributing factors:

• Race (more in caucasians and asians)
• Gender: F > M.
• Reduced physical activity (convalescence and old age)
• Oestrogen, calcitonin and androgen deficiencies
• Malnutrition states
• Hyperparathyroidism
• Vitamin d deficiency

2. Secondary – due to:

A. Endrocrine disorders:

• Hypogonadism
• Hyperparathyroidism
• Pituitary tumours
• Type 1 diabetes
• Addison disease
• Thyrotoxicosis

B. Neoplasia: multiple myeloma, carcinomatosis
C. Git problems: malnutrition, malabsorption, hepatic insufficiency, vit c & d deficiency
D. Medication: corticosteroids, anticonvulsants, heparin, alcohol
E. Miscellaneous: immobilization, anemias, pulmonary disease

Radiology: Enlargement of the medullary cavity + thinning of cortex

Histology:

• Active type – ↑ bone turnover – by osteoblastic and osteoclastic activity with new osteoid formation
• Inactive osteoporosis – almost normal bone structure

Lab: ↑ serum phosphatase

Management: Hormone replacement therapy, manage other underlying causes

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