“This is the first time cortisol reactivity has been identified as a mediator between depressed mood and obesity in girls,” said Elizabeth J. Susman, the Jean Phillips Shibley professor of biobehavioral health at Penn State. “We really haven’t seen this connection in kids before, but it tells us that there are biological risk factors that are similar for obesity and depression.”

Cortisol, a hormone, regulates various metabolic functions in the body and is released as a reaction to stress. Researchers have long known that depression and cortisol are related to obesity, but they had not figured out the exact biological mechanism.

Although it is not clear why high cortisol reactions translate into obesity only for girls, scientists believe it may be due to physiological and behavioral differences — estrogen release and stress eating in girls — in the way the two genders cope with anxiety.

“The implications are to start treating depression early because we know that depression, cortisol and obesity are related in adults,” said Susman.

If depression were to be treated earlier, she noted, it could help reduce the level of cortisol, and thereby help reduce obesity.

“We know stress is a critical factor in many mental and physical health problems,” said Susman. “We are putting together the biology of stress, emotions and a clinical disorder to better understand a major public health problem.”

Susman and her colleagues Lorah D. Dorn, professor of pediatrics, Cincinnati Children’s Hospital Medical Center, and Samantha Dockray, postdoctoral fellow, University College London, used a child behavior checklist to assess 111 boys and girls ages 8 to 13 for symptoms of depression. Next they measured the children’s obesity and the level of cortisol in their saliva before and after various stress tests.

“We had the children tell a story, make up a story, and do a mental arithmetic test,” said Susman. “The children were also told that judges would evaluate the test results with those of other children.”

Statistical analyses of the data suggest that depression is associated with spikes in cortisol levels for boys and girls after the stress tests, but higher cortisol reactions to stress are associated with obesity only in girls. The team reported its findings in a recent issue of the Journal of Adolescent Health.

“In these children, it was mainly the peak in cortisol that was related to obesity,” Susman explained. “It was how they reacted to an immediate stress.”

The National Institutes of Health supported this work.

Source:
Amitabh Avasthi
Penn State

Successful weight loss in obese individuals is defined as a reduction of 10 percent or more of initial body weight maintained for at least a year. The jury is still out, however, as to whether fast or slow initial weight loss is the best approach for long-term weight control in obese patients. On the one hand, there is evidence that losing weight slowly initially results in continued weight loss, reduced risk of weight regain, and successful long-term weight loss maintenance. On the other hand, it has also been shown that the greater the initial weight loss in obese patients, the larger the total weight loss observed longer term.

Nackers and team’s study examines the association between rate of initial weight loss and long-term maintenance of lost weight, by looking specifically at whether losing weight at a slow initial rate results in larger long-term weight reduction and less weight regain than losing weight at a fast initial rate.

The authors analyzed data for 262 middle-aged obese women who took part in the Treatment of Obesity in Underserved Rural Settings (TOURS) trial. These women followed a six-month lifestyle program encouraging them to reduce their calorie intake and increase their moderate intensity physical activity to achieve an average weight loss of 0.45kg per week. They were then supported for a further year with an extended care program involving contact twice a month in the form of group sessions, telephone contact or newsletters.

Nackers and team split the women into three groups according to how much weight they lost in the first month of the intervention. Women in the FAST group lost over 0.68kg per week; those in the MODERATE group lost between 0.23 and 0.68kg per week; women in the SLOW group lost less than 0.23kg per week in that first month. The authors then looked at the womens’ weight loss at 6 and 18 months, as well as any weight regain.

They found that there were long-term advantages to fast initial weight loss. Fast weight losers lost more weight overall, maintained their weight loss for longer and were not more likely to put weight back on than the more gradual weight losers. In particular, women in the FAST group were five times more likely to achieve the clinically significant 10 percent weight loss at 18 months than those in the SLOW group and those in the MODERATE group were nearly three times more likely to achieve this milestone than women in the SLOW group.

The authors conclude: “Our study provides further evidence that, within the context of lifestyle treatment, losing weight at a fast initial rate leads to greater short-term weight reductions, does not result in increased susceptibility to weight regain, and is associated with larger weight losses and overall long-term success in weight management. We suggest that, within lifestyle weight control programs, substantial efforts should be focused on promoting large rather than small behavioral changes during the initial weeks of treatment.”

Reference:
1. Nackers LM et al (2010). The association between rate of initial weight loss and long-term success in obesity treatment: does slow and steady win the race? International Journal of Behavioral Medicine, DOI 10.1007/s12529-010-9092-y

More importantly, according to two new studies led by a University of Utah human geneticist, fruit flies use the same molecular mechanisms as humans to help maintain proper balances of cholesterol and a key form of stored fat that contributes to obesity. The findings mean that as researchers try to learn more about the genetic and biological processes through which people regulate cholesterol and fat metabolism, the humble fruit fly, also called Drosophila, can teach humans much about themselves.

“Not a lot is known about these regulatory mechanisms in people,” says Carl S. Thummel, Ph.D., professor of human genetics at the U of U School of Medicine and senior author on the two studies. “But we can learn a lot by studying metabolic control in fruit flies and apply what we learn to humans.”

High cholesterol and obesity, which affects an estimated 25 percent to 30 percent of the U.S. population, are linked to heart disease, diabetes, and other diseases that take huge tolls on health and add billions of dollars to the nation’s medical bills. Understanding the processes that regulate cholesterol and fat in humans could be critical for addressing those health risks in people, Thummel believes.

The two studies identify a nuclear receptor, DHR96, which plays a critical role in regulating the balance or homeostasis of cholesterol and another fat molecule called triacylglycerol (TAG). Nuclear receptors are proteins that sense the presence of chemical compounds within cells. DHR96 corresponds closely to a nuclear receptor in humans, called LXR, that is known to regulate cholesterol levels.

In a study published Dec. 2 in Genes & Development, Thummel and colleagues at the U of U and two Canadian universities show that DHR96 helps regulate cholesterol in fruit flies by binding with this compound. When this binding occurs, it allows DNA to be read, which switches genes on and off that help maintain proper levels of cholesterol, according to Thummel, who also holds an H.A. and Edna Benning Presidential Endowed Chair in Human Genetics.

The researchers used a technique developed by University of Utah biologist Kent Golic, Ph.D., in which they silenced or disabled the DHR96 protein so it couldn’t function in fruit flies. They then grew flies in which DHR96 was silenced. Depending on what the fruit flies were fed, lean or fat diets, they had either too little or too much cholesterol. Flies fed too little cholesterol died, while those with too much developed hypercholesterolemia or chronically excessive cholesterol levels. At the same time, flies in which DHR96 functioned normally maintained a proper level of cholesterol.

“When they lacked the DHR96 receptor, the flies were unable to maintain cholesterol homeostasis,” Thummel says. “This is similar to what happens in humans who have high cholesterol levels.”

Fruit flies are good for such research insights in large part because of the insects’ short life span – about 30 days – meaning their development and biological processes are more easily observed than in other, longer-lived models, such as mice. Fruit flies also are easy to manipulate genetically and are less expensive to study compared to mice or other models, according to Thummel. In addition, the mechanisms by which metabolism is controlled in fruit flies are very similar to those in mice or humans.

“We can do a lot more mechanistic studies in a fly than are possible in a mouse,” he says. “We can study metabolic pathways faster and more in-depth.”

Along with its important role in helping to maintain proper levels of cholesterol, DHR96 also plays an integral part in regulating dietary fat metabolism, Thummel and another U of U researcher report in a Dec. 2 study in Cell Metabolism.

In flies in which DHR96 was silenced, TAG levels were markedly reduced in the intestine, making the insects resistant to diet-induced obesity. But when DHR96 was overexpressed, meaning there were higher levels of the protein, it led to increased TAG levels and made the flies more prone to being overweight. These findings show that DHR96 is required for breaking down dietary fat in the intestine of fruit flies and provide insight into how dietary fat metabolism is regulated in Drosophila.

“This nuclear receptor plays a major role in sensing and regulating cholesterol and TAG uptake in the intestine in fruit flies,” Thummel says. “It functions similarly to the way LXR functions in humans, although we have a relatively poor understanding about how LXR controls these pathways.”

In his future studies, Thummel intends to learn more about how DHR96 regulates metabolism by studying the functions of the genes that it controls.

Source: Phil Sahm
University of Utah Health Sciences

The risks were lower for total stroke, clot-related (ischemic) stroke and bleeding (hemorrhagic) stroke, researchers said.

Compared to women who didn’t walk:

• Women who usually walked at a brisk pace had a 37 percent lower risk of any type of stroke and those who walked two or more hours a week had a 30 percent lower risk of any type of stroke.
• Women who typically walked at a brisk pace had a 68 percent lower risk of hemorrhagic stroke and those who walked two or more hours a week had a 57 percent lower risk of hemorrhagic stroke.
• Women who usually walked at a brisk pace had a 25 percent lower risk of ischemic stroke and those who usually walked more than two hours a week had a 21 percent lower risk of ischemic stroke – both “borderline significant,” according to researchers.

“Physical activity, including regular walking, is an important modifiable behavior for stroke prevention,” said Jacob R. Sattelmair, M.Sc., lead author and doctoral candidate in epidemiology at Harvard School of Public Health in Boston, Mass. “Physical activity is essential to promoting cardiovascular health and reducing risk of cardiovascular disease, and walking is one way of achieving physical activity.”

More physically active people generally have a lower risk of stroke than the least active, with more-active persons having a 25 percent to 30 percent lower risk for all strokes, according to previous studies.

“Though the exact relationship among different types of physical activity and different stroke subtypes remains unclear, the results of this specific study indicate that walking, in particular, is associated with lower risk of stroke,” Sattelmair said.

Researchers followed 39,315 U.S. female health professionals (average age 54, predominantly white) participating in the Women’s Health Study. Every two to three years, participants reported their leisure-time physical activity during the past year – specifically time spent walking or hiking, jogging, running, biking, doing aerobic exercise/aerobic dance, using exercise machines, playing tennis/squash/racquetball, swimming, doing yoga and stretching/toning. No household, occupational activity or sedentary behaviors were assessed.

They also reported their usual walking pace as no walking, casual (about 2 mph), normal (2.9 mph), brisk (3.9 mph) or very brisk (4 mph).

Sattelmair noted that walking pace can be assessed objectively or in terms of the level of exertion, using a heart rate monitor, self-perceived exertion, “or a crude estimate such as the ‘talk test’ – wherein, for a brisk pace, you should be able to talk but not able to sing. If you cannot talk, slow down a bit. If you can sing, walk a bit faster.”

During 11.9 years of follow-up, 579 women had a stroke (473 were ischemic, 102 were hemorrhagic and four were of unknown type).

The women who were most active in their leisure time activities were 17 percent less likely to have any type of stroke compared to the least-active women.

Researchers didn’t find a link between vigorous activity and reduced stroke risk. The reason is unclear, but they suspect that too few women reported vigorous activity in the study to get an accurate picture and/or that moderate-intensity activity may be more effective at lowering blood pressure as suggested by some previous research.

Stroke is the third leading cause of death and a leading cause of serious disability in the United States, so it’s important to identify modifiable risk factors for primary prevention, Sattelmair said.

An inverse association between physical activity and stroke risk is consistent across genders. But there tend to be differences between men and women regarding stroke risk and physical activity patterns.

“The exact relation between walking and stroke risk identified in this study is not directly generalizable to men,” Sattelmair said. “In previous studies, the relation between walking and stroke risk among men has been inconsistent.”

The study is limited because it was observational and physical activity was self-reported. But strengths are that it was large and long-term with detailed information on physical activity, he said.

Further study is needed on more hemorrhagic strokes and with more ethnically diverse women, Sattelmair said.

The American Heart Association recommends for substantial health benefits, adults should do at least 150 minutes a week of moderate-intensity or 75 minutes a week of vigorous-intensity aerobic physical activity or a combination.

Co-authors are: Tobias Kurth, M.D., Sc.D.; Julie E. Buring, Sc.D.; and I-Min Lee, M.B.B.S., Sc.D. Individual author disclosures are on the manuscript.

The National Institutes of Health supported the study.

Source:
Birdgette McNeill
American Heart Association

“Insurance companies disputed these figures. Andrea Austin, the assistant director of corporate relations for Northwestern Mutual, in Milwaukee, says the company’s investment in fast-food companies is only about $250 million … about one-fifth of 1 percent of the company’s portfolio, she adds. Austin also disagrees that the company’s fast-food investments represent a disconnect with its mission. ‘We have to determine what’s going to give our policy owners value,’ she says” (Klein, 4/15).

The Wall Street Journal Health Blog: “Study author J. Wesley Boyd, an attending psychiatrist at [Cambridge Health Alliance] and assistant professor at Harvard, defends the numbers, saying according to the database they were correct. He says the U.S. companies studied were primarily life insurers and don’t sell health insurance per se, but that some of the Canadian and U.K. companies covered in the study do sell health insurance” (Hobson, 4/15).

CBS on The American Journal of Public Health study: “The authors write that the recent passage of health care reform will likely expand the reach of the insurance industry, arguing that if insurers are to play a greater role in health care that they should be held to a higher standard of corporate responsibility” (Hartge, 4/15).

AARP Bulletin Today: “Mark Pauly, a professor of health care management at the Wharton School at the University of Pennsylvania, thinks trying to pressure insurers to divest their fast-food holdings is a bit naive. ‘It may be a nice gesture for insurers to say they’re not investing in evil things anymore,’ he says, ‘but it’s hard to imagine that it would have a substantial impact.’ A better idea, he says, ‘would be for the insurance companies to invest a lot more in fast food, then go to the company’s annual meeting and get them to change their policies’” (Sagon, 4/15).

This information was reprinted from kaiserhealthnews.org with kind permission from the Henry J. Kaiser Family Foundation. You can view the entire Kaiser Daily Health Policy Report, search the archives and sign up for email delivery at kaiserhealthnews.org.

Dr. Jay Udani, M.D. from Medicus Research, California, worked with a team of researchers to carry out a randomized, double-blind placebo controlled trial. He said, “For people drinking over half a liter of mangosteen juice a day, the degree of reduction in CRP levels was statistically significant – a reduction of 1.33mg/L compared to an increase of 0.9mg/L in the placebo group”.

Inflammation, as measured here by CRP, is a predictor of cardiovascular disease and a precursor of metabolic syndrome. Reducing inflammation in obese people is a treatment goal, and a natural treatment may be preferable to other treatments which may carry the risk of side effect. According to Udani, “Further studies with a larger population are required to confirm and further define the benefits of this juice, which was safe at all dosages tested”.

Notes:
Evaluation of Mangosteen juice blend on biomarkers of inflammation in obese subjects: a pilot, dose finding study.
Jay K Udani, Betsy B Singh, Marilyn L Barrett and Vijay J Singh
Nutrition Journal (in press)
http://www.nutritionj.com/

Source:
Charlotte Webber
BioMed Central

The analysis of this large Atherosclerosis Risk in Communities (ARIC) Study, which appears in the August issue of Journal of Lipid Research, was carried out by Keri Monda and colleagues at North Carolina and Baylor. They found that over a 12 year period, all individuals who increased their exercise by about 180 metabolic units per week (equivalent to an additional hour of mild or 30 minutes of moderate activity per week) displayed decreased levels of triglycerides and increased levels of the “good” HDL cholesterol. However, statistically significant decreases in the “bad” LDL cholesterol were only observed in women, with particularly strong effects in menopausal women and African-American women. And total cholesterol levels were only significantly decreased in African-American women.

The authors speculate that these novel differences may arise from hormonal differences between the sexes, especially considering the extra effects seen post-menopause. The racial differences observed may stem from genetic variations that require further exploration.

The authors do also note that their exercise data was assessed by questionnaire and this was non-scientific, though the particular methodology used has been extremely reliable in other studies. They also note that all evaluated participants were healthy, so these results cannot be generalized to individuals with diabetes or those on cholesterol-lowering medications.

From the article: Longitudinal impact of physical activity on lipid profiles in middle-aged adults: the Atherosclerosis Risk in Communities Study, by Keri L. Monda, Christie M. Ballantyne and Kari North

Source:
Nick Zagorski
American Society for Biochemistry and Molecular Biology

Dr. Ludman’s study included 190 female Group Health patients age 40 to 65 with a body mass index (BMI) of 30 or more: 65 with major depressive disorder and 125 without it. The women had not been seeking treatment, but they enrolled in a one-year behavioral weight loss intervention involving 26 group sessions. The intervention, developed at the University of Minnesota over the past 20 years, has proven at least as good as any other currently available non-medical treatment.

Some previous research had hinted that depression might worsen outcomes in behavioral weight loss programs. That’s why trials of weight loss interventions typically exclude people with major depression.

“We expected women with major depression to lose less weight, attend fewer sessions, eat more calories, and get less exercise than those without depression,” Dr. Ludman said. “We were surprised to find no significant differences between the women who had depression and those who did not have it.” Women had lost around the same amount of weight at 6 months (8 or 9 pounds) and 12 months (7 or 8 pounds), with no significant differences between the groups with and without depression.

“Instead, what made a difference was just showing up,” she said. Women who attended at least 12 sessions lost more weight (14 pounds at 6 months, and 11 pounds at 12 months) than did those who attended fewer sessions (4 pounds at both 6 and 12 months), regardless of whether they had depression. Being depressed didn’t lead them to attend fewer sessions or lose less weight.

“Because of our findings and the well-documented health risks of obesity, we think rigorous efforts should be taken to engage and retain all women in need of such services in intensive weight loss programs,” Dr. Ludman said.

For years, Dr. Ludman and her colleagues have been researching the link between depression and obesity. She is also the coauthor of a self-help workbook called Overcoming Bipolar Disorder: A Comprehensive Workbook for Managing Your Symptoms and Achieving Your Life Goals. Her Harvard coauthors include Mark Bauer, MD. Published in 2008, the book outlines the research-based Life Goals Program to help people live with bipolar disorder.

Dr. Ludman’s co-authors on this study are Group Health psychiatrist Gregory E. Simon, MD, MPH, who is also a senior investigator at Group Health Research Institute; Biostatistician Laura Ichikawa, MS, Project Manager Belinda H. Operskalski, MPH, and Assistant Investigator David Arterburn, MD, MPH of Group Health Research Institute; Jennifer A. Linde, PhD, and Robert W. Jeffery, PhD, of the University of Minnesota School of Public Health in Minneapolis; Paul Rohde, PhD, of the Oregon Research Institute in Eugene; and Emily A. Finch, MA, of Indiana University School of Medicine in Indianapolis.

The National Institute of Mental Health and the Office of Behavioral Social Sciences Research funded this study.

Source:
Joan DeClaire
Group Health Cooperative Center for Health Studies

Half of women fit into two other categories, the study says, and were found to be the least likely to be leaning toward fat. Both types of women in those groups are concerned about nutrition and like to eat healthy.

“The basic attitude that people have about food is related to the likelihood that they’re at risk for obesity and weight gain,” said researcher Dennis Degeneffe, a study co-author.

The study, which appears in the December issue of the journal Health Education & Behavior, placed 200 women into five groups based on their attitudes about food. The women had an average age of 46, were well-educated (two-thirds had a four-year degree or higher) and 86 percent were white.

The researchers then compared the groups of women by measurements such as percentage of body fat, waist size and body mass index (BMI).

Those deemed to be “concerned about nutrition” (determined to eat well) and “creative cooks” (focused on food for their families) scored the lowest in the weight categories. “Impulsive eaters” and “guilt-ridden dieters” scored the highest, with “busy cooking avoiders” in the middle.

“Women in the middle group tend to lead busy lifestyles and are often preoccupied with other activities and responsibilities, with eating generally taking a back seat,” said Degeneffe, a research fellow at the University of Minnesota’s Food Industry Center.

Cynthia Sass, a registered dietitian and author in New York City, said the categories defined in the study “truly parallel what I see with my clients and women I talk to regarding how food and nutrition fit into their lives.”

“I have found that women who have a big responsibility to take care of their families appear to do less well at taking care of themselves, food-wise,” she said. In some cases, she said, food helps them to feel rewarded and cope with their lives.

She urges them to focus on their own needs “because taking better care of themselves will help them have the physical and emotional wellness they need to continue taking care of their families.”

Treating these kinds of women can be tough, said Lona Sandon, an assistant professor at the University of Texas Southwestern and national spokesperson for the American Dietetic Association. “Health and nutrition may be important to them, but convenience often wins,” she said. “It is very challenging to come up with solutions to help these women lose weight if they are not willing or able to give up something else in their life.”

Health Education & Behavior, a peer-reviewed journal of the Society for Public Health Education (SOPHE), publishes research on critical health issues for professionals in the implementation and administration of public health information programs. For information, contact Laura Drouillard at (202) 408-9804.

Sudo, N, et al. Relationship between attitudes and indicators of obesity for midlife women. Health Education & Behavior 36(6), 2009.

Source: Health Behavior News Service