Sufficient bone density is critical to our ability to get around and move properly. Bone density is also important in preventing fractures. As we age, the mineral content of our bones decreases and as a result, their density decreases. Low bone density causes osteoporosis, a debilitating condition in which the bones become weak, brittle, and fracture easily. The precursor to osteoporosis is osteopenia. According to the medical website UpToDate, osteoporosis caused by low bone density leads to 1.5 million fractures in the United States each year. By understanding the causes and risk factors of low bone density and how it can be prevented and treated, you can take an active role in maintaining your bone density.
Bone Density Measurement
Bone density is assessed using a test called dual x-ray absorptiometry, also called DXA. This test uses a special kind of x-ray to calculate total body bone density with special attention paid to common fracture sites, such as the spine, hip, and forearm. According to Boston's Brigham and Women's Hospital, the test requires the patient to lie down for a few minutes and sit for a few minutes while a scanning arm x-rays the designated site. The test results are expressed with a "T" score and a "Z" score. The T-score compares your bone density with that of a healthy young person, while the Z-score compares your bone density with that of your same-age peers. According to UpToDate, a T-score of +1 to -1 is normal, whereas a T-score of -1.1 and -2.4 indicates osteopenia and a T-score of -2.5 or less indicates full-blown osteoporosis.
Causes and Risk Factors for Low Bone Density
Our bones are in dynamic flux--bone cells are constantly being destroyed and regenerated. A natural part of aging is an increase in bone destruction or resorption proportional to bone regeneration, leading to the loss of bone density. However, certain people are at greater risk for losing substantial bone density that could eventually lead to osteoporosis. Women are at greater risk than men, especially after menopause. According to MayoClinic.com, other risk factors include low body weight, a personal history of fractures after age 40, a parental history of osteoporosis, the use of steroid-containing medications, and ethnicity--women of Caucasian and Southeast Asian descent are at greatest risk. It is important that people with risk factors for bone density problems are proactive in taking prevention steps and talk to their doctor sabout DXA scanning.
Consequences of Low Bone Density
Consequences of low bone density include increased risk of fractures and decreased mobility. According to UpToDate, 50 percent of people who break a hip never regain the ability to walk without assistance, while 25 percent will require long-term care after the break. According to Brigham and Women's Hospital, a women's risk of hip fracture is equal to her combined risk of breast, ovarian, and uterine cancers. In essence, for many older people, reduced bone density can mean a loss of independence, a significant quality of life issue.
Osteopenia and Osteoporosis
Osteopenia is a precursor to osteoporosis, the debilitating condition that affects approximately 44 million Americans, according to Brigham and Women's Hospital. Osteoporosis is characterized by low bone density and structural deterioration of the bone. It is frequently referred to as a silent disease, because many people don't know they have it until they fracture a bone. Other symptoms of osteoporosis include height loss or stooped posture as a result of collapsed vertebrae.
Prevention and Treatment of Low Bone Density
Prevention of bone density problems can be best achieved through diet and weight-bearing exercise. Important dietary factors in maintaining and improving bone density are calcium and vitamin D. Good dietary sources of calcium include dairy products and dark leafy greens, like spinach. Vitamin D can be found in egg yolk and saltwater fish, and is also absorbed by the skin through sunlight.
Weight-bearing exercise helps to stimulate bone growth. Good weight-bearing exercises include walking, weight-lifting, and stair-climbing. Additional calcium and vitamin D can be acquired through vitamins and supplements. Lastly, medication can also be used to increase bone density, especially in the case of osteopenia and osteoporosis. According to the National Institutes of Health, these include biphosophates and estrogen treatment.
