The process Blood Absorption Bones Blood Resorption Bones Problem is the

The process blood absorption bones blood resorption

This preview shows page 19 - 22 out of 39 pages.

- The process: Blood Absorption Bones Blood Resorption Bones - Problem is the resorption process o Series of cells called osteoclast these cells liberate acid in their action and the acid is what picks away the bone material – takes away the calcium Leaves a spot/little space/pit with less bone material – it is weakened These cells are associated with the resorption of bone mass o Specific inhibitor of osteoclast – mediated bone resorption Fosamax (alendronate) inhibits osteoclasts from happening About 3% per year increase in bone mass (more specific to the hip) Some studies show that Fosamax affects the bone in the jaw (osteonecrosis of the jaw) - FDA approves Reclast to prevent osteoporosis in post-menopausal women with convenient less frequent dosing - Absorption process o Specific cells called osteoblast: matrix of protein and mineral material o Once the bone has been put together by the protein material, minerals namely calcium it is implanted by the osteoblast cells These cells are associated with the deposition of bone mass How can one tell if they have low bone mass? - Blood - X- ray - CT scan - Single-photon absorptiometry - Double-photon absorptiometry o Absorptiometry works the best o Non-invasive on the wrist - Average risk by calculation (FRAX) o Google it and you can analyze yourself Calcium buildup
Image of page 19
- Calcium build up in the arteries can cause hear-attacks in post-menopausal women o Significant studies done o One recent study of approx. 1500 women with a mean age of 74 taking calcium supplements has a approx. 50% chance of having either a heart attack or stroke compared to those taking a placebo - What to do? o It has been determine that calcium uptake is better when vitamin D is enhanced o More studies are needed to capture the best relationship with vitamin D and calcium Osteoporosis therapies - You need to have calcium o Caltrate (calcium carbonate) is a pill supplement o Tums supplements Idea is to take the supplements with meals as the acid secreted in the stomach enhances absorption o Proton Pump Inhibitors May interfere with calcium absorption through induction of hypochlorhydria but they also many reduce bone resorption by inhibiting the osteoclastic process - A recent analysis of a number of studies (a meta-analysis) showed that calcium supplementation may increase the risk for hip fracture by 60% o The reason is that the supplements are calcium citrate or calcium carbonate and these interfere with phosphate absorption - Calcium + vitamin D o Easy to take, not expensive o Adolf Windaus (Nobel prize 1928) eventually worked out vitamin D -3 o Vitamin D helps to maintain the calcium concentration at about 500 UG a day - Exercise o Stimulates bone density and bone absorption/bone mass - Estrogen o Estrogen receptors are found in bone cells so estrogen is needed Post-menopausal = estrogen levels decrease
Image of page 20
o For many years estrogen was said to help prevent osteoporosis and may help prevent heart disease. However it increases the risk of uterine cancer (very small
Image of page 21
Image of page 22

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture