Aging Begins at 30

Take Precautions To Avoid Rapid Loss of Bone Mass

Bones thin as we grow older, beginning at age 30. Women lose extra bone at and after the menopause because their ovaries no longer produce estrogen, a bone-weight maintainer. At age 75, men have lost 15% of their bone and women 30%. At 75 about half of all women have one fracture due to bone thinning (osteoporosis). There is less bone than there was but what bone there is, is normal. Each year in the United States, 1.5 million fractures can be attributed to osteoporosis, costing $13 billion. Osteoporosis is not normal aging.

Lost are trabeculae, "little beams" in Latin, or struts that strengthen cancellous (latticed in Latin) bones found in the spine, upper arm, lower arm, wrist, and the upper thigh. So women in their 60s and older if they have osteoporosis get fractures of the back with height loss, or upper arm, or wrist (Colles) fracture or worst of all break their hip. The lifetime risk of a white women developing one of these fractures is 40%. In men it is 13%, equivalent to prostate cancer risk.

As with high blood pressure (and stroke) or high cholesterol (and heart attack) osteoporosis is an underlying factor leading to a medical catastrophe. There are often no symptoms until a fracture. A few weeks ago my wife broke her hip. She has four generations of osteoporosis among women in her family. She had already broken all the bones mentioned above as well as many ribs.

In contrast, cortical (bark like) bone is the compact bone of the shaft of bones that surrounds bone marrow. In osteoporosis it thins too but not so much. Your skeleton has preventive maintenance with continuous formation and destruction of bone. The annual turnover rate of cancellous bone is 25% and that of cortical bone is 2.5%.

Peak bone weight is reached at the end of the third decade and then there is steady attrition. This is determined by genetic influences, race (white women have a greater risk than black), gender, calcium intake, sexual maturation, and exercise. Mother-daughter and twin studies have shown that heredity may be responsible for 70% of peak bone mass, which explains family cases. For women entering the menopause trabecular bone loss is about 1% per year. Some women have an accelerated bone loss of 5% beginning at the menopause and continuing for 15 to 20 years. Post menopausal women require more calcium to maintain balance. Routine x-rays are not sensitive enough to diagnose early bone loss in the absence of fracture, as 30% can be lost before it is seen. Dual energy x-ray absorption is needed.

The best treatment is prevention. Smoking and excessive drinking should be avoided. Sufficient calcium and Vitamin D is important. Weight-bearing exercise is needed to increase muscle mass and improve balance, and stimulate bone growth. Estrogen replacement therapy should be considered at the time of the menopause. It increases spine bone density by 5% and reduces vertebral and hip fractures by 50% in some studies. Bed rest must be avoided as it leaches out calcium. Falls must be prevented. Other alternatives include calcitonin-salmon nasal spray, a bone depositing hormone from the thyroid. Biphosphonates (Alendronate) has bone-thinning prevention properties. The most effective time to intervene is around the menopause.

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See related Patient Topics Bones, Joints and Muscles, Osteoporosis, Seniors' Health or Women's Health.

See related Provider Topics Bones, Joints and Muscles, Osteoporosis, Seniors' Health or Women's Health.

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