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June 23, 2009JAMA 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
JAMA NEWS RELEASES
(Embargoed for Release: 3 p.m. CT Tuesday, June 23, 2009)
JAMA REPORT (VIDEO SCRIPT)
INFORMATION CONTAINED IN THESE NEWS RELEASES IS PROTECTED BY COPYRIGHT. JOURNAL ATTRIBUTION IS REQUIRED. JOURNALISTS CAN NOW ACCESS EMBARGOED JAMA/ARCHIVES STUDIES ON-LINE. Go to www.jamamedia.org for more information and to apply for access. TV Note: This week's JAMA Report video is on the association between body weight and risk of pancreatic cancer. The report will be fed Tuesday, June 23, from 9:00 - 9:30 a.m. ET and 2:00 - 2:30 p.m. ET, on Galaxy 28 (C-Band), Transponder 19, downlink frequency: 4080 vertical, audio 6.2/6.8. For more information, call 312/464-JAMA. Please Note: The FOR THE MEDIA website now has a search feature to enable media to find previous JAMA/Archives news releases on specific medical topics. This search feature link is located on the home page at www.jamamedia.org EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), Tuesday, June 23, 2009
Being Overweight, Obese During Early Adulthood Associated With Greater Risk of Pancreatic Cancer
CHICAGO—Young adults who are overweight or obese have an increased risk of pancreatic cancer, and being obese at an older age is associated with a lower overall survival rate for patients with pancreatic cancer, according to a study in the June 24 issue of JAMA. Pancreatic cancer is the fourth leading cause of cancer-related death for both men and women in the United States. As the prevalence of overweight and obesity have rapidly increased during the last 2 decades, accumulating evidence has emerged that excess body weight is a risk factor for pancreatic cancer. "However, to our knowledge, no study has explicitly reported the association between excess body weight across an individual's life span and the risk of pancreatic cancer or identified at which ages the key predisposing weight change usually occurs," the authors write. Donghui Li, Ph.D., of the University of Texas M. D. Anderson Cancer Center, Houston, and colleagues conducted a study to determine the associations between body mass index (BMI) over a lifetime and pancreatic cancer risk, age at onset, and overall patient survival. The study included 841 patients with pancreatic cancer and 754 healthy individuals matched by age, race, and sex. Height and body weight histories were collected by personal interview starting at ages 14 to 19 years and over 10-year intervals progressing to the year prior to recruitment in the study. The researchers found that individuals who were overweight (a BMI of 25-29.9) from the ages of 14 to 39 years or obese (a BMI of 30 or greater) from the ages of 20 to 49 years had an associated increased risk of pancreatic cancer, independent of diabetes status. The association between average BMI (per 5-unit increase) and risk of pancreatic cancer was stronger in men than in women. The association was statistically significant for each age group from 14 to 69 years in men but only from ages 14 to 39 years in women. The estimated association of average BMI (per 5-unit increase) with cancer risk also was slightly stronger in ever smokers than in never smokers. It was estimated that 10.3 percent of never smokers and 21.3 percent of ever smokers had pancreatic cancer attributable to being overweight or obese at an early age prior to cancer diagnosis (i.e., from the ages of 14-59 years). Individuals who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 to 6 years (median [midpoint] age of onset was 64 years for patients with normal weight, 61 years for overweight patients, and 59 years for obese patients). Compared with those with normal body weight and after adjusting for all clinical factors, individuals who were overweight or obese from the ages of 30 to 79 years or in the year prior to recruitment had reduced overall survival of pancreatic cancer regardless of disease stage and tumor resection status.
"While our observations require confirmation, they provide support for a role of excess body weight in the development and progression of pancreatic cancer," the authors conclude.
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. Editorial: Overweight, Obesity, and Pancreatic Cancer — Beyond Risk Alone
In an accompanying editorial, Robert R. McWilliams, M.D., and Gloria M. Petersen, Ph.D., of Mayo Clinic, Rochester, Minn., comment on the findings regarding BMI and risk of pancreatic cancer.
"The study by Li et al represents an incremental advance in the understanding of clinical factors contributing to pancreatic cancer development and progression. In particular, the survival analyses illustrate how epidemiological studies that include retrospective information gathering, combined with prospective follow-up, are helpful in establishing survival factors outside of the clinical trial setting. The biological bases for how overweight and obesity contribute to younger age of diagnosis, increased risk for pancreatic cancer, and poorer survival in pancreatic cancer require further investigation. Understanding these associations will provide much needed clues for targeting potential preventive and therapeutic strategies for this extremely aggressive and resistant type of cancer."
Editor's Note: Please see the article for additional information, including 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. EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), Tuesday, June 23, 2009
Migraines With Aura in Midlife Associated With Increased Prevalence of Brain Lesions in Older Age
CHICAGO—Middle-aged women who had migraine headaches with aura (sensory disturbances, such as with vision, balance or speech) had a higher prevalence of brain lesions when they were older, compared to individuals without similar types of headaches, according to a study in the June 24 issue of JAMA. Migraine is a common neurovascular disorder that affects approximately 11 percent of adults and is more common in women than men. Approximately one-third of individuals with migraine experience neurological aura symptoms before headache onset (migraine with aura). Migraine is considered to be an episodic condition with no long-term consequences. However, recent studies suggest that migraine attacks may be associated with brain lesions identified on magnetic resonance imaging (MRI), particularly in the cerebellum, according to background information in the article. Ann I. Scher, Ph.D., of Uniformed Services University, Bethesda, Md., and colleagues examined the relationship of midlife migraine symptoms and late-life infarct (tissue death)-like lesions evident on MRI. The study included 4,689 men and women in Reykjavik, Iceland (born between 1907-1935; 57 percent women) who were followed-up since 1967, examined, and interviewed about migraine symptoms in midlife (average age, 51 years; range, 33-65 years). Between 2002 and 2006, more than 26 years later, brain MRIs were performed. Participants reporting headaches once or more per month were asked about migraine symptoms and were classified as having migraine without aura, migraine with aura, or nonmigraine headache. A comprehensive cardiovascular risk assessment was performed at examinations. Infarct-like lesions were present on MRI in 39.3 percent of men and 24.6 percent of women. After adjusting for age, sex, and follow-up time, participants with midlife migraine with aura were at increased risk for total infarct-like lesions. Lesions in the cerebellum, but not in other locations of the brain, were more prevalent in women with migraine with aura compared with women without headache (23 percent vs. 15 percent); there was no difference in prevalence for men (19 percent vs. 21 percent). The relationship between migraine with aura and cerebellar infarcts was only significant in women, but was not statistically different by the age at which headache symptoms were assessed. Migraine without aura and nonmigraine headache were not associated with an increased risk of lesions. The clinical significance of the infarct-like lesions, such as whether the individuals with them had any symptoms, was not assessed.
"In summary, this study suggests that a remote history of migraine with aura is associated with brain lesions commonly found in older populations. Results persisted after controlling for cardiovascular risk factors and history of cardiovascular disease, thus suggesting that the mechanism linking the migraine aura with these lesions is independent of the usual risk factors for ischemic vascular disease and may be specifically related to migraine with aura. Additional longitudinal studies with repeated MRIs are needed to better establish the temporality and dose-response relationship between migraine with aura and brain infarcts. Finally, the clinical implications of the infarct-like lesions identified have not been established and will require investigation," the authors write.
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. Editorial: Migraine and Cerebral Infarct-like Lesions on MRI - An Observation, Not a Disease
Tobias Kurth, MD, Sc.D., of the University Pierre et Marie Curie, Paris, and Christophe Tzourio, M.D., Ph.D., of the University Pierre et Marie Curie and Harvard School of Public Health, Boston, write in an accompanying editorial that the clinical implications of this study "should be interpreted with caution."
"In the absence of the source and the nature of infarct-like lesions and the absence of clinical symptoms or consequences, it is premature to conclude that migraine has hazardous effects on the brain. In this regard, brain scans among patients with migraine should not be initiated to detect silent brain lesions but to rule out rare secondary forms of migraine among those patients with atypical migraine forms or migraine courses. However, the study raises important questions. New studies examining the association of migraine with structural brain changes and brain function should improve understanding of the associations and perhaps further unveil migraine-specific mechanisms."
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. EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), Tuesday, June 23, 2009
Heart Electrical Conduction Abnormality Believed Not to be Serious May Pose Cardiovascular Risks
CHICAGO—New research indicates that a finding on a routine electrocardiogram that signals a disorder of the electrical conducting system in one part of the heart and previously believed to be benign is associated with an increased risk for atrial fibrillation, the implantation of a pacemaker or death, according to a study in the June 24 issue of JAMA. Prolongation of the electrocardiographic PR interval, also known as first-degree atrioventricular block (AVB) when the PR interval exceeds 200 milliseconds, represents delayed conduction of electrical impulses from the atria to the ventricles. It is frequently encountered in clinical practice. For patients who are not hospitalized, first-degree AVB typically occurs in the absence of cardiovascular disease. "The clinical significance of first-degree AVB in this setting is unclear. Several prior studies suggest that first-degree AVB has a benign prognosis, although these studies were based on young, healthy men in the military," the authors write. Susan Cheng, M.D., of the Framingham Heart Study, Framingham, Mass., and colleagues examined the prognosis associated with first-degree AVB. The study included 7,575 individuals (average age, 47 years; 54 percent women) from the community-based Framingham Heart Study who underwent electrocardiography between 1968-1974, with follow-up through 2007. During the follow-up period, 481 participants developed atrial fibrillation (AF), 124 required implantation of a pacemaker, and 1,739 died. The researchers found that individuals with first-degree AVB had an increased risk of future AF (approximately 2-fold), pacemaker implantation (approximately 3-fold) and moderately (1.4-fold) increased risk of all-cause death, compared with individuals without first-degree AVB. After adjustment for conventional risk factors, the PR interval was a significant predictor of all 3 outcomes. Each 20-millisecond increment in the PR interval was associated with an increased risk for AF, pacemaker implantation, and all-cause death.
"The validity of these findings is supported by the large, community-based sample, the routine surveillance of all participants for cardiovascular outcomes, and the long period of follow-up," the authors write. "These results suggest that the natural history of first-degree AVB is not as benign as previously believed. Additional studies are needed to determine appropriate follow-up for individuals found to have prolongation of the PR interval on a routine electrocardiogram."
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.
JAMA REPORTS
VIDEO: Windows Media | Quicktime
OBESITY UNDER 40 MAY INCREASE RISK OF PANCREATIC CANCER IN THE FUTURE
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