Osteoporosis risk factors

The risk of getting osteoporosis increases with age as bones normally become thinner. After age 30, the rate at which your bone tissue dissolves and is absorbed by the body slowly increases, while the rate of bone building decreases. In women, bone loss is more rapid and usually begins after monthly menstrual periods stop, when a woman's production of the hormone estrogen slows down (usually between the ages of 45 and 55). A man's bone thinning typically starts to develop gradually when his production of the hormone testosterone slows down, at about 45 to 50 years of age. Women typically have smaller and lighter bones than men. As a result, women develop osteoporosis almost 4 times more often than men.¹ Osteoporosis usually does not have a noticeable effect on people until they are 60 or older.

Whether a person develops osteoporosis depends on the thickness of the bones in early life, as well as health, diet, and physical activity later in life. Factors that increase the risk for osteoporosis in both men and women include:

• Having a family history of osteoporosis. If your mother, father, or a sibling has been diagnosed with osteoporosis or has experienced broken bones from a minor injury, you are more likely to develop osteoporosis.
• Lifestyle factors. These include:
  • Smoking. People who smoke lose bone density faster than nonsmokers.
  • Alcohol use. Heavy alcohol use can decrease bone formation, and it increases the risk of falling. However, moderate alcohol use has been linked to higher bone density. Most doctors recommend limiting, but not eliminating, alcohol use.²
  • Getting little or no exercise. Weight-bearing exercises-such as walking, jogging, stair climbing, dancing, or lifting weights-keep bones strong and healthy by working the muscles and bones against gravity. Exercise may improve your balance and decrease your risk of falling.
  • Being small-framed or thin. People with small frames are more likely to develop osteoporosis because they have smaller bones and less bone mass. Thin people are more likely to develop osteoporosis because they have less body fat. Fat cells make estrogen, which may protect women from bone loss after menopause. However, being overweight puts women at risk for other serious medical conditions, including type 2 diabetes, high blood pressure, and coronary artery disease (CAD). For more information, see the topic Healthy Weight.
  • A diet low in foods containing calcium, phosphorus, and vitamin D.
• Having certain medical conditions. Some medical conditions, such as hyperthyroidism or hyperparathyroidism, put you at greater risk for osteoporosis.
• Taking certain medications. Several medications cause bone thinning, such as:
  • Corticosteroids, used to treat conditions such as asthma and chronic obstructive pulmonary disease (COPD). If used for a period of 6 months or longer, corticosteroids can lead to steroid-induced osteoporosis.³ Many men who develop osteoporosis do so as a result of using corticosteroids.
  • Medications used to treat endometriosis.
  • Aromatase inhibitors, used to treat breast cancer.
  • Thyroid replacement medication, if the dose is more than the body needs. This should be monitored by checking the level of thyroid-stimulating hormone (TSH) every year.
  • Depo-Provera, a birth control medication given by injection, if used for a long time.
  • Antacids that contain aluminum, if they are overused. Aluminum-containing antacids remove phosphorus and calcium from your body.
  • Anticonvulsant medications such as carbamazepine.⁴
• Having certain surgeries, such as having your ovaries removed before menopause.

Other risk factors for osteoporosis may include:

• Being of European and Asian ancestry, the people most likely to have osteoporosis. People of African ancestry are least likely.
• Being inactive or bedridden for long periods of time.
• Excessive dieting or having an eating disorder, such as anorexia nervosa.
• Being a female athlete, if you have infrequent menstrual cycles due to low body fat.

Women who have completed menopause have the greatest risk for osteoporosis, because their levels of the estrogen hormone drop. Estrogen protects women from bone loss. Likewise, women who no longer have menstrual periods-either because their ovaries are not working properly, or because their ovaries have been surgically removed-also can have decreased estrogen levels.

Citations

1. Anderson JJB (2004). Nutrition and bone health. In LK Mahan, S Escott-Stump, eds., Krause's Food, Nutrition, and Diet Therapy, pp. 642–666. Philadelphia: Elsevier.

2. Nieves J (2002). Nutrition. In SR Cummings et al., eds., Osteoporosis: An Evidence-Based Guide to Prevention and Management, pp. 85–108. Philadelphia: American College of Physicians–American Society of Internal Medicine.

3. American College of Rheumatology (2001). Recommendations for the prevention and treatment of glucocorticoid-induced osteoporosis. Arthritis and Rheumatism, 44(7): 1496–1503.

4. Ensrud KE, et al. (2004). Antiepileptic drug use increases rates of bone loss in older women. Neurology, 62(11): 2051–2057.