OSTEOPOROSIS-PATHOPHYSIOLOGY

SUMMARY

TYPES
1. Generalized (affecting whole skeleton) loss of bone mass: primary OP (type I) affects post-menopausal women; age-associated OP (type II) affects individuals > 70 yrs; secondary OP (type III) caused by diseases.

2. Discrete loss of bone mass: primary (RSD); secondary (immobility, malignancy, necrosis, inflammation).

PATHOPHYSIOLOGY
3. Increased rate of bone loss: after PBM is achieved, bone loss occurs gradually thereafter, with the most rapid bone loss occurring in the early post-menopausal period in females. Lifetime bone loss: 20% to 30% in males, 45% to 50% in females.

4. Poor quality of bone microstructures: decreased trabecular bone (trabecular perforation).

5. Failure to achieve adequate PBM at skeletal maturity: risk factors including female athlete triad, anorexia, decreased mobility, nutritional deficiencies.

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].