BONE HEALTH

Moderate physical activity may lower the risk of hip fractures.

* THE QUESTION how much physical activity is needed to reduce the risk of hip fractures?

* PAST STUDIES have shown that active adults have a 20 percent to 50 percent lower risk of hip fracture than sedentary ones. It is not clear, however, what level of physical activity is required to see such risk reduction.

* THIS STUDY examined the association between moderate levels of physical activity and the risk of hip fracture in 61,200 white, post-menopausal women during a 12-year period. Women who walked at a pace of 2 to 3 miles per hour for at least eight hours a week or who engaged in equivalent activity had a 55 percent lower risk of hip fracture than those who walked less than an hour a week. Even those who walked only four hours a week and did no other exercise had a 41 percent lower risk of fractures than the least active women.

* WHO MAY BE AFFECTED BY THESE FINDINGS? Post-menopausal women.

* CAVEATS The results may not apply to men and to other ethnic groups. In addition, the results are based on questionnaires. Finally, this was not a randomized trial.

* BOTTOM LINE Post-menopausal women may wish to consider at least four hours of walking a week, in consultation with their physician.

* FIND THIS STUDY Nov.13 issue of the Journal of the American Medical Association; abstract online at http://jama.ama-assn.org/.

AGING

Growth hormone supplements builds muscle but raises risks.

* THE QUESTION Do injections of growth hormone benefit older adults?

* PAST STUDIES have shown that certain hormone deficiencies in older people may lead to loss of muscle mass and strength and an increase in body fat. Researchers have theorized that supplementation may prevent some of these problems.

* THIS STUDY examined the effects of growth hormone (GH) injections for six months, with or without supplements of sex hormones (SH), in 74 men and 57 women aged 65 and older. The participants were randomly assigned to one of four groups, which received GH and SH (estrogen and progesterone for women, testosterone for men), GH and placebo SH, placebo GH and SH or placebo GH and placebo SH.

Those who took growth hormone in conjunction with sex hormones had the greatest increase in muscle mass -- an average of 4.3 kilos for the men and 2.1 kilos for the women, equivalent to the results produced by six months of exercise three times a week. People in this group also lost a significant amount of fat. Neither GH nor SH affected strength for women, but men taking GH plus testosterone experienced a marginal increase in strength. In addition, these men experienced increased endurance on a treadmill.

These benefits, however, were accompanied by a significant risk of side effects such as diabetes, swelling, carpal tunnel syndrome and joint pains.

* WHO MAY BE AFFECTED BY THESE FINDINGS? Men and women 65 and older.

* CAVEATS The results need to be verified in larger studies and for a longer time.

* BOTTOM LINE Older men and women may wish to refrain from taking growth hormone injections until more studies are done to determine their safety.

* FIND THIS STUDY Nov. 13 issue of the Journal of the American Medical Association; abstract online at http://jama.ama-assn.org/.

CANCER

Attitude does not appear to affect survival or recurrence.

* THE QUESTION Does a positive attitude increase a cancer patient's chances of recovery?

* PAST STUDIES have had conflicting results on the theory that a fighting spirit -- as opposed to hopelessness and denial -- may improve a person's odds of surviving cancer and avoiding a recurrence.

* THIS STUDY reviewed 28 studies of coping style and found fighting spirit to be associated with longer survival or reduced risk of recurrence only in smaller studies of fewer than 125 participants. The same was true for the link between helplessness or hopelessness and adverse effects on survival. Finally, larger studies found little evidence to support detrimental effects of anxious coping or beneficial effects of proactive coping.

* WHO MAY BE AFFECTED BY THESE FINDINGS? People with cancer and those in remission.

* CAVEATS The results are based on studies where baseline information may have been inconsistent or different confounding factors were considered. In addition, the pool of available studies may be subject to publication bias, where negative results are less likely than positive results to be published. Finally, more large studies are needed to assess the attitude theory.

* BOTTOM LINE Cancer patients and those in remission should feel free to adopt any coping style that does not interfere with their treatment. They do not need to worry about their attitude's affecting their chances of survival or recurrence.

* FIND THIS STUDY Nov. 9 issue of the British Medical Journal or www.bmj.com/content/vol325/issue7372/.

-- Haleh V. Samiei