Osteoporosis

Question 1

What is the main problem that causes weak bones in osteoporosis?

Answer 1

Osteoclast activity is abnormally high, so that bone breakdown is happening at a faster rate than the rebuilding of bone by osteoblasts. (The two processes should occur at equal rates.)

Question 2

What protective effect on bones do the sex hormones like estrogen(and testosterone in men) have?

Answer 2

One of estrogen’s roles is to limit the breakdown of the skeleton caused by parathyroid hormone (PTH). This means estrogen “puts a brake” on PTH to make sure it can’t increase osteoclast activity too much.

Question 3

What happens at menopause that triggers osteoporosis?

Answer 3

At menopause, a woman’s body greatly reduces its production of estrogen. (This is because the ovaries stop making eggs). The low levels of estrogen can no longer keep PTH in check-so osteoclast activity shoots up, causing bone breakdown to get out of control.