Risk Factors

Risk Factors

Gender. An estimated 10 million adults in the United States have osteoporosis and another 34 million have low bone mass that places them at risk for developing osteoporosis. A 2004 report from the Surgeon General's office estimates that by 2020, half of all Americans over age 50 could be at risk for this condition. Eighty percent of people with osteoporosis are women. Men start with higher bone density and lose calcium at a slower rate than women, which is why their risk is far lower. Nevertheless, after age 50, bone loss increases and, according to recent studies, more rapidly than previously thought.

Ethnicity. Although adults from all ethnic groups are susceptible to developing osteoporosis, Caucasian and Asian women and men face a comparatively greater risk. Approximately 20% of non-Hispanic white and Asian women older than age 50 have osteoporosis, and over 50% are at risk due to low bone mass. Osteoporosis affects 10% of Hispanic women (49% at risk) and 5% of non-Hispanic black women (35% at risk). Body type can also be a factor.Osteoporosis is more common in women who have a small, thin body frame and bone structure.

Specific Risk Factors for Estrogen Deficiency and Low Bone Density in Women

Events associated with estrogen deficiencies are the primary risk factors for osteoporosis in women.

Natural and Surgical Causes of Estrogen Deficiency.

• Menopause. Within 5 years after menopause, the risk for fracture increases dramatically. Fractures occurring during this period are more likely to occur in the wrist or spine than the hip, but their occurrence is a strong predictor of later severe osteoporosis and hip fracture.
• Surgical removal of ovaries.
• Missing periods for 3 months or longer.
• Never giving birth.
• Paradoxically, pregnancy and nursing do not increase the risk for osteoporosis even though during those times calcium is diverted from the mother to the baby. A factor believed to be associated with reduced bone density is elevated at a constant level during nursing, but as the baby is weaned, levels of the factor decline and bone formation is restored.