Metabolic and endocrine diseases of the bone Flashcards
Osteomalacia
=disease where bones becomes soft and weak
aetiology–> vitamin D deficiency or digestive and kidney disorders
clinical presentation–> pain in bones and hips, bone fractures, muscle weakness, difficulty walking
findings–> test vit D levels (would be low), xrays to find evidence, bone mineral density test- info about patients bone health
pathophysiology–> The synthesis of active vitamin D (calcitriol) organically begins in the skin, where cholecalciferol (vitamin D3) is formed by the action of UVB radiation converting 7-dehydrocholesterol (provitamin D3) in epidermal keratinocytes and dermal fibroblasts to pre-vitamin D, which spontaneously isomerizes to form cholecalciferol. Subsequently, cholecalciferol gets transported to the liver, where it is converted to calcidiol, 25-hydroxyvitamin D [25(OH)D], by 25-hydroxylase (CYP2R1). Therefore, it is logical that patients with chronic liver disease would be at risk of developing vitamin D deficiency.
management–> vitamin D doses
ricket’s
=the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency
aetiology–> lack of vitamin D (food and sunlight), problems with absorption (celiac disease, IBS, cystic fibrosis, kidney problems)
clinical presentation–> delayed growth, delayed motor skills, pain in spine, pelvis and legs, muscle weakness, bowed or knock knees, thickened wrists/ ankles, breastbone projection
pathophysiology–> defect in vitamin D actions and/or hypophosphatemia. Vitamin D deficiency, inability of activation of vitamin D in vivo or functional derangement in vitamin D receptor is involved in impaired actions of vitamin D
management–> vitamin D and calcium supplements, bracing
paget’s disease
=fragile and misshapen bones
aetiology–> combination of environmental and genetic factors contribute to the disease. Several genes appear to be linked to getting the disease. possibly viral
clinical presentation–> bone pain
findings–> x rays- areas of bone breakdown, enlargement of the bone and deformities that are characteristic of the disease, such as bowing of your long bones. bone scan. blood tests- elevated levels of alkaline phosphatase
pathophysiology–> increase in bone resorption that leads to a decrease in bone mass and lytic structures. This process gives rise to osteoblasts from the bone utilizing a sensing system that allows them to increase their activity
management–> medications- Osteoporosis drugs (bisphosphonates). surgery- help fractures heal, Replace joints damaged by severe arthritis, Realign deformed bones, Reduce pressure on nerves
hyperparathyroidism
=when your parathyroid glands create high amounts of parathyroid hormone in the bloodstream
aetiology–> primary- a non cancerous growth, enlargement of 2 or more glands, cancerous tumour (rare). secondary (result of another condition that lowers the blood calcium, which then affects the gland’s function)- severe calcium deficiency, severe vitamin D deficiency, chronic kidney failure
clinical presentation–> osteoporosis (weak bones), kidney stones, excessive urination, abdominal pain, tiredness/ weakness, depression, bone/ joint pain, nausea
findings–> blood tests- high blood calcium levels combined with high levels of parathyroid hormone. bone mineral density test- to see if you have developed osteoporosis. urine test- how well kidneys are working. imaging tests of kidneys
pathophysiology–> parathyroid glands produce too much parathyroid hormone in your body. This causes your calcium levels to rise
management–> regular monitoring, surgery- remove enlarged glands/ tumours. medications- Calcimimetics (mimics calcium circulating in the blood), Hormone replacement therapy, Bisphosphonates
hypoparathyroidism
=when the parathyroid glands don’t produce enough parathyroid hormone
aetiology–> neck surgery creating accidental damage to glands, autoimmune disease, Hereditary hypoparathyroidism, Low levels of magnesium in the blood, Extensive cancer radiation treatment of the face or neck
clinical presentation–> Tingling or burning in the fingertips, toes and lips, Muscle aches or cramps in the legs, feet, stomach or face, Twitching or spasms of muscles, particularly around the mouth, but also in the hands, arms and throat, Fatigue or weakness
findings–> blood tests- A low blood-calcium level, A low parathyroid hormone level, A high blood-phosphorus level. urine test- see if body is getting rid of too much calcium
pathophysiology–> caused by a parathyroid hormone (PTH) deficiency or resistance, leading to hypocalcemia and hyperphosphatemia. PTH deficiency can be result from destruction or hypoplasia/agenesis of the parathyroid gland, or the impaired synthesis or secretion of PTH
management–> medication- oral calcium, vitamin D, magnesium, Thiazide diuretics, Parathyroid hormone replacement. diet- rich in calcium and low in phosphorus. intravenous fusion
