Breaking News: Activity Lowers Hip Fracture Risk in Older Women
Breaking News: Activity Lowers Hip Fracture Risk in Older Women
ABSTRACT & COMMENTARY
Synopsis: Women 65 years of age and older who had an active lifestyle had a reduced risk of hip fracture in comparison to women who reported less physical activity in their lives. Self-reported activity levels did not correlate with the incidence of vertebral or wrist fractures.
Source: Gregg EW, et al. Ann Intern Med 1998;129:81-88.
Increasing empathy for patients with musculoskeletal problems was developing while making the descent from Mt. Khathadin, the highest peak in the state of Maine. After 10 hours on the trail, muscles were no longer responding as they should, and each step required premeditation to avoid a fall on the rocky path. Just as serious doubts were arising about reaching the end the trailhead before nightfall, a group of four women, each at least in her seventh decade, passed by.
Mountain climbing was not an activity about which Gregg and colleagues specifically asked in their study of the relationship between physical activity and fracture risk in older women. They enrolled 9704 women aged 65 year or older and assessed their level of physical activity in the preceding year by questionnaire. Their subjects-community-dwelling women, all of whom could ambulate independently-were assigned to quintiles of activity based upon the total number of kilocalories expended per week. Possible confounding factors were also assessed, including self-reported diseases such as diabetes, hypertension, stroke, and arthritis; osteoporosis-associated items including alcohol consumption, cigarette smoking, estrogen hormone use, and calcium ingestion; and bone mineral density of the calcaneus and the distal radius. Body height and weight, level of function, and use of benzodiazepines were also recorded. The women were contacted at four-month intervals for a mean of 7.6 years. Baseline and follow-up lateral spine radiographs were obtained in 7238 women, with the follow-up study performed a mean of 3.7 years after enrollment. Self-reported hip fractures were confirmed by review of radiographs or radiographic reports.
After segregating the subjects into quintiles based upon activity, it was apparent that many of the possible osteoporosis-related and other health and function factors clustered together. The least active quintile of subjects was significantly older, heavier, used more alcohol and cigarettes, reported more difficulty walking, and reported fair or poor health more often than the most active group. Calcaneal and radial bone mineral density were not significantly different among the five groups. The incidence of vertebral fractures was not significantly different among the groups. There was a trend toward increased frequency of wrist fractures with increasing activity. The trend in reduced hip fracture incidence is statistically significant even after adjustment for other risk factors. In a multivariate model, the quintile with the highest activity level had an adjusted relative risk of 0.64 for hip fracture vs. the lowest activity quintile. No trends for wrist or vertebral fracture were found in association with overall activity level. The risk of vertebral compression fractures was reduced in women who reported participating in moderate-to-vigorous sports or recreational activities such as aerobic dance or tennis. The multivariate adjusted relative risk for vertebral fracture was 0.67 (95% confidence limits 0.49-0.94).
COMMENT BY JERRY M. GREENE, MD
This study provides another good reason to recommend regular exercise as part of a healthy lifestyle, especially for older women. Gregg et al do not answer the interesting question of why women who are more active have fewer hip fractures. While it is possible that higher levels of activity are correlated with increased bone mineral density of the hip, this was not directly measured. A speculation that the authors discuss is that increased activity translates into more agility; that is, more active women are more likely to break a fall without breaking a hip. The risk of falling does not seem to be a key factor since 12% of the least active group reported two or more falls in the preceding year, while nearly the same percentage, 11.9%, of those in the most active group reported falling that often. Regardless of the mechanism, the more active group had a lower relative risk of hip fracture.
It is important to note that this was not an intervention study but one of natural history. An intervention study of exercise for patients with osteoarthritis had a large number of subjects stop exercising despite regular contact and encouragement to continue an exercise regimen.1 Promoting an active lifestyle is a life-long process, but bringing the news about reducing hip fracture risk to aging women may help some of them break the habit of inactivity-before they break something else.
Reference
1. Ettinger WH, et al. JAMA 1997;277:25-31.
Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.