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ARCHIVES OF INTERNAL MEDICINE NEWS RELEASES

(Embargoed Until: 3 P.M. (CT), Monday, July 28, 2008)

   CURRENT EXERCISE RECOMMENDATIONS MAY NOT BE SUFFICIENT FOR OVERWEIGHT WOMEN TO SUSTAIN WEIGHT LOSS

   DIETARY FACTORS APPEAR TO BE ASSOCIATED WITH DIABETES RISK

   STUDY EXAMINES PREVALENCE OF HEARING LOSS IN THE U.S.

   THYROTROPIN LEVELS ASSOCIATED WITH ALZHEIMER’S DISEASE RISK IN WOMEN

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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, July 28, 2008
Media Advisory: To contact John M. Jakicic, Ph.D., call Sharon Stewart Blake at 412-624-4364.

CURRENT EXERCISE RECOMMENDATIONS MAY NOT BE SUFFICIENT FOR OVERWEIGHT WOMEN TO SUSTAIN WEIGHT LOSS

CHICAGO—In addition to limiting calories, overweight and obese women may need to exercise 55 minutes a day for five days per week to sustain a weight loss of 10 percent over two years, according to a report in the July 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

More than 65 percent of U.S. adults are overweight, a public health concern, according to background information in the article. “Among obese adults, long-term weight loss and prevention of weight regain have been less than desired,” the authors write. “Therefore, there is a need for more effective interventions.” Current recommendations prescribe 30 minutes of moderate physical activity on most days of the week, for a total of 150 minutes per week. However, a growing consensus suggests that more exercise may be needed to enhance long-term weight loss.

To calculate the amount of exercise needed, John M. Jakicic, Ph.D., of the University of Pittsburgh, and colleagues enrolled 201 overweight and obese women in a weight loss intervention between 1999 and 2003. All the women were told to eat between 1,200 and 1,500 calories per day. They were then assigned to one of four groups based on physical activity amount (burning 1,000 calories vs. 2,000 calories per week) and intensity (moderate vs. vigorous). Group meetings focusing on strategies for modifying eating and exercise habits, as well telephone calls with the intervention team, also were conducted over the two-year period.

After six months, women in all four groups had lost an average of 8 percent to 10 percent of their initial body weight. However, most were not able to sustain this weight loss. After two years the women’s weight was an average of 5 percent lower than their initial weight, with no difference between groups.

The 24.6 percent of individuals who did maintain a loss of 10 percent or more over two years reported performing more physical activity (an average of 1,835 calories per week, or 275 minutes per week over the baseline level of activity) than those who lost less weight. They also completed more telephone calls with the intervention team, engaged in more eating behaviors recommended for weight control and had a lower intake of dietary fat.

“This clarifies the amount of physical activity that should be targeted for achieving and sustaining this magnitude of weight loss, but also demonstrates the difficulty of sustaining this level of physical activity,” the authors write. “Research is needed to improve long-term compliance with this targeted level of physical activity. Moreover, continued contact with the intervention staff and the ability to sustain recommended eating behaviors also may be important contributing factors to maintaining a significant weight loss that exceeds 10 percent of initial body weight, which suggests that physical activity does not function independently of these other behaviors.”
(Arch Intern Med. 2008;168[14]:1550-1559. Available to the media pre-embargo at www.jamamedia.org)

Editor's Note: Dr. Jakicic is on the Scientific Advisory Board for BodyMedia Inc. and the Calorie Control Council (www.caloriescount.com). This study was supported by a grant from the National Institutes of Health and the National Heart, Lung, and Blood 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, July 28, 2008
Media Advisory: To contact Julie R. Palmer, Sc.D., call Gina DiGravio at 617-638-8491. To contact corresponding author Nita G. Forouhi, F.F.P.H., Ph.D., e-mail nita.forouhi{at}mrc-epid.cam.ac.uk. To contact Lesley F. Tinker, Ph.D., call Kristen Woodward at 206-667-5095. To contact corresponding editorialist Mark N. Feinglos, M.D., C.M., call Debbe Geiger at 919-684-4148.

DIETARY FACTORS APPEAR TO BE ASSOCIATED WITH DIABETES RISK

CHICAGO—Drinking more sugar-sweetened beverages or eating fewer fruits and vegetables both may be associated with an increased risk of type 2 diabetes, whereas eating a low-fat diet does not appear to be associated with any change in diabetes risk, according to three reports in the July 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Diabetes rates continue to increase, particularly in developed countries, according to background information in the articles. By the year 2030, 11.2 percent of U.S. adults are expected to have the condition. Obesity is the strongest modifiable risk factor for the development of type 2 diabetes.

In one study, Julie R. Palmer, Sc.D., of the Slone Epidemiology Center, Boston University, and colleagues examined the association between type 2 diabetes, weight gain and the consumption of sugar-sweetened soft drinks and fruit drinks in 43,960 African American women. In 1995 and again in 2001, the women completed a questionnaire about the types of foods and beverages they typically consumed. A total of 17 percent reported drinking one sugar-sweetened soft drink each day, 32 percent drank one sweetened fruit drink each day and 22 percent had at least one glass of orange juice or grapefruit juice.

Over 10 years of follow-up, 2,713 of the women developed type 2 diabetes. Those who drank more regular soft drinks and fruit drinks—including regular soda, other fruit juices, fortified fruit drinks and Kool-Aid but not diet soda, orange juice or grapefruit juice—were more likely to develop diabetes than those who drank less of those beverages.

Women who drank two or more soft drinks per day had a 24 percent increase in diabetes risk compared with women who drank less than one soft drink per month, and those who drank two or more fruit drinks per day had a 31 percent increased risk compared with women who drank less than one per month. Diet soft drinks, grapefruit juice and orange juice were not associated with diabetes risk.

When the researchers adjusted for body mass index (BMI), the association between soft drinks and diabetes risk decreased. However, the association between fruit drinks and diabetes risk did not appear dependent on BMI. “Our study suggests that the mechanism for the increase in diabetes risk associated with soft drink consumption is primarily through increased weight. Reducing consumption of soft drinks or switching from sugar-sweetened soft drinks to diet soft drinks is a concrete step that women may find easier to achieve than other approaches to weight loss,” the authors write.

“Finally, it should be noted that consumption of fruit drinks conveyed as high an increase in risk as did consumption of soft drinks. Fruit drinks typically contain as many or more calories compared with soft drinks and, like soft drinks, may not decrease satiety to the same extent as solid food,” they conclude. “The public should be made aware that these drinks are not a healthy alternative to soft drinks with regard to risk of type 2 diabetes.”

In another study, Anne-Helen Harding, Ph.D., of Addenbrooke’s Hospital, Cambridge, England, and colleagues analyzed blood vitamin C levels and fruit and vegetable intake in 21,831 individuals (average age 58) who did not have diabetes at the beginning of the study (1993 to 1997). Vitamin C level is a good indicator of fruit and vegetable consumption, the authors note, because these foods are the main source of vitamin C in the Western diet. Participants provided blood samples and reported how often they ate fruits and vegetables on a food frequency questionnaire.

Over 12 years of follow-up, 735 participants developed diabetes. Those with higher blood levels of vitamin C were substantially less likely to develop diabetes. “Compared with men and women in the bottom quintile [one-fifth] of plasma vitamin C, the odds of developing diabetes was 62 percent lower for those in the top quintile of plasma vitamin C,” the authors write. “A weaker inverse association between fruit and vegetable consumption and diabetes risk was observed.”

Fruits and vegetables may reduce diabetes risk by preventing obesity or by providing nutrients that protect against diabetes, including antioxidants, the authors note. “Because fruits and vegetables are the main sources of vitamin C, the findings suggest that eating even a small quantity of fruits and vegetables may be beneficial and that the protection against diabetes increases progressively with the quantity of fruit and vegetables consumed,” they conclude.

In a third article, Lesley F. Tinker, Ph.D., of the Women’s Health Initiative, Fred Hutchison Cancer Research Center, Seattle, and colleagues studied the effects of eating a low-fat diet on diabetes risk in 48,835 post-menopausal women. From 1993 to 2005, 29,294 of the women were randomly assigned to continue eating their usual diet while 19,541 were given a low-fat (20 percent of calories from fat) diet with increased levels of fruits, vegetables and whole grains. The diet was not intended to help participants lose weight.

A total of 1,303 of the women eating the low-fat diet (7.1 percent) and 2,039 women eating their usual diet (7.4 percent) developed diabetes over the 8.1 years of the study. There was no significant reduction in the risk of developing diabetes among women on the low-fat diet. However, “trends toward reduced incidence were greater with greater decreases in total fat intake and weight loss,” the authors write.

Women in the low-fat diet group lost about 1.9 kilograms or 4.2 pounds more weight over the course of the study than women in the regular diet group. “Weight loss, rather than macronutrient composition, may be the dominant predictor of reduced risk of diabetes,” the authors conclude.
(Arch Intern Med. 2008;168[14]: 1487-1492, 1493-1499, 1500-1511. Available to the media pre-embargo at www.jamamedia.org).

EDITORIAL: CALORIES MAY COUNT THE MOST IN REDUCING DIABETES RISK

“The relationship between food and the development of type 2 diabetes mellitus has been debated for many years,” write Mark N. Feinglos, M.D., C.M., and Susan E. Totten, R.D., of Duke University Medical Center, Durham, N.C., in an accompanying editorial.

“So, what do we now know about the impact of diet on the development of type 2 diabetes mellitus, and what remains unknown?” they write. “We know that, as a population, we eat too much for our level of activity, and we are growing fatter as a result. In association with this increasing weight, we are in the midst of a dramatic increase in the number of cases of type 2 diabetes mellitus, not only in the United States, but in countries like India and China, where the caloric intake has also increased.”

“We do not know whether specific macronutrients put genetically predisposed people at increased risk of developing diabetes mellitus, or whether adding lots of fat or refined carbohydrate to the diet just makes it easier to take in excess calories,” Drs. Feinglos and Totten conclude. “Studies to isolate these effects will be difficult to perform, but, until we have more information, we have to assume that calories trump everything else, and that our number one goal for the reduction of new cases of type 2 diabetes mellitus should be to reduce the intake of high-energy, low-benefit foods, particularly in young members of the most vulnerable populations.”
(Arch Intern Med. 2008;168[14]:1485-1486. Available to the media pre-embargo at www.jamamedia.org)

Editor's Note: Please see the articles 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, July 28, 2008
Media Advisory: To contact Yuri Agrawal, M.D., call David March at 410-955-1534.

STUDY EXAMINES PREVALENCE OF HEARING LOSS IN THE U.S.

CHICAGO—Hearing loss may be more prevalent in American adults than previously reported, according to a study in the July 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Hearing loss can be a disabling condition affecting verbal language processing and limiting communication and social connectivity, according to background information in the article. “Such communication difficulties negatively affect work productivity, health-related quality of life and cognitive and emotional status. These disabilities impede health care access and use, with possible adverse consequences to health and survival.”

Hearing impairment is known to be highly common and is considered to be a societal problem. Although national estimates of hearing loss are lacking, the incidence of this condition in the U.S. is predicted to have risen significantly because of the aging population and growing use of personal listening devices.

Yuri Agrawal, M.D., of Johns Hopkins Hospital, Baltimore, and colleagues evaluated data from a large national survey, including hearing tests, administered to 5,742 Americans age 20 to 69 from 1999 to 2004. Researchers assessed hearing loss of 25 decibels or higher at speech frequencies (0.5, 1, 2 and 4 kilohertz) and at high frequencies (3, 4 and 6 kilohertz). Demographic characteristics and known risk factors for hearing loss (smoking, noise exposure and cardiovascular risks) were also noted.

From 2003 to 2004, 16.1 percent (an estimated 29 million) of American adults had speech frequency hearing loss in one (8.9 percent) or both ears (7.3 percent). “Thirty-one percent of participants (equivalent to an estimated 55 million Americans) had high-frequency hearing loss [12 percent in one ear and 19 percent in both],” the authors write. Hearing loss, especially at high frequency, was found in participants age 20 to 29 (8.5 percent prevalence) and in those age 30 to 39 (17 percent prevalence).

Men were 5.5 times more likely than women to have hearing loss. Black participants were 70 percent less likely to have loss of hearing than white participants with white and Mexican American men having the highest occurrence of high-frequency hearing loss and hearing loss in both ears. “Increases in hearing loss prevalence occurred earlier among participants with smoking, noise exposure and cardiovascular risks,” the authors write.

“The results of our study suggest that prevention (through risk factor reduction) and screening must begin at least in young adulthood and that efforts should be intensified among white and Mexican American men,” the authors conclude. “Hearing loss reduces health-related quality of life and access to health care.” Reducing the incidence of hearing loss through prevention and management programs may produce public health benefits, they note.
(Arch Intern Med. 2008;168[14]:1522-1530. 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, July 28, 2008
Media Advisory: To contact Zaldy S. Tan, M.D., M.P.H., call Jennifer Davis at 781-247-8168.

THYROTROPIN LEVELS ASSOCIATED WITH ALZHEIMER’S DISEASE RISK IN WOMEN

CHICAGO—Women with low or high levels of the hormone thyrotropin, which affects thyroid gland function and thyroid hormone levels, appear to have a higher risk of developing Alzheimer’s disease, according to a report in the July 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

A clinically detectable over- or under-active thyroid has long been recognized as a potentially reversible cause of cognitive (thinking, learning and memory) impairment, according to background information in the article. Previous studies have examined whether levels of thyrotropin, a hormone that is secreted by the pituitary gland and helps regulate thyroid gland function, is associated with cognitive performance in individuals with normal thyroid function. However, results have been inconsistent.

Zaldy S. Tan, M.D., M.P.H., of Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, and colleagues measured thyrotropin levels in 1,864 individuals (average age 71) without cognitive problems between 1977 and 1979. Participants—part of the community-based Framingham Study—were assessed for dementia at that time and again every two years.

Over an average of 12.7 years of follow-up, 209 participants developed Alzheimer’s disease. After adjusting for other related factors, the researchers found that women with the lowest (less than 1 milli-international unit per liter) and highest (more than 2.1 milli-international units per liter) levels of thyrotropin had more than double the risk of developing Alzheimer’s disease. However, no relationship was observed between thyrotropin levels and Alzheimer’s disease risk in men.

“Whether altered thyrotropin levels occur before or after the onset of Alzheimer’s disease, the neuropathologic mechanism is unclear,” the authors write. Changes in the brain caused by Alzheimer’s disease may cause a reduction in the amount of thyrotropin released or changes in the body’s responsiveness to the hormone. Alternatively, low or high thyrotropin levels could damage neurons or blood vessels, leading to cognitive difficulties.

“In conclusion, low and high thyrotropin levels were associated with an increased risk of incident Alzheimer’s disease in women but not in men,” the authors conclude. “These findings should be considered hypothesis–generating and should be validated in other populations before clinical conclusions are drawn.”
(Arch Intern Med. 2008;168[14]:1514-1520. 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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