Bone up on the facts

Think osteoporosis is just an affliction of grandmothers?
You're wrong.
Think osteoporosis is curable?
You're wrong.
Think osteoporosis is preventable?
You're right.

by Sheri B. Doniger, DDS

Think osteoporosis is just an affliction of grandmothers?
You're wrong.
Think osteoporosis is curable?
You're wrong.
Think osteoporosis is preventable?
You're right.

Taken from the Web pages of RDH is the statement, "The National Osteoporosis Foundation estimates that 44 million Americans are at risk for osteoporosis, particularly menopausal and postmenopausal women, yet 97 percent of boomers do not discuss their risk of this debilitating disease with their dentist." Although osteoporosis usually affects older individuals, it is not just a disease of the aged.

Osteoporosis affects 44 million people annually, with the greatest risk (80 percent of the patients) being women. In America, eight million women and two million men have osteoporosis. Millions more have low bone density. One out of two women and one in eight men over the age of 50 will have an osteoporosis-related fracture in their lifetime. Osteoporosis is defined as a disease of low bone mass and deterioration of existing bone, rendering the bones more fragile and less resistant to fracture, especially in the hip and spine. Osteopenia is characterized by low bone density due to the imbalance of bone formation and bone resorption.

The World Health Organization established the standards of diagnosis in 1994. Osteopenia has bone density values between 1 and 2.5 standard deviations below the average bone density of a young person. Osteoporosis has bone density values of less than 2.5 standard deviations. These levels are determined by a DEXA or dual energy X-ray absorptiometry. These scans evaluate areas of your body (hip, femur, spine) to determine osteoporosis before the fracture occurs, predict the chances of future fractures, and determine the rate of bone loss or monitor the treatment regimen.

The two major causes of osteoporosis are senile or postmenopausal osteoporosis. The former is a result of increasing age in both sexes; the latter, the bone loss that occurs in women after menopause. Up to 20 percent of bone mass can be lost in the five to seven years postmenopause. Men lose approximately 0.4 percent of bone mass per year after the age of 50. After the sixth decade, both sexes lose bone mass at about the same rate and have diminished calcium absorption.

Other causes of osteoporosis include the following:

  • Vascular diseases (anemia)
  • Medications (chronic steroid usage)
  • Dietary deficiencies (anorexia nervosa, malnutrition, and calcium deficiencies)
  • Congenital causes (osteogenesis imperfecta)
  • Alcohol abuse
  • Chronic liver disease
  • Diabetes mellitus
  • Hyperparathyroidism
  • Cushing's diseaseAcromegaly
  • Hypogonadism

Risk factors vary with the sexes. Women have a higher risk than men due to the hormonal variations induced with menopause or surgically induced menopause.

Additional risk factors exist for women:

  • Small, thin frame
  • History of amenorrhea
  • Eating disorders, such as anorexia nervosa, poor diet (especially low in calcium), and inactive or unhealthy lifestyle (excessive use of alcohol and smoking)

For males, the risk factors include the following:

  • Low levels of testosterone
  • Certain medications, especially steroids
  • Chronic diseases

Premenopausal women are at risk of low bone density. Peak bone mass usually occurs by late adolescence into the early twenties (90 percent by age 18). Trabecular bone may be more affected by premenopausal bone loss than cortical bone. Both the mandible and lumbar spine are rich in trabecular bone. Amenorrheic premenopausal women (those who have missed three or more menstrual periods) have lower bone density, especially in the spine. Their fracture risk is particularly high. They have a decreased level of estradiol, which is the primary form of estrogen. Many studies link estrogen-replacement therapy to increasing bone densities.

A physically active lifestyle and good calcium nutrition is key to premenopausal bone health. A calcium intake of 1,000 mg a day can prevent bone loss. Resistance training and high-impact exercises also help bone density. Any activity that allows bones and muscles to work against gravity is strongly recommended. But one treatment needs to be done in conjunction with another. An active lifestyle with a poor calcium nutrition base will not yield the proper benefits. The seesaw diets that young women maintain also can be detrimental to bone health. To the extreme, anorexia nervosa yields a double whammy: secondary amenorrhea, causing low estrogen, and restricted dietary intake, impairing nutrition. The bone density lost with these patients may not be recovered when they achieve health and their normal cycle.

Osteoporosis, which is a major public health concern, is not curable. But it is preventable and treatable. These strategies can help:

  • Stay active and get plenty of exercise.
  • Eat foods naturally high in calcium and take supplemental dietary calcium (1,000 to 1,200 mg per day, depending on your age and sex) and vitamin D (200 IU to 600 IU, again depending on age and sex).
  • Maintain a healthy lifestyle (do not drink to excess or smoke).
  • Treat any underlying conditions that could affect bone density.

Weight-bearing exercises are recommended to slow mineral loss in patients of any age. Brisk walking, which causes minimal risk to joints, can be performed anywhere. A mile a day is most beneficial. Other recommendations include using a stationary bike, stair-climbing machine, or rowing machine, all of which work on the bones in the hip, legs, and lower spine. Resistance training — including free weights, water aerobics, weight machines, and elastic bands — all work the muscles and bones in the upper arms and spine. Back-strengthening exercises — including yoga, Pilates, and generalized stretching — will improve posture muscles. These exercises can be done by any age and at any ability level. One of the problems is that the age group most in need of high-resistance, weight-bearing exercises has the highest attrition rate for maintaining a continuous exercise routine.

Several medications are used in the prevention and treatment of osteoporosis: estrogen, alendronate sodium, risedronate sodium, raloxifene, and calcitonin. All of these are antiresorptive drugs, which affect the bone remodeling cycle. In osteoporosis, more osteoresorption occurs than osteogenesis. These drugs slow or stop the bone-resorption part of the cycle, but do not affect bone formation. Generally, these drugs reduce bone loss, increase bone density, and reduce the risk of fracture. Various medication doses are used, ranging from once a week to daily. Alendronate and risedronate are used to treat glucocorticoid-induced osteoporosis in both men and women. Alendronate also is used to treat osteoporosis in men. Side effects for each product vary. The link between estrogen and breast cancer is still under study.

Dentally, the alveolar bone is mainly trabecular bone. This type of bone is more susceptible to osteoporosis. Studies have found relationships between systemic bone loss and increased resorption of alveolar bone. Estrogen therapy has shown some significance in overall health. More studies need to be made on the correlation between estrogen HRT (hormone-replacement therapy) and alveolar bone loss due to periodontal disease and osteoporosis. The relationship between bone loss, periodontal disease, and tooth loss does exist. Several studies exist, but research has been limited. One three-year study demonstrated a 1.8 percent improvement in alveolar bone density among those taking estrogen, in addition to calcium and vitamin D, compared to a 1 percent increase in the placebo group taking only the calcium and vitamin D supplements. One study discussed calcium intake increasing bone density. It appears that the diseases share etiologic agents, which affect both periodontal disease and osteoporosis. Again, more research is necessary. Additionally, studies have been conducted on women who have been surgically induced into menopause as well as those who have entered menopause naturally. Research is needed to differentiate between the benefits of therapies restoring periodontal bone with estrogen for both categories of women. Currently, few studies exist.

With the increasing number of baby boomers, and the general health of our dental population always at risk, we need to be aware of this silent disease. Rarely are there symptoms of osteoporosis until a fracture occurs. One study indicated that half of the women who found out they had osteoporosis did not seek treatment after a year, placing them at a higher risk for fracture as time goes on. Since there is no cure, we should take steps to slow or stop its progress. We need to be diligent in questioning patients about their nutritional health, discussing physical activity, and alerting them of this quiet, debilitating disease.

The author wishes to thank Dr. Terry J. Annex and Dr. Linda Holt for their research assistance. References available upon request.

Sheri B. Doniger, DDS, practices in Lincolnwood, Ill. She graduated from the University of Illinois College of Dentistry in 1983 and obtained her bachelor's degree in dental hygiene from Loyola University of Chicago in 1976. She can be reached at (847) 677-1101 or donigerdental@aol.com.

For more information

•National Institutes of Health: Osteoporosis and Related Bone Diseases National Resource Center — www.osteo.org
•National Osteoporosis Foundation — www.nof.org
•University of Washington School of Medicine — www.rad.washington.edu/mskbook/osteopenia.html

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