En español | The human body consists of 206 bones, in which minerals—mainly calcium—are amazingly stored in a delicate tissue called the bone matrix. This combination of elements forms what is considered one of the hardest substances in the human body: bone. Bones are the frame that supports all other organs, and they are essential for maintaining posture and undergoing physical activity.
Unfortunately, due to age, as well as other factors, bones lose some of their density and become more brittle and fragile. When this weakening reaches a critical stage, bones can easily be broken. This condition is called osteoporosis, a bone disease affecting about 44 million Americans, mainly women.
In order to understand what osteoporosis is, we must first understand bone formation. Bone metabolism is extremely active and, like the famous Penelope's web, bone tissue is constantly being built up and destroyed. Bones are formed by osteoblasts, which are very active cells that build up the tissue on which calcium and other minerals are stored. Osteoclasts, on the other hand, can be described as bone-destroying cells, causing the bone to lose its mineral storage. During childhood and adolescence, osteoblastic activity (construction) is much greater than osteoclastic activity (destruction). The net result is the growth of strong and solid bone. But after about age 35, the osteoclasts’ destructive activity becomes greater than the osteoblasts' constructive activity. As a result, bones lose density and osteopenia begins; if it continues to develop, osteoporosis occurs at a later stage.
The good news is that the weakening of our bones can be diagnosed by means of a bone densitometry test. This painless test measures bone hardness or density in two places: the spine and the hip. However, other modern but less accurate equipment can also measure bone density in other places (including the finger, wrist, or heel). The result of this test is expressed using two different numbers called the T-score and the Z-score. The T-score is the more important, and compares a patient's bone density with that of an average 30-year-old of the same gender. Because an older person's bone density is always lower than that of a younger individual, his or her T-score is expressed as a negative number. If this number is between -1 and -2.5, the analyzed bone sample has osteopenia. If the T-score is lower than -2.5, the patient is diagnosed with osteoporosis.
According to the National Osteoporosis Foundation, all women over 65 should undergo a bone densitometry test. It is recommended that younger postmenopausal women have the test done if they have suffered bone fractures; are receiving chronic medical treatment with glucocorticoids, Dilantin, or barbiturates; weigh less than 127 pounds; or smoke. For men, there are no hard and fast rules regarding when to have a bone densitometry test, although it is thought that men with low testosterone levels should be tested.
There is no cure for osteoporosis, but once osteopenia or osteoporosis has been diagnosed, physicians can prescribe medication to reduce the risk of bone fractures in the future. As far as prevention, a calcium-rich diet, regular exercise, and an adequate intake of calcium and vitamin D supplements have proven helpful in delaying the onset of osteoporosis.
To sum up, osteopenia and osteoporosis are like grey hair and wrinkles: they are natural processes that happen over time. However, they can be prevented and detected in good time, before they cause problems.