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THIS WEEK'S CONTENTS
ARCHIVES OF INTERNAL MEDICINE NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, December 11, 2006)
HIGHER PHYSICAL ACTIVITY ASSOCIATED WITH REDUCED RISK OF BREAST CANCER
WEIGHT LOSS THROUGH CALORIE RESTRICTION, BUT NOT EXERCISE, MAY LEAD TO BONE LOSS
HEIGHT LOSS IN OLDER MEN ASSOCIATED WITH INCREASED RISK OF HEART DISEASE, DEATH
ARCHIVES OF OPHTHALMOLOGY NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, December 11, 2006)
MAJOR VISUAL DISORDERS IN PEOPLE OVER 40 MAY BE COSTING THE U.S. ECONOMY BILLIONS
ARCHIVES OF NEUROLOGY NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, December 11, 2006)
RECURRENCE OF SILENT BRAIN LESIONS AFTER INITIAL STROKE MAY PREDICT SUBSEQUENT STROKE
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, December 11, 2006
Media Advisory: To contact corresponding author James R. Cerhan, M.D., Ph.D., call Elizabeth Zimmerman at 507-266-0810.
HIGHER PHYSICAL ACTIVITY ASSOCIATED WITH REDUCED RISK OF BREAST CANCER
CHICAGO—Women with higher levels of physical activity may have a reduced risk of breast cancer after menopause, according to a report in the December 11/25 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. The association appears to be stronger for estrogen receptor positive/progesterone receptor negative tumors (which are typically more aggressive) than for other types of breast cancer tumors.
Breast cancer may be biologically heterogeneous, meaning that not all cases have the same causes or disease processes, according to background information in the article. One way cancers differ is by hormone receptor status. Tumors are classified as estrogen- and progesterone-receptor (ER/PR) positive or negative based on whether these hormones bind to the surface of the tumor. “Recent studies have found that various well-established risk factors for breast cancer vary by the ER/PR profile of the tumor, including age, menopausal status, parity, age at menarche, age at first pregnancy, hormonal use, family history, body mass index (BMI), waist-hip ratio, alcohol consumption, dietary fat intake and folate level,” the authors write.
Aditya Bardia, M.D., M.P.H., of the Mayo Clinic College of Medicine, Rochester, Minn., and colleagues reported findings from the Iowa Women’s Health Study, which includes 41,836 postmenopausal women who were age 55 to 69 in 1986. The women filled out a 16-page questionnaire at the beginning of the study that included information about how often and with what intensity they participated in physical activity during “free time.” High physical activity (9,111 women) was defined as vigorous activity (such as jogging, swimming or racket sports) two or more times per week or moderate activity (such as bowling, golf, gardening or walking) more than four times per week; medium physical activity (10,030 women) was defined as participation in vigorous activity once per week or moderate activity one to four times per week; and low physical activity included the rest of the women (17,222). Follow-up questionnaires were completed in 1987, 1989, 1992, 1997 and 2002. Information about breast cancer cases, including ER/PR status, was identified through the Iowa Cancer Registry.
Through 2003, 2,548 cases of breast cancer were observed in the 36,363 women who were included in this analysis. Women with high physical activity levels based on the original survey had a 14 percent lower risk of developing breast cancer than those with low physical activity levels. After the researchers adjusted for body mass index (BMI), those with high physical activity levels had a 9 percent lower risk of breast cancer, suggesting that some but not all of the association was due to the effect of exercise on body weight. The inverse association between high physical activity levels and lower risk of breast cancer was strongest for women with ER+/PR- tumors; after adjusting for BMI, women with high physical activity levels had a 34 percent lower risk of developing this type of cancer.
Physical activity reduces body fat, the major source of estrogen in postmenopausal women, the authors write. “Lowering estrogen levels could lead to a decreased ER+/PR+ tumors, the opposite of which is seen in obesity, in which increased circulating estrogens are associated with increased ER+/PR+ tumors. Consistent with this mechanism, the association of physical activity with ER+/PR+ tumors attenuated after adjustment for BMI.” Because adjusting for BMI did not change the risk of ER+/PR- tumors, it is possible that a different mechanism—such as certain growth factors that become more prevalent with exercise—may be involved in the association between physical activity and these tumors.
“Further studies are needed to confirm these novel findings, and to evaluate similar relationships among premenopausal women,” the authors conclude. “If found to be causally related to breast cancer, physical activity would have a substantial public health effect on the prevention of this disease, along with its other positive health benefits.”
(Arch Intern Med. 2006;166:2478-2483. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: This study was supported in part by a grant from the National Cancer Institute. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, December 11, 2006
Media Advisory: To contact Dennis T. Villareal, M.D., call Jim Dryden at 314-286-0110.
WEIGHT LOSS THROUGH CALORIE RESTRICTION, BUT NOT EXERCISE, MAY LEAD TO BONE LOSS
CHICAGO—Men and women who lose weight by cutting calories also may be losing bone density, but weight loss through exercise does not seem to produce the same effect, according to a report in the December 11/25 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Most U.S. adults are either overweight or obese, according to background information in the article. The primary treatment for these conditions is lifestyle modification, including exercise and low-calorie diets. However, decreasing body weight is associated with decreased bone mineral density, which increases the risk for osteoporosis (weakening of the bones) and hip fractures in older men and women.
Dennis T. Villareal, M.D., Washington University School of Medicine, St. Louis, and colleagues studied the effects of weight loss on bone loss in 48 adults (30 women and 18 men, with an average age of 57). Nineteen were assigned to follow a calorie-restricted diet (to decrease energy intake by 16 percent for three months, then by 20 percent for nine months), 19 to eat the same number of calories and begin an exercise program (to maintain energy intake, but increase energy expenditure by 16 percent for three months and 20 percent for nine months) and 10 to receive information on healthy lifestyles only when requested. All participants were weighed at the beginning of the study and again after one, three, six, nine and 12 months. Bone mineral density was measured every three months using a technique known as dual-energy x-ray absorptiometry. At the start of the study and after six months and 12 months, blood samples were taken to test for hormones and chemical markers that show whether bone tissue is being absorbed and regenerated.
Forty-six of the participants completed the study. After one year, those in the calorie restriction group lost an average of 8.2 kilograms or 18.1 pounds, those in the exercise intervention group lost 6.7 kilograms or 14.8 pounds and those in the healthy lifestyle group maintained their weight. Individuals in the calorie-restriction group also lost an average of 2.2 percent of their bone density in the lower spine, 2.2 percent at the hip and 2.1 percent at the top end of the femur—all high-risk fracture sites. There were no significant changes in bone mineral density in the exercise or healthy lifestyle groups. In both weight-loss groups, bone turnover—which occurs when old bone is broken down—increased, as indicated by the markers of bone turnover in the blood.
“A common explanation given for the bone loss induced by weight loss is reduction in mechanical stress on the weight-bearing skeleton (i.e., hip and spine),” the authors write. “Accordingly, the preservation of bone mineral density in the exercise group could be mediated through exercise-induced bone loading.” In addition, although both weight-loss groups experienced an increase in bone turnover, this was only detrimental to the calorie restriction group. Muscles pulling on bones during exercise is thought to produce strains in the skeleton that stimulate new bone production. “Our results are consistent with an osteoprotective effect of exercise-induced mechanical strain on the skeleton and consequent increase in bone turnover,” the authors continue.
“These findings have important implications in designing an appropriate weight-loss therapy program in middle-aged adults, particularly in the subset of patients who may already be at increased risk for bone fracture,” they conclude.
(Arch Intern Med. 2006;166:2502-2510. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This work was supported by grants from the National Institutes of Health. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, December 11, 2006
Media Advisory: To contact S. Goya Wannamethee, Ph.D., e-mail: goya{at}pcps.ucl.ac.uk.
HEIGHT LOSS IN OLDER MEN ASSOCIATED WITH INCREASED RISK OF HEART DISEASE, DEATH
CHICAGO—Men who lose 3 centimeters or more of height as they age have an increased risk of death and of coronary heart diseases events, according to a report in the December 11/25 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Changes in bone, muscles and joints typically lead men and women to become shorter as they age, according to background information in the article. Although a small amount of height loss is normal and probably not associated with any disease, more significant height loss may be a sign of osteoporosis (thinning of the bones). Substantial height loss can affect breathing and digestive functions, leading to poor eating habits and weight loss, and may be associated with sarcopenia, the loss of muscle mass.
S. Goya Wannamethee, Ph.D., Royal Free and University College Medical School, London, and colleagues studied 4,213 men who originally enrolled in the British Regional Heart Study between 1978 and 1980. Follow-up examinations were conducted 20 years later, when the men were 60 to 79 years old. At that time, the men completed a questionnaire providing details about their lifestyle and medical history. They were asked to describe their current health status—excellent, good, fair or poor—and whether their physician had ever told them they had cardiovascular disease or a number of other conditions. Participants’ height and weight were measured both at the beginning of the study and at the 20-year follow-up; they were monitored through 2004 to see if they had developed cardiovascular disease, and deaths were tracked through 2005.
Between the initial examination and the 20-year follow-up, the men lost an average of 1.67 centimeters of height. The researchers divided the participants into four groups based on how much their height changed: 1,471 lost less than 1 centimeter; 1,330 lost between 1 and 1.9 centimeters; 807 lost between 2 and 2.9 centimeters; and 605 were 3 centimeters shorter or more. During the average of five years that they were followed after that, 760 men died. Risk of death increased with height loss and was substantially higher in men who lost 3 centimeters or more—they were 64 percent more likely to die during the course of the study than those who lost less than 1 centimeter. Most of the additional deaths in men who had lost height were attributable to cardiovascular disease, respiratory disease or other non-cancer diseases. Height loss was also associated with an increased risk for coronary heart disease events, even after the researchers adjusted for prior cardiovascular disease and its known risk factors.
It is unclear exactly which mechanisms are responsible for the association between height loss, illness and death. Osteoporosis increases the risk of death and may play a role; however, it typically causes a loss of 6 centimeters or more of height. “The significantly increased risk of all-cause mortality in men with a height loss of 3 centimeters or more was observed even after exclusion of men with a height loss of 4 centimeters or more,” a total of 283 men, the authors write. “Thus, the increased mortality risk was already seen in men with a height loss in the range of 3 centimeters to 4 centimeters and was not solely attributable to extreme height loss.” There could also be an underlying mechanism that contributes to both bone loss, which leads to height loss, and coronary heart and other diseases.
(Arch Intern Med. 2006;166:2546-2552. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: The British Regional Heart Study is a British Heart Foundation Research Group and receives support from the Department of Health (England). Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, December 11, 2006
Media Advisory: To contact David B. Rein, Ph.D., call Lisa Bistreich at 919-316-3596.
MAJOR VISUAL DISORDERS IN PEOPLE OVER 40 MAY BE COSTING THE U.S. ECONOMY BILLIONS
CHICAGO—Major visual disorders in Americans older than 40 years may cost the U.S. economy an estimated $35.4 billion a year, according to a report in the December issue of Archives of Ophthalmology, one of the JAMA/Archives journals.
Millions of Americans have visual impairment, blindness or other eye diseases, according to background information in the article. These diseases include age-related macular degeneration (AMD), cataracts, diabetic retinopathy, primary open-angle glaucoma and refractive errors, which are correctable with glasses or contact lenses. In addition to direct medical costs, other direct costs, such as nursing home health care, are related to these major visual disorders. Productivity losses also occur when individuals with visual impairment cannot work or earn lower wages.
David B. Rein, Ph.D., of RTI International, Research Triangle Park, N.C., and colleagues analyzed the financial burden of eye diseases in 2004. The researchers used private insurance and Medicare claim data to approximate direct medical costs. Evidence from published sources provided information about other direct costs, consisting of nursing home care, government purchase programs and guide dogs for the blind. Data from a national survey about labor and income were used to estimate productivity losses.
Researchers found that major visual disorders cost the U.S. an estimated $16.2 billion in direct medical costs, $11.1 billion in other direct costs and $8 billion in productivity losses, bringing the total annual financial burden to an estimated $35.4 billion. The annual governmental budgetary impact, calculated by adding the portion of the financial burden estimate produced by the government to additional amounts of social welfare payments from the federal treasury to people with visual impairment and blindness, was found to be $13.7 billion.
Direct medical costs were estimated to be approximately $6.8 billion for cataracts, $5.5 billion for refractive error, $2.9 billion for glaucoma, $575 million for AMD and $493 million for diabetic retinopathy. The majority of direct medical costs included outpatient services and medications, while inpatient costs accounted for almost no costs. Refractive error made up the largest share of direct medical costs for those age 40 to 64 (46.2 percent), while cataracts accounted for the largest portion among patients 65 years and older (56.2 percent). “Increased overall costs for AMD and cataracts among patients aged 65 years and older were attributable to increased numbers of patients who use outpatient services for these conditions,” the authors write.
Many costs are expected to increase in the future as the American population ages, the authors note. “Public health efforts to screen for and treat currently undiagnosed disease may be likely to increase direct medical care costs, but if effective, they will also improve visual outcomes, and potentially reduce productivity losses and nursing home placements associated with visual impairment and blindness,” they conclude. “Technological advancements that lead to reductions in the unit costs of glasses, cataract surgery and medications to treat glaucoma have the potential to lead to substantial direct medical cost savings.”
(Arch Ophthalmol. 2006;124:1754-1760. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported by the Centers for Disease Control and Prevention’s Division of Diabetes Translation. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, December 11, 2006
Media Advisory: To contact corresponding author Steven Warach, M.D., Ph.D., call Margo Warren at 301-496-5924.
RECURRENCE OF SILENT BRAIN LESIONS AFTER INITIAL STROKE MAY PREDICT SUBSEQUENT STROKE
CHICAGO—Asymptomatic brain lesions that recur on brain scans within three months of a patient’s initial stroke may predict subsequent stroke, according to a report in the December issue of Archives of Neurology, one of the JAMA/Archives journals.
Previous studies have shown that silent (without symptoms) ischemic lesions—changes in tissue that occur when blood flow to an area of the brain is reduced or blocked—occur more frequently than symptomatic lesions up to three months after stroke, according to background information in the article. Based on this and other findings, researchers hypothesized that silent ischemic lesions on magnetic resonance imaging (MRI) may be a marker for subsequent strokes and other vascular events.
Dong-Wha Kang, M.D., Ph.D., of the National Institute of Neurological Disorders and Stroke, Bethesda, Md., and colleagues studied 120 patients who had an acute ischemic stroke between 2000 and 2002. Each patient had MRI performed within 24 hours of the stroke and on the fifth day after, and 68 underwent follow-up MRI after 30 or up to 90 days. In 2003, 104 of the patients or their caregivers were interviewed to determine if the patients had an additional stroke or had undergone related procedures.
Of these 104 patients, 50 were men and 54 were women, and the average age was 71.3. Silent ischemic lesions were observed on MRI in 42 (40.4 percent) of the patients, including in 35 (33.7 percent) after five days and in 15 (22.1 percent) of the 68 who had 30- or 90-day MRIs. At the 2003 follow-up, eight (7.7 percent) of the total 104 patients had a recurrent ischemic stroke; three (2.9 percent) had a transient ischemic attack (mini-stroke), a stroke with complete recovery within 24 hours; and three (2.9 percent) died from vascular causes during the study’s follow-up period. Patients with silent ischemic lesions on the 30- or 90-day MRI had about 6.5 times the odds of having a subsequent ischemic stroke, and those with silent lesions on any MRI had increased odds of death from vascular causes, recurrent ischemic stroke or transient ischemic attack.
“It is a matter of circumstance, rather than tissue pathological features, that determines whether cerebral ischemia is symptomatic or silent,” the authors write. “Clinical symptoms depend on the size, location and number of new lesions. Thus, we assume that the pathological process that causes silent lesion recurrence on MRI is the same as the process that causes clinical recurrent strokes. Magnetic resonance imaging may depict pathological changes before the development of clinical stroke symptoms.”
(Arch Neurol. 2006;63:1730-1733. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported by the Intramural Research Program of the National Institutes of Health, National Institute of Neurological Disorders and Stroke. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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