Osteoporosis - Background Flashcards
Osteoporosis is a disease characterised by reduced ? ? ? and microarchitectural deterioration of bone tissue, leading to increased bone
? and an increased risk of ?.
WHO defines osteoporosis as bone mineral density >? SDs below that of a
young adult ?, with values between 1 and 2.5 described as ?.
Fractures related to osteoporosis are a major public health problem in
developed countries, affecting up to ?% of women and 12% of men.
bone mineral density fragility # 2.5 male osteopenia 30%
Pathogenesis
-In normal individuals, bone mass increases during ? to reach a peak
between 20-?, when there is a period of ? before it falls thereafter.
Women have an ? phase of bone loss after the ? as a
result of ? deficiency.
childhood 30 consolidation accelerated menopause oestrogen
Risk factors·
?.
? Sex.
Genetics: ?% of peak bone mass determined by genetics, also rate of bone
?.
Low peak bone mass: limited ? exercise, limited early ? intake and low body ? in childhood make up the environmental component.
Disuse: e.g. following a ?, leading to ‘disuse ?’.
?.
age female 80 turnover early calcium habitus # atrophy smoking
A ‘secondary’ cause of osteoporosis is identified in around ?% of male cases;
-? Hyper?: High ? leads to increase bone turnover,
which aggravates imbalances in ?/?.
-?: again increases bone turnover.
-Malabsorptive conditions: ? deficiency and secondary hyper?.
-Chronic ? disease/? disease: inflammatory ?
increase bone ? and suppress bone ?
50 prim parathyroid resorption/formation thyrotoxicosis calcium pth inflam neoplastic cytokines resorption formation
A ‘secondary’ cause of osteoporosis is identified in around ?% of male cases;
-Steroid-induced: risk is directly related to ?/? of therapy.
–> o Steroids cause decreased ? calcium absorption and increased
? calcium excretion, leading to secondary ?.
–> o This is combined with a direct inhibition of ? activity and stimulation of osteoblast ?.
-? disease: as for steroids.
-Anorexia Nervosa: ?deficiency, ? loss and ? all
contribute.
50 dose/duration intestinal renal hypPTH osteoblast apoptosis cushings calcium weight hypogonadism
Clinically the disease is mainly ?, often picked up ? if patients are undergoing X-ray imaging for another condition, and the bones will appear more ? than normal with looser zones.
If symptoms occur, they may be; ? fractures. ? pain. ? loss. ?sis.
aSx incidentally radiolucent fragility back height kyphosis
The most common sites for osteoporotic fractures are the ?(?), ? of
femur or ?(vertebral ?/?fracture).
After ? of these fractures is detected the patient should be referred on for bone ?·
wrist colles neck spine wedge crush one densitometry