History of fracture is the single most important factor for evaluating the risk of fractures in postmenopausal women, say the authors of a recent study published in Archives of Internal Medicine . But traditionally, only fractures occurring after menopause have been considered a risk factor for osteoporosis and subsequent postmenopausal fractures. In this recent Archives study, women who sustained a fracture (unrelated to a motor vehicle accident) between the ages of 20 and 50 were more likely to sustain a fracture after menopause.

About the study

Researchers at the University of Auckland in New Zealand recruited 1284 women who were 10 or more years postmenopausal (average age 73). These women were able to walk independently and had no disorders of calcium metabolism; no kidney, thyroid, or liver disfunction; and no systemic illnesses. In the previous year, these women had not taken hormone replacement therapy or any drugs known to affect bone or calcium metabolism.

Each woman answered a questionnaire about her medical, menstrual, smoking, alcohol, and fracture history. Fractures were classified according to when they occurred: before age 20, between ages 20 and 50, or after age 50. In addition, height and weight were measured and bone mineral density was tested using dual-energy x-ray absorptiometry (DEXA). Fractures resulting from motor vehicle accidents and information from three women who experienced premature menopause before age 40 were excluded from the study analysis.

The researchers looked at which women had fractures before the age of 50, which women had fractures after the age of 50, and which women had both.

The findings

Women who sustained fractures between the ages of 20 and 50 were 74% more likely to have a fracture after age 50 than women with no fractures between ages 20 and 50. After the researchers accounted for known risk factors for postmenopausal fractures (i.e., bone density, age, mother's history of hip fracture, smoking, etc.), the risk for women with fractures between ages 20 and 50 was 83% higher than for women without such fractures.

The findings of this study suggest that fractures occurring in early adulthood may be predictors of future osteoporosis and subsequent postmenopausal fractures.

There are limitations to this study that are worth noting. First, the researchers looked at the questionnaires and described an apparent relationship between fractures in early adulthood and fractures after age 50. What we don't know is if fractures in early adulthood were a sign of low bone density that would eventually lead to osteoporosis, or if early-adulthood fractures weakened the bones, thus putting the women at risk for later fractures. Second, the information on medical, menstrual, smoking, alcohol, and fracture history was self-reported by the women. Because the women were asked to recall events from some time in the past, the accuracy of the information they provided may have been compromised. Finally, some minor fractures (of the hand or foot bones, for example) go unnoticed and would therefore not be accounted for in this study.

How does this affect you?

If you break your ankle at age 30, are you at increased risk for osteoporosis and related fractures after menopause? Possibly. The findings of this study merely point out that the women who had fractures in early adulthood were more likely to have fractures after menopause than women who did not have fractures in early adulthood.

Based on these findings, the authors of the study suggest that doctors ask their female patients about fractures in early adulthood as well as late adulthood, and consider these fractures when deciding whether to recommend bone density testing or postmenopausal bone-building therapies. In addition, they suggest that younger women who sustain fractures consider making changes to reduce their risk of osteoporosis—such as eating adequate amounts of calcium and vitamin D, quitting smoking, drinking only moderate amounts of alcohol and caffeine, and exercising regularly.