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March 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
ARCHIVES OF INTERNAL MEDICINE NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, March 23, 2009)
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. 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), MONDAY, March 23, 2009
Eating Red and Processed Meat Associated With Increased Risk of Death
CHICAGO—Individuals who eat more red meat and processed meat appear to have a modestly increased risk of death from all causes and also from cancer or heart disease over a 10-year period, according to a report in the March 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. In contrast, a higher intake of white meat appeared to be associated with a slightly decreased risk for overall death and cancer death. "Meat intake varies substantially around the world, but the impact of consuming higher levels of meat in relation to chronic disease mortality [death] is ambiguous," the authors write as background information in the article. Rashmi Sinha, Ph.D., and colleagues at the National Cancer Institute, Rockville, Md., assessed the association between meat intake and risk of death among more than 500,000 individuals who were part of the National Institutes of Health-AARP Diet and Health Study. Participants, who were between 50 and 71 years old when the study began in 1995, provided demographic information and completed a food frequency questionnaire to estimate their intake of white, red and processed meats. They were then followed for 10 years through Social Security Administration Death Master File and National Death Index databases. During the follow-up period, 47,976 men and 23,276 women died. The one-fifth of men and women who ate the most red meat (a median or midpoint of 62.5 grams per 1,000 calories per day) had a higher risk for overall death, death from heart disease and death from cancer than the one-fifth of men and women who ate the least red meat (a median of 9.8 grams per 1,000 calories per day), as did the one-fifth of men and women who ate the most vs. the least amount of processed meat (a median of 22.6 grams vs. 1.6 grams per 1,000 calories per day). When comparing the one-fifth of participants who ate the most white meat to the one-fifth who ate the least white meat, those with high white meat intake had a slightly lower risk for total death, death from cancer and death from causes other than heart disease or cancer. "For overall mortality, 11 percent of deaths in men and 16 percent of deaths in women could be prevented if people decreased their red meat consumption to the level of intake in the first quintile [one-fifth]. The impact on cardiovascular disease mortality was an 11 percent decrease in men and a 21 percent decrease in women if the red meat consumption was decreased to the amount consumed by individuals in the first quintile," the authors write. "For women eating processed meat at the first quintile level, the decrease in cardiovascular disease mortality was approximately 20 percent." There are several mechanisms by which meat may be associated with death, the authors note. Cancer-causing compounds are formed during high-temperature cooking of meat. Meat also is a major source of saturated fat, which has been associated with breast and colorectal cancer. In addition, lower meat intake has been linked to a reduction in risk factors for heart disease, including lower blood pressure and cholesterol levels.
"These results complement the recommendations by the American Institute for Cancer Research and the World Cancer Research Fund to reduce red and processed meat intake to decrease cancer incidence," the authors conclude. "Future research should investigate the relation between subtypes of meat and specific causes of mortality."
Editor's Note: This research was supported in part by the Intramural Research Program of the NIH, National Cancer Institute. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. Editorial: Reducing Meat Consumption Has Benefits Beyond Better Health
"The publication by Sinha et al is timely," writes Barry M. Popkin, Ph.D., of the University of North Carolina, Chapel Hill, in an accompanying editorial. "There is a global tsunami brewing, namely, we are seeing the confluence of growing constraints on water, energy and food supplies combined with the rapid shift toward greater consumption of all animal source foods." "Not only are components of the animal-source foods linked to cancer, as shown by Sinha et al, but many other researchers have linked saturated fat and these same foods to higher rates of cardiovascular disease," Dr. Popkin writes. "What do we do?"
Because there are health benefits to eating some red and white (although not processed) meats, the consensus is not for a complete shift to vegan or vegetarian diets, Dr. Popkin concludes. "Rather, the need is for a major reduction in total meat intake, an even larger reduction in processed meat and other highly processed and salted animal source food products and a reduction in total saturated fat."
Editor's Note: The author is not a vegetarian and has no financial conflict of interest related to any food product as it affects 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. EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, March 23, 2009
Increasing Number of Americans Have Insufficient Levels of Vitamin D
CHICAGO—Average blood levels of vitamin D appear to have decreased in the United States between 1994 and 2004, according to a report in the March 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. Clinicians previously believed the major health problems associated with vitamin D deficiency were rickets in children and reduced bone mineral content in adults, conditions reduced by fortifying foods with vitamin D, according to background information in the article. More recently, insufficient vitamin D levels have been associated with cancer, heart disease, infection and suboptimal health overall. Evidence suggests that levels of 30 nanograms per milliliter to 40 nanograms per milliliter may be needed for optimum health "Vitamin D supplementation appears to mitigate the incidence and adverse outcomes of these diseases and may reduce all-cause mortality," the authors write. However, currently recommended levels of supplementation—200 international units per day from birth to age 50, 400 international units per day from age 51 to 70 and 600 international units per day for adults age 71 and older—focus primarily on improving bone health. In addition, decreases in outdoor physical activities and successful campaigns to reduce sun exposure may have contributed to vitamin D insufficiency, since sunlight exposure is a main determinant of vitamin D status in humans. Adit A. Ginde, M.D., M.P.H., of the University of Colorado Denver School of Medicine, Aurora, and colleagues compared levels of serum 25-hydroxyvitamin D (25[OH]D, a measure of the amount of vitamin D in the blood) from the Third National Health and Nutrition Examination Survey (NHANES III), collected between 1988 and 1994, to those collected during NHANES 2001-2004. Complete data were available for 18,883 participants in the first survey and 13,369 participants in the second survey. "Overall, the mean [average] serum 25(OH)D level in the U.S. population was 30 nanograms per milliliter during the 1988-1994 collection and decreased to 24 nanograms per milliliter during the 2001-2004 collection," the authors write. The prevalence of levels lower than 10 nanograms per milliliter increased from 2 percent to 6 percent between the two time periods, and fewer individuals had levels 30 nanograms per milliliter or higher (45 percent vs. 23 percent). Racial and ethnic differences persisted throughout the surveys; among non-Hispanic blacks, the prevalence of 25(OH)D levels of less than 10 nanograms per milliliter increased from 9 percent to 29 percent and levels of more than 30 nanograms per milliliter or higher decreased from 12 percent to 3 percent. "These findings have important implications for health disparities and public health," the authors write. "We found that the mean serum 25(OH)D level in the U.S. population dropped by 6 nanograms per milliliter from the 1988-1994 to the 2001-2004 data collections. This drop was associated with an overall increase in vitamin D insufficiency to nearly three of every four adolescent and adult Americans."
"Current recommendations for dosage of vitamin D supplements are inadequate to address this growing epidemic of vitamin D insufficiency," they conclude. "Increased intake of vitamin D (1,000 international units per day or more)—particularly during the winter months and at higher latitudes—and judicious sun exposure would improve vitamin D status and likely improve the overall health of the U.S. population. Large randomized controlled trials of these higher doses of vitamin D supplementation are needed to evaluate their effect on general health and mortality."
Editor's Note: Senior author Dr. Camargo was supported by the Massachusetts General Hospital Center for D-receptor Activation Research, and he and co-author Dr. Liu were 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. EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, March 23, 2009
Smokers May Have Increased Risk of Pancreatitis
CHICAGO—Smoking appears to be associated with an increased risk of acute and chronic pancreatitis, according to a report in the March 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. In addition, the risk of developing the disease may be higher in those who smoke more. The occurrence of pancreatitis (an inflammation of the pancreas usually characterized by abdominal pain) has increased in recent decades, according to background information in the article. Acute and chronic pancreatitis are believed to be commonly caused by gallstone disease and excessive alcohol use, respectively. Studies have suggested that smoking may be associated with damage to the pancreas, but since smoking may be associated with alcohol use and risk of gallstone disease, it is difficult to note whether smoking is an independent risk factor for the disease. Janne Schurmann Tolstrup, M.Sc., Ph.D., of the National Institute of Public Health, University of Southern Denmark, Copenhagen, and colleagues analyzed results from physical examinations and lifestyle habit self-administered questionnaires of 17,905 participants (9,573 women and 8,332 men) to determine if smoking was associated with an increased risk of acute or chronic pancreatitis independent of alcohol consumption and gallstone disease. Participants were followed up for an average of 20.2 years. "Overall, 58 percent of the women and 68 percent of the men were current smokers, 15 percent of the women and 19 percent of the men were ex-smokers and 28 percent of the women and 13 percent of the men had never smoked," the authors write. "Participants who at baseline reported smoking or being previous smokers had higher risks of developing acute and chronic pancreatitis compared with non-smokers." By the end of the study, 235 participants (113 women and 122 men) had developed acute (160 cases) or chronic (97 cases) pancreatitis, with some participants having developed both. About 46 percent of pancreatitis cases were attributable to smoking in this group. Although alcohol intake was associated with increased risk of pancreatitis, the risk of pancreatitis associated with smoking was independent of alcohol and gallstone disease.
"Apart from the epidemiologic evidence of an association between smoking and development of acute and chronic pancreatitis, a biological effect of smoking seems plausible because both animal studies and human studies have demonstrated changes of the pancreas and in pancreatic functioning after exposure to tobacco smoke," they conclude.
Editor's Note: This study was supported by grants from the Danish National Board of Health and the Danish Medical Research Council. 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), MONDAY, March 23, 2009
Vitamin D Supplements Associated With Reduced Fracture Risk in Older Adults
CHICAGO—Oral vitamin D supplements at a dose of at least 400 international units per day are associated with a reduced risk of bone fractures in older adults, according to results of a meta-analysis published in the March 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. "The anti-fracture benefits of vitamin D have been questioned by several recent trials, leading to uncertainty among patients and physicians regarding recommendations for vitamin D supplementation," the authors write as background information in the article. "Factors that may obscure a benefit of vitamin D are low adherence to treatment, low dose of vitamin D or the use of less potent ergocalciferol (vitamin D2)." Heike A. Bischoff-Ferrari, Dr.P.H., of the University of Zurich, University Hospital, Zurich, Switzerland, and colleagues performed a meta-analysis on 12 previously published clinical trials of oral vitamin D supplements among adults age 65 or older. These double-blind randomized controlled trials involved 42,279 participants (average age 78) and looked at non-vertebral (non-spinal) fractures, including eight trials of 40,886 participants specifically studying hip fractures. When the results of the trials were pooled, vitamin D supplements decreased the risk of non-vertebral fractures by 14 percent and of hip fractures by 9 percent. The authors then pooled the results of only the nine trials in which participants received doses of more than 400 international units per day. At this dosage, vitamin D supplements reduced non-vertebral fractures by 20 percent and hip fractures by 18 percent. Doses of 400 international units per day or lower did not reduce the risk of either fracture type. A greater reduction in risk was also seen among trial participants whose blood levels of 25-hydroxyvitamin D (a commonly used measure of blood vitamin D levels) achieved a greater increase. Among individuals taking high doses of vitamin D, additional calcium did not appear to have any further protective effect against fractures. "Physiologically, the calcium-sparing effect of vitamin D may explain why we did not see an additional benefit of calcium supplementation at a higher dose of vitamin D," the authors write.
"The greater fracture reduction with a higher received dose or higher achieved 25-hydroxyvitamin D levels for both any non-vertebral fractures and hip fractures suggests that higher doses of vitamin D should be explored in future research to optimize anti-fracture efficacy," they conclude. "Also, it is possible that greater benefits may be achieved with earlier initiation of vitamin D supplementation and longer duration of use. Our results do not support use of low-dose vitamin D with or without calcium in the prevention of fractures among older individuals."
Editor's Note: This study was supported by a Swiss National Foundation Professorship grant and a fellowship grant by the Robert Bosch Foundation. 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), MONDAY, March 23, 2009
High Triglyceride Levels Common, Often Untreated Among Americans
CHICAGO—High concentrations of blood fats known as triglycerides are common in the United States, according to a report in the March 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. Lifestyle changes are the preferred initial treatment for hypertriglyceridemia (the resulting condition), but physical inactivity, obesity and other modifiable risk factors remain prevalent. "Increasing evidence supports triglyceride concentration as a risk factor for cardiovascular disease," the authors write as background information in the article. "If triglyceride concentrations are indeed a risk factor for cardiovascular disease, then it becomes important to establish the prevalence of hypertriglyceridemia in the U.S. population and to learn about the degree of pharmacologic management of this risk factor." Earl S. Ford, M.D., M.P.H., and colleagues at the Centers for Disease Control and Prevention, Atlanta, examined data for 5,610 participants age 20 or older who participated in the National Health and Nutrition Examination Surveys between 1999 and 2004. The 2,837 men and 2,773 women were interviewed at home and then invited to attend a mobile examination center, where they answered additional questions, underwent examinations and provided blood samples. A total of 33.1 percent of participants had a triglyceride concentration of 150 milligrams per deciliter or higher (between 150 and 199 milligrams per deciliter is defined as borderline high by the 2001 National Cholesterol Education Program report), 17.9 percent had a concentration of 200 milligrams per deciliter or higher (defined as high), 1.7 percent had a concentration of 500 milligrams per deciliter or higher and 0.4 percent had a concentration of 1,000 milligrams per deciliter or higher. Compared with those who did not have hypertriglyceridemia, those who did were more likely to be older, be white, have not pursued an education beyond high school, smoke, be overweight or obese or have diabetes. "An important approach to the patient with hypertriglyceridemia is the implementation of non-pharmacological interventions," the authors write. "The high percentages of participants with a triglyceride concentration of 200 milligrams per deciliter or higher who were overweight or obese, who failed to engage in physical activity for approximately 150 minutes per week or who smoked attest to the challenge confronting health care providers in working with their patients to implement therapeutic lifestyle changes." A total of 1.3 percent of participants used one of three prescription medications (fenofibrate, gemfibrozil or niacin) that treat hypertriglyceridemia, including 2.6 percent of those with a concentration of 150 milligrams per deciliter or higher and 3.6 percent of those with a concentration of 200 milligrams per deciliter or higher. This may reflect uncertainty about the need to treat this abnormality, the authors note. The benefits of pharmacotherapy are clear for patients with levels of 500 milligrams per deciliter or higher, who are at risk for pancreatitis, but therapeutic lifestyle changes remain the initial therapy of choice for those with levels between 200 and 500 milligrams per deciliter.
"As research clarifies uncertainties in the relation between triglyceride concentration and cardiovascular disease, guidelines to treat hypertriglyceridemia will likely be modified," they conclude.
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), MONDAY, March 23, 2009
Family History Associated With Increased Risk of Blood Clots
CHICAGO—Children and siblings of those with venous thrombosis, or blood clots in the veins, appear to have more than double the risk of developing the condition than those without a family history, according to a report in the March 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. Venous thrombosis typically begins in leg veins, although the clot may subsequently break off and travel to the lungs. Several genetic risk factors have been identified that increase risk, according to background information in the article. Carriers of these factors have an additional elevated risk when exposed to an environmental risk factor such as surgical treatment, injury, a period of immobilization or the use of oral contraceptives. "Because universal screening is not cost-effective, research efforts are focused on selection criteria that may be used to increase the chance of finding a genetic risk factor," the authors write. "Family history is an evident candidate." Irene D. Bezemer, M.Sc., and colleagues at Leiden University Medical Center, Leiden, the Netherlands, collected blood samples and information about family history and environmental risk factors from 1,605 patients who had experienced their first clot between 1999 and 2004. Their data was compared with that of 2,159 control participants who were the same sex and age but had not had venous thrombosis. Among patients with venous thrombosis, 505 (31.5 percent) had at least one first-degree relative with a history of the condition, compared with 373 controls (17.3 percent). A positive family history was associated with a more than two-fold increase in the risk of venous thrombosis; the risk was increased further if the relative developed clots at a younger age and as much as quadrupled if more than one relative was affected. Family history did not correspond well with known genetic risk factors, suggesting that there may be unknown genetic risk factors or that venous thrombosis may cluster in a family due to characteristics of the shared household, the authors note. "Both in those with and without genetic or environmental risk factors, family history remained associated with venous thrombosis," the authors write. "The risk increased with the number of factors identified; for those with a genetic and environmental risk factor and a positive family history, the risk was about 64-fold higher than for those with no known risk factor and a negative family history."
The relative risk associated with family history was similar to that associated with a genetic risk factor. “In clinical practice, family history may be more useful for risk assessment than thrombophilia testing,” or laboratory tests that identify genetic or physiological risk factors, the authors conclude.
Editor's Note: This study was supported by a grant from the Netherlands Heart Foundation, a grant from the Dutch Cancer Foundation and a grant from the Netherlands Organisation for Scientific Research. 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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