Hazards of hip fractures

Hip fractures are a serious and significant health hazard. In the United States, for example, about one-fourth of people age 50 and over who suffer a hip fracture die within a year. Numerous others, ambulatory before a hip fracture, require long-term care afterward. Research findings appearing in a recent issue of the American Journal of Epidemiology, however, lend hope that regularly engaging in physical activity can reduce the risk of hip fracture.

The researchers combined data collected from three large long-term studies conducted in the Copenhagen, Denmark area between 1964 and 1992. In all, results from baseline and follow-up questionnaires obtained from 30,228 men and women were used. Included in the information collected was a self-report of leisure time physical activity engaged in by the volunteers.

Based on their level of physical activity, the participants were sorted into three groups: sedentary; moderately physically active 2 to 4 hours per week; and moderately physically active 4 or more hours per week or energetically physically active 2 to 4 hours per week. (Moderate physical activity was defined as performing activities such as light housekeeping or gardening, biking, or walking.)

Moderate physical activity lowers risk

The researchers tracked the participants by using hospital records to identify those volunteers who experienced a hip fracture. They then looked at the number of hip fractures that occurred within each of the three activity levels. After accounting for factors such as poor health, physical activity at work, smoking, alcohol intake, and weight that could also affect the risk of hip fracture, they found that women who reported at least two to four hours of moderate activity a week were about 28% less likely to suffer a hip fracture than those who were sedentary. The effect was less pronounced in men, but active men still fared better than their sedentary counterparts.

The effect of activity changes over time

The researchers also examined information from participants who had increased or decreased their level of physical activity between their baseline and follow-up interviews. Those participants who reduced their level of physical activity from either of the higher groups to the sedentary level, had about a 50% greater risk of hip fracture as those who maintained their level of physical activity.

Small, steady efforts rewarded

This study implies that a relatively modest but sustained investment of time and energy can reduce the risk of hip fracture. Less than half an hour a day of activity was needed to see benefits. While activity can be a formal exercise program, it can also encompass everyday life. Walking the dog, playing in the park with the grandchildren, hanging laundry, or catching up on yard work are all effective ways to maintain activity and lower the risk of hip fracture.