Age

How does bone change over time?

Bone is a living and growing tissue. Throughout life, bone is constantly being renewed in a process called remodeling. During remodeling, old bone is removed (resorbed) and it is replaced with fresh new bone.

• Bone building occurs when more bone is laid down than removed.
• Bone mass is maintained when bone formation equals bone removal.
• Bone loss occurs when more bone is removed than replaced.

Why has osteoporosis been called a "childhood concern"?

During childhood, the teen years, and early adulthood the skeleton grows and bones become larger, denser, and stronger especially when you practice bone healthy actions. Peak bone mass, defined as the maximum bone density you will ever have, is usually reached between ages 18 and 25. The peak bone mass that you can reach is largely determined by your genetic makeup. You cannot change your genetics. Some people are born with the tendency to have thick bones and some are not. The goal is to do take bone healthy actions in order to reach the peak bone mass that your genetics will allow.

What are bone healthy actions?

Bone healthy actions to help you reach peak bone mass during youth include eating a balanced diet with adequate calcium and vitamin D and getting regular physical activity. In addition, it is important for young women to have regular menstrual periods. Estrogen, the female hormone that controls the menstrual cycles also protects the bones. To achieve peak bone mass, it is important for you to talk to your medical professional if you are a young woman with absent or irregular periods. Tobacco use and excessive alcohol consumption should be avoided since these substances may reduce peak bone mass. People who attain higher peak bone mass have larger and more dense bones and are less likely to get the bone-thinning disease called osteoporosis later in life.

What happens to bones in the adult years?

After age 25, most people no longer build bone mass. In adulthood, bone healthy actions are necessary to help you maintain your bone mass. Bone mass is usually maintained until the late forties, especially in the spine, but there may be some loss of bone in the hip even at this age. Maintaining your physical activity level is one important step to help prevent bone loss in the adult years.

At any adult age, your bone mass is the result of the amount of peak bone mass attained minus the amount of bone loss.

Your likelihood of getting osteoporosis depends on the amount of bone mass you achieve at peak and the rate and duration of bone loss. People with a low peak bone mass and a high rate of bone loss are more likely to develop osteoporosis. Those with a high peak bone mass and slow rate of bone loss are the least likely to get osteoporosis. Others have a risk that falls somewhere in the middle.

As men and women age, do they lose bone mass differently?

Women experience an earlier, much more dramatic loss of bone mass than men. The rapid loss of bone mass, 1% to 3% loss per year, occurs at the time of menopause and continues for about the next 3 to 5 years. Menopause is the permanent loss of monthly periods for 12 months in a row without another medical reason and usually occurs between the ages of 45 and 55. The rapid loss of bone mass is related to a dramatic, complete decline in the level of estrogen, the female hormone that protects bones. When several years have passed since menopause, the rate of bone loss slows down and then may increase again after age 70.

Men do not have a rapid bone loss with age because they do not experience a dramatic decline in either estrogen or testosterone (male hormone) levels. This helps protect men from osteoporosis. Men experience slower bone loss later in life, around age 70 years or older, when estrogen and testosterone levels start to decline.

Though bone loss at menopause and with advancing age is inevitable, the rate of loss varies among individuals. The rate of loss is influenced by genetic factors (that you cannot control) and lifestyle factors (that you can control). You can slow the rate of bone loss by taking bone healthy actions.

Does age influence the risk for fractures (broken bones)?

Broken bones as a result of osteoporosis generally do not occur until later in life even though damage to the skeleton can begin many years earlier. The risk for fractures in the spine and hip increases after about age 50 in both men and women. Spine fractures increase most dramatically beginning at age 50. The increase in the rate of hip fractures occurs later, after age 65. There are several reasons for the increased risk for broken bones with age including: the loss of bone, the reduced quality of bone and the increased risk of falling associated with age. If you were to compare two women with the same bone density, one age 50 and the other age 80, they would have very different risks for most types of fractures. The 80 year-old would have a risk for hip fracture several times greater than the 50 year-old.

Does age increase the risk of all types of fractures?

Age does not increase the risk of all types of broken bones. The risk of a wrist fracture does not increase steadily with age. In women, wrist fractures are more common after menopause but then the risk remains the same and even declines after age 65. This may occur because older women tend to be less active in activities that lead to the types of falls that tend to cause wrist fractures. In addition, studies have shown that elderly women tend to fall differently than younger women. This happens as a result of having less strength and slower reflexes resulting in being less able to quickly extend their arms during a fall.

At what age do I need to be concerned about my bones?

Bone healthy actions should begin in childhood and continue throughout your lifetime. The earlier that prevention measures are taken, the more impact they will have on reducing your risk for osteoporosis. Still, it's never too late to take action to promote healthy bones. Bone healthy actions are the keys to enable you to build strong bones in youth and maintain bone mass in adulthood.

For more information about aging well, click on The New York State Office for Aging website; http://aging.state.ny.us/