What is osteoporosis?

Osteoporosis is a skeletal condition in which the amount of bone per unit volume is decreased but the composition is normal. In other words the bones are weak, fragile and may be fractured easily. In fact osteoporosis is responsible for at least 1.2 million fractures per year in the USA alone. The most common sites of these fractures are the vertebrae, the hip, the radius (forearm).

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How does osteoporosis?

Normally bone is in a constant state of remodeling. There are three types of bone cells that are responsible for this turn over:

1. Osteoblasts deposit the bone matrix forming a continuous membrane over cash bone and actively transports materials across this membrane to initiate calcification (the building up of bone).
2. Osteoclasts secrete enzymes that dissolve the matrix originally formed by the osteoblasts, breaking down the bone.
3. Osteocytes reabsorb as well as redeposit done.

Osteoporosis occurs when bone formation (osteoblasts) lag behind bone resumption (osteoclasts). The loss of skeletal mass is an universal age-related phenomenon that occurs as part of the natural aging process, and osteoporosis is an exaggeration of this phenomenom.

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What is the normal rate of bone loss?

Both men and woman show a steady increase in bone mass until around the late 20's /early 30's; at this point bone mass begins to decrease, at a normal rate of 2% per year. Bone loss begins earlier and proceeds more rapidly in women. When 20-40% of bone mass has been lost, the decrease in bone mass plateaus. People with osteoporosis lose bone at a rate of greater than 2% per year. This condition is thought to be an irreversible process. Once bone loss has progressed beyond a certain point, bone mass cannot be regained.

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Why does the rate of bone loss increase significantly at the time of menopause?

Circulation estrogen levels play a major role in conditioning the rates of bone loss in woman between the ages of 42 and 58, and at the time of menopause circulation estrogen levels significantly decline. Specifically, estrogers are believed to inhibit osteoclastic activity; in other words if there is little circulating estrogen–as in postmenapausal woman–there is nothing to suppress bone break down, so the rate of bone resumption increases while the rate of bone formation remains constant. In fact estrogen deficiency can result in up to a 2-fold increase in bone turn over and an increased loss of vertebral trabecular bone that may me as great as 5%-10% per year.

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What are some other predisposing factors?

Genetic:

• White or Asiatic ethnicity
• Positive family history
• Small body frame (less than 12716

Life style:

• Smoking
• Inactivity
• Excessive exercise (producing amenorrhea)
• Early natural menopause
• Late menarche

Nutritional factors

• Milk intolerance
• Lifelong low dietary calcium intake, vegetarian dieting
• Excessive alcohol intolerance
• High protein intake