JAMA news releases are made available to the public after 3 pm US Central time on the first 4 Tuesdays of each month. The Archives of Journals news releases are made available to the public after 3 pm Central time on Mondays. We also provide a list of previous news releases.
THIS WEEK'S CONTENTS
ARCHIVES OF INTERNAL MEDICINE NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, January 28, 2008)
SEDENTARY LIFESTYLES ASSOCIATED WITH ACCELERATED AGING PROCESS
SNORERS APPEAR MORE LIKELY TO DEVELOP CHRONIC BRONCHITIS
PARTICIPANTS IN STUDIES USED AS BASIS FOR MEDICARE COVERAGE DECISIONS DIFFER FROM MEDICARE POPULATION
STUDY FINDS INCREASING RATES OF DIABETES AMONG OLDER AMERICANS
DIURETICS APPEAR COMPARABLE TO OR BETTER THAN OTHER DRUGS FOR TREATING HYPERTENSION IN PATIENTS WITH METABOLIC SYNDROME
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, January 28, 2008
Media Advisory: To contact corresponding author Tim D. Spector, M.D., F.R.C.P., e-mail: tim.spector{at}kcl.ac.uk. To contact editorialist Jack M. Guralnik, M.D., Ph.D., call Vicky Cahan at 301-496-1752.
SEDENTARY LIFESTYLES ASSOCIATED WITH ACCELERATED AGING PROCESS
CHICAGO—Individuals who are physically active during their leisure time appear to be biologically younger than those with sedentary lifestyles, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Regular exercisers have lower rates of cardiovascular disease, type 2 diabetes, cancer, high blood pressure, obesity and osteoporosis, according to background information in the article. “A sedentary lifestyle increases the propensity to aging-related disease and premature death,” the authors write. “Inactivity may diminish life expectancy not only by predisposing to aging-related diseases but also because it may influence the aging process itself.”
Lynn F. Cherkas, Ph.D., of King’s College London, and colleagues studied 2,401 white twins, administering questionnaires on physical activity level, smoking habits and socioeconomic status. The participants also provided a blood sample from which DNA was extracted. The researchers examined the length of telomeres—repeated sequences at the end of chromosomes—in the twins’ white blood cells (leukocytes). Leukocyte telomeres progressively shorten over time and may serve as a marker of biological age.
Telomere length decreased with age, with an average loss of 21 nucleotides (structural units) per year. Men and women who were less physically active in their leisure time had shorter leukocyte telomeres than those who were more active. “Such a relationship between leukocyte telomere length and physical activity level remained significant after adjustment for body mass index, smoking, socioeconomic status and physical activity at work,” the authors write. “The mean difference in leukocyte telomere length between the most active [who performed an average of 199 minutes of physical activity per week] and least active [16 minutes of physical activity per week] subjects was 200 nucleotides, which means that the most active subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average.” A sub-analysis comparing pairs in which twins had different levels of physical activity showed similar results.
Oxidative stress—damage caused to cells by exposure to oxygen—and inflammation are likely mechanisms by which sedentary lifestyles shorten telomeres, the authors suggest. In addition, perceived stress levels have been linked to telomere length. Physical activity may reduce psychological stress, thus mitigating its effect on telomeres and the aging process.
“The U.S. guidelines recommend that 30 minutes of moderate-intensity physical activity at least five days a week can have significant health benefits,” the authors write. “Our results underscore the vital importance of these guidelines. They show that adults who partake in regular physical activity are biologically younger than sedentary individuals. This conclusion provides a powerful message that could be used by clinicians to promote the potential anti-aging effect of regular exercise.”
(Arch Intern Med. 2008;168[2]:154-158. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: This study was supported in part by a grant from the Welcome Trust, grants from the National Institutes of Health and a grant from The Healthcare Foundation of New Jersey. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
EDITORIAL: MORE RESEARCH NEEDED TO VERIFY EXERCISE—AGING LINK
Additional work needs to be done to show a direct relationship between aging and physical activity, writes Jack M. Guralnik, M.D., Ph.D., of the National Institute on Aging, Bethesda, Md., in an accompanying editorial.
“Persons who exercise are different from sedentary persons in many ways, and although certain variables were adjusted for in this analysis, many additional factors could be responsible for the biological differences between active and sedentary persons, a situation referred to by epidemiologists as residual confounding,” Dr. Guralnik writes. “Nevertheless, this article serves as one of many pieces of evidence that telomere length might be targeted in studying aging outcomes.”
(Arch Intern Med. 2008;168[2]:131-132. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: This study was supported by the Intramural Research Program, National Institute on Aging, National Institutes of Health. Please see the article for additional information, including 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, January 28, 2008
Media Advisory: To contact corresponding author Chol Shin, M.D., Ph.D., e-mail: shinchol{at}pol.net.
SNORERS APPEAR MORE LIKELY TO DEVELOP CHRONIC BRONCHITIS
CHICAGO—Frequent snoring appears to be associated with the development of chronic bronchitis, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Chronic bronchitis involves inflammation of the lower airways accompanied by a persistent cough and the production of mucus or phlegm, according to background information and the article. Snoring appears more common among individuals with bronchitis.
Inkyung Baik, Ph.D., of the Korea University Ansan Hospital, Ansan, Republic of Korea, and colleagues studied 4,270 individuals (52 percent men and 48 percent women) starting in 2001 to 2003. At the beginning of the study, participants provided information on demographics, health conditions, family disease history and lifestyle, as well as details about how often they snored. Every two years through 2006, participants were re-interviewed and were classified as developing chronic bronchitis if they reported having a cough and sputum (phlegm produced during cough) on most days for at least three months per year for at least two years but did not have an asthma diagnosis.
During four years of follow-up, 314 individuals developed chronic bronchitis. After adjusting for age, smoking and other bronchitis risk factors, individuals who snored regularly were more likely to develop bronchitis than those who did not. Compared with those who never snored, individuals who snored five times times per week or less were 25 percent more likely and those who snored six to seven times per week were 68 percent more likely to develop bronchitis. The association was strongest in individuals who had never smoked, who worked in the home or who were overweight.
“The mechanisms underlying the association between snoring and chronic bronchitis are largely unknown,” the authors write. “It has been suggested that structural or functional changes in the airway due to inflammation may cause snoring and obstructive sleep apnea syndrome. Conversely, repeated snoring vibrations may act as mechanical stresses, leading to increased inflammatory response in the upper airway.”
“Further investigations are needed to confirm the association between snoring and chronic bronchitis and to explore the mechanisms underlying the association,” they conclude.
(Arch Intern Med. 2008;168[2]:167-173. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported by a grant from the Korea Centers for Disease Control and Prevention and by the Japan Society for the Promotion of Science. 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, January 28, 2008
Media Advisory: To contact corresponding author Rita F. Redberg, M.D., M.Sc., call Lauren Hammit at 415-502-9553. To contact corresponding author Noel S. Weiss, M.D., Dr.P.H., call Clare Hagerty at 206-685-1323.
PARTICIPANTS IN STUDIES USED AS BASIS FOR MEDICARE COVERAGE DECISIONS DIFFER FROM MEDICARE POPULATION
CHICAGO—The clinical trials used by Medicare for making decisions about coverage for cardiovascular products or services include participants who differ from Medicare beneficiaries in age, sex and country of residence, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Cardiovascular disease is the leading cause of death and disability among Medicare beneficiaries, according to background information in the article; expenses for this condition exceed those for any other. “Because Medicare expenditures continue to increase rapidly, it is necessary that coverage decisions be based on data most likely to maximize value and optimize outcomes for Medicare beneficiaries,” the authors write. An independent panel of physicians and other professionals advises the Centers for Medicare and Medicaid Services (CMS) on medical technologies. Panelists review technology assessments prepared for each new medical product or service and then vote on the quality of evidence for health benefits.
Sanket S. Dhruva, B.A., and Rita F. Redberg, M.D., M.Sc., of the University of California at San Francisco School of Medicine performed a meta-analysis of all trials included in technology assessments considered by the CMS advisory panel between 1998 and 2006. For the panel’s six meetings, 141 studies with a total of 40,009 participants were analyzed.
Compared with Medicare beneficiaries, clinical trial participants were an average of 60.1 years vs. 74.7, 75.4 percent vs. 41.8 percent male and 60 percent vs. zero lived in countries outside the United States. “The trials are conducted mostly in younger, healthier, male, non–U.S. populations,” the authors write. “Medicare beneficiaries, on the other hand, are mostly older women with comorbid [co-occurring] conditions. The clinical trials primarily relied on to inform national coverage decisions simply do not reflect the Medicare patient population. Compounding this problem, data frequently are not reported by age, sex and race.”
Elderly people and women are the most likely to be affected by these disparities and should be included in more clinical trials, the authors note. “The Food and Drug Administration already requests sex-specific data for new drug applications; it certainly would be consistent, and logical, for the CMS to require direct evidence of benefit in the coverage process. Alternatively, the CMS could issue a coverage decision with a requirement that continued coverage after a specified period depends on additional subgroup data, a variation of the newly introduced ‘coverage with evidence development’ initiative,” they write. “Closer linkage of evidence to coverage would promote better value and improved outcomes for the rapidly growing and underrepresented population of Medicare beneficiaries.”
(Arch Intern Med. 2008;168[2]:136-140. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported by a University of California at San Francisco Dean’s Summer Research Fellowship and by a Robert Wood Johnson Health Policy Fellowship. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
COMMENTARY: CLINICAL TRIAL RESULTS CANNOT ALWAYS BE GENERALIZED
The results of randomized clinical trials are most directly applied to populations of patients similar to those who participated in the study, write Noel S. Weiss, M.D., Dr.P.H., and colleagues at the University of Washington, Seattle, in an accompanying commentary.
“However, as Dhruva and Redberg illustrate in this issue of the Archives, the demographic profile of a trial’s participants and the medical care environment in which the trial is conducted may differ considerably from the target population and practice context in which the trial’s findings are later used to guide clinical decision making and policy,” the authors write.
“Although the measured effect of a particular therapy on a health outcome in the study population included in a given trial will, in many instances, closely reflect the effect of that intervention on the corresponding outcome in other settings, this extrapolation should not be made reflexively,” they conclude.
(Arch Intern Med. 2008;168[2]:133-135. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: 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, January 28, 2008
Media Advisory: To contact Frank A. Sloan, Ph.D., call Michelle Gailiun at 919-660-1306.
STUDY FINDS INCREASING RATES OF DIABETES AMONG OLDER AMERICANS
CHICAGO—The annual number of Americans older than 65 newly diagnosed with diabetes increased by 23 percent between 1994 to 1995 and 2003 to 2004, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
“The prevalence of diabetes mellitus is increasing, in part because of population aging, but also in younger persons,” according to background information in the article. The high rate of existing diabetes also contributes to a high rate of diabetes-related complications and premature death. “Awareness of the importance of active monitoring and management of diabetes has become more widespread; however, adherence to recommended practices remains low.”
Frank A. Sloan, Ph.D., and colleagues at the Duke University Medical Center, Durham, North Carolina, and colleagues analyzed Medicare program data for patients first diagnosed with diabetes during 1994 (33,164 patients), 1999 (31,722 patients) and 2003 (40,058 patients). This data was compared with that of two control groups consisting of individuals without the disease who were of similar race and ethnicity to those with diabetes. Death and complications of diabetes such as cardiovascular, cerebrovascular (damage to blood cells in the brain), ophthalmic (eye), renal (kidney) and lower extremity events were recorded.
“The annual incidence of diabetes increased by 23 percent between 1994 to 1995 and 2003 to 2004, and prevalence increased by 62 percent,” the authors write. After diagnosis, the death rate in patients having diabetes decreased by 8.3 percent when compared with those who were not diagnosed with the disease.
Most patients with diabetes experienced at least one complication within the next six years; for example, almost half had congestive heart failure. “Complication rates among persons diagnosed as having diabetes generally increased or stayed the same compared with those in the control groups during 1994 to 2004 except for ophthalmic diseases associated with diabetes,” the authors note. “In some cases, most notably renal events, including the most serious complications, there were increases in prevalence in both the diabetes and control groups.”
“Overall, our findings emphasize the overwhelming burden of diabetes, including the near 90 percent prevalence of an adverse outcome and many serious and resource-consuming outcomes such as coronary heart failure, myocardial infarction [heart attack] and stroke,” the authors conclude. “The burden of financing and providing medical care for persons older than 65 in the United States having diagnosed diabetes is growing rapidly as a result of increased incidence and, especially, prevalence of diagnosed diabetes, decreased mortality and overall lack of improvement in rates of complications in persons having diagnosed diabetes.”
(Arch Intern Med. 2008;168[2]:192-199. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported by a grant from the National Institutes of Aging. 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, January 28, 2008
Media Advisory: To contact Jackson T. Wright Jr., M.D., Ph.D., call Alicia Reale at 216-844-3825.
DIURETICS APPEAR COMPARABLE TO OR BETTER THAN OTHER DRUGS FOR TREATING HYPERTENSION IN PATIENTS WITH METABOLIC SYNDROME
CHICAGO—Use of calcium-channel blockers, alpha-blockers or angiotensin-converting enzyme (ACE) inhibitors appears to offer no advantages in improving clinical outcomes compared with use of diuretics when treating hypertension among individuals with metabolic syndrome, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. This appears particularly true for black patients.
Patients with hypertension (high blood pressure) and metabolic syndrome are at high risk for the complications of cardiovascular disease, according to background information in the article. The metabolic syndrome was defined as hypertension plus at least two of the following factors: diabetes or pre-diabetes; a body mass index (BMI) of at least 30; high triglyceride levels; or low levels of high-density lipoprotein (“good” cholesterol). Because some medications for high blood pressure (including alpha-blockers, ACE inhibitors and calcium channel blockers) have a favorable metabolic profile—for instance, have more favorable short-term effects on blood glucose or blood cholesterol levels—they have been advocated over other drugs (beta-blockers and diuretics) for the treatment of patients with metabolic syndrome.
Jackson T. Wright Jr., M.D., Ph.D., of Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, and colleagues analyzed data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). A total of 42,418 participants with hypertension and at least one other risk factor for cardiovascular disease were randomly assigned to take a diuretic (chlorthalidone, 15,255 patients), a calcium channel blocker (amlodipine besylate, 9,048 patients), an alpha-blocker (doxazosin mesylate, 9,061 patients) or an ACE inhibitor (lisinopril, 9,054 patients). Each drug was used to start treatment and other drugs could be added if necessary to control blood pressure. Patients were followed for an average of 4.9 years for all drugs except the alpha-blocker; that arm of the trial was discontinued after an average 3.2 years of follow-up in light of increased rates of cardiovascular disease, including a near two-fold increased rates of heart failure, when compared with the diuretic arm. A total of 23,077 ALLHAT participants (54.4 percent) met criteria for metabolic syndrome.
“No differences were noted among the four treatment groups, regardless of race or metabolic syndrome status for the primary end point (non-fatal myocardial infarction [heart attack] and fatal coronary heart disease),” the authors write. Among patients with the metabolic syndrome (7,327 black and 15,750 white patients), the calcium channel blocker, ACE inhibitor and alpha-blocker had higher rates of heart failure compared with the diuretic; the ACE inhibitor and the alpha-blocker also had an increased risk of combined cardiovascular disease.
“The lack of benefit of the agents with the most favorable metabolic profile (i.e., ACE inhibitors and alpha-blockers) was especially marked in the black participants with metabolic syndrome,” the authors write. “The magnitude of the excess risk of end-stage renal [kidney] disease (70 percent), heart failure (49 percent) and stroke (37 percent) and the increased risk of combined cardiovascular disease and combined coronary heart disease strongly argue against the preference of ACE inhibitors over diuretics as the initial therapy in black patients with metabolic syndrome. Similar higher risk was noted for those randomized to the alpha-blocker vs. the diuretic.”
“These findings fail to provide support for the selection of alpha-blockers, ACE inhibitors, or calcium channel blockers over thiazide-type diuretics to prevent cardiovascular or renal outcomes in patients with metabolic syndrome, despite their more favorable metabolic profiles,” the authors conclude.
(Arch Intern Med. 2008;168[2]:207-217. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported by a contract from the National Heart, Lung, and Blood Institute and by Pfizer Inc. (ALLHAT). 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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