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Osteoporosis. Jiří Slíva, M.D. Osteoporosis. a bone disease that is characterized by progressive loss of bone density and thinning of bone tissue higher risk of fractures. Sceletal status by age. 25 yr – balance between bone resorption & formation - PBM (peak bone mass)
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Osteoporosis Jiří Slíva, M.D.
Osteoporosis • a bone disease that is characterized by progressive loss of bone density and thinning of bone tissue • higher risk of fractures
Sceletal status by age • 25 yr – balance between bone resorption & formation - PBM (peak bone mass) • duration approx. 5 yr • exaggerated resorption (0,5% /year) • climacterium
Risk factors for osteoporosis I • genetic factors • elderly • females • early climacterium (before 45. yr)
Risk factors for osteoporosis II • time after climacterium • late menarche • race differences – Caucasians, etc. • drugs – antiepileptics, etc. • diseases – malabsorption, Cushing sy
Concomitant factors • unhealthy lifestyle • low of calcium intake • lack of vitamin D • excessive alcohol intake • stress, smoking
Primary prevention • Increase of body performance – stimulation of osteoblasts • Sufficient intake of calcium – at least 1 g/d, people in higher risk up to 2 g/d • vitamin D - food, sun
Regulatory mechanisms of bone metabolism • parathormone • calcitonine • sexual hormones - estrogens & gestagens
Epidemiology • 7-8% population in CZ • 1/3 women after climacterium
Diagnosis • Anamnesis, clinical examination • Densitometry • Markers of resorption – pyridinoline in urine
Treatment • nonspecific…according to risk factors • specific
Calcium • stimulation of calcitonine x inhibition of parathormone • 1 000 mg/d
Vitamin D • at least 400 IU, in elderly up to 800 IU • formulations containing ergocalciferole, cholecalciferole • risk of overdosage
Antiresorptive treatment - HRT • Estrogens support bone synthesis & inhibit resorption • Proliferaratory effects are inhibited by gestagens • Referral from EMEA
SERM • selective modulators of estrogen receptors • non-steroidal structure • protection of endometrium • raloxifen, tamoxifen, droloxifen
Calcitonine • inhibition of osteoclasts, increase of tubular reabsorption of calcium, analgesic eff., stimulatuon of bone formation • calcitoninum salmonis or humanum (200 IU)
Bisphosphonates • Influence on calcium metabolism • Inhibition of resorption (via cytotoxicity on osteoclasts?) • Accumulation in bones • Elimination via kidneys
Bisphosphonates • 1st generation - etidronate, clodronate • 2nd generation - pamidronate, alendronate • 3rd generation - risedronate, ibandronate • CI – disease of oesophagus, stomach or kidneys, pregnancy, lactation
Thiazide diuretics • diminished renal excretion of calcium; ??? increase of BMD ??? • good for patients with hypertension
Drugs stimulating bone formation • fluoride -? MÚ, 14ti měsíční cykly (12+2) • vitamin K • magnesium • STH – increased activity of osteoblasts • Parathormone ??? • promethazine