CHICAGO, IL -- (April 7, 2009) -- Older adults with generalized anxiety disorder who received cognitive behavior therapy had greater improvement on measures of worry, depression and mental health than patients who received usual care, according to a study in the April 8 issue of JAMA.

Generalized anxiety disorder is common in late life, with prevalence up to 7.3 percent in the community and 11.2 percent in primary care. Late-life anxiety predicts increased physical disability, memory difficulties and decreased quality of life, according to background information in the article. Late-life anxiety is usually treated with medication, but associated risks (e.g., falls, hip fractures, memory problems) with some drugs and patient fears of adverse effects limit their usefulness. Two previous studies suggested benefits of cognitive behavior therapy in primary care for late-life GAD, but the studies were small and conclusions were limited. Older adults most often seek treatment for GAD in primary care.

Melinda A. Stanley, Ph.D., of Baylor College of Medicine, Houston, and colleagues conducted the first randomized clinical trial of CBT for late-life GAD in primary care to examine whether CBT would improve outcomes relative to enhanced usual care. The trial included 134 older adults (average age, 67 years) in two primary care settings, with treatment provided for 3 months. Assessments were conducted at the beginning of the trial, posttreatment (3 months), and over 12 months of follow-up, with assessments at 6, 9, 12 and 15 months. Patients were randomized to either CBT (n = 70), which included education and awareness, relaxation training, cognitive therapy, problem-solving skills training and behavioral sleep management; or EUC (n = 64), in which patients were telephoned biweekly during the first 3 months of the study by the same therapists to provide support and ensure patient safety. Therapists reminded patients to call project staff if symptoms worsened.

Levels of anxiety, worry, depression and physical/mental health quality of life were measured via various tests or surveys. The researchers found that CBT, compared with EUC, significantly improved worry severity, depressive symptoms and general mental health. In intention-to-treat analyses, response rates defined according to worry severity were higher following CBT compared with EUC at 3 months (40.0 percent vs. 21.9 percent).

"This study is the first to suggest that CBT can be useful for managing worry and associated symptoms among older patients in primary care," the authors write. "This study paves the way for future research to test sustainable models of care in more demographically heterogeneous groups."

HOUSTON -- (April 6, 2009) -- Certain ethnic groups may not be getting accurate estimates of disease risk when they try to determine obesity using the traditional body mass index scale, say researchers at Baylor College of Medicine and the University of Houston in a study in the current edition of British Journal of Nutrition.

DXA images are of two adults with the same BMI. While their weight and height may be similar, resulting in the same BMI, the person on the right has twice as much body fat as the person on the left. DXA images allow doctors to analyze bone density, lean mass and fat mass. Click the image to see a larger version.

"Our research shows that the number used to indicate weight category does not reflect the same amount of body fat for some races compared to others," said Dr. Molly Bray, associate professor of pediatrics - nutrition at the USDA/ARS Children's Nutrition Research Center at BCM and Texas Children's Hospital. "The results are consistent with other studies that say BMI is inexact and should be tailored to help target those at risk."

BMI is a formula that estimates a person's body fat using only his/her weight and height. The result is then used to determine weight categories. For example, 18.5 and below is considered underweight and between 18.6 and 24.9 is considered healthy. A person is overweight when their number falls between 25 and 29. Thirty and above is considered obese.

"This scale was created years ago and is based on Caucasian men and women," said Bray, who is also senior author of the study, "It doesn't take into account differences in body composition between genders, race/ethnicity groups, and across the lifespan."

In the current study, rather than using other potentially biased methods employed in the past as "gold standards" to examine body composition, researchers used dual-energy x-ray absorptiometry, which is a low dose x-ray known as DXA, to determine percent fat. DXA can be used to estimate bone density, lean mass and fat mass.

"It's important to break down the BMI numbers," Bray said. "Just because you weigh a certain amount doesn't necessarily mean you are overweight. Take, for example, an athlete who is very muscular and still weighs up to 300 pounds."

When the two results were compared, researchers found that the DXA estimate of percent fat of African American women was 1.76 percent lower for the same BMI compared to non-Hispanic white women. Since BMI is assumed to represent body fatness, an African American woman would not be considered overweight or obese until she reached a higher number than what is indicated by the current BMI standards. The opposite is the case for Hispanic, Asian and Asian-Indian woman. Their percent fat is higher by 1.65 percent, 2.65 percent and 5.98 percent, respectively. So they would be considered overweight or obese at amounts lower than what the BMI standards indicates. The results for men were similar.

"Right now non-Hispanic white women are not considered obese until they have a BMI of 30 or above. Based on our data in young adults, for Hispanic women the number would be around 28," said Bray. "For African American women the number to cross is around 32."

Bone mineral content, hydration state, and the density of lean mass found in different ethnic groups are some factors that account for the differences.

"These results demonstrate that body composition measures obtained from DXA can be used to more accurately define risk factors and provide better recommendations for the treatment and care for patients," said Bray.

The study participants were recruited from the TIGER (Training Intervention and Genetics of Exercise Response) study. It is designed to investigate how variation in DNA sequence may influence levels of body fatness and fitness.

Other researchers who took part in the study include Drs. Andrew S. Jackson, lead author of the study, and Brian K. McFarlin, both of the Department of Health and Human Performance at the University of Houston; Drs. Kenneth J. Ellis and Mary H. Sailors, both of the USDA/ARS Children's Nutrition Research Center at BCM and TCH; Dr. John Foreyt, professor of medicine, psychiatry and behavioral sciences at BCM.

Funding came from a grant from the National Institute of Health.

The paper can be found at http://journals.cambridge.org/action/displayJournal?jid=BJN.

HOUSTON -- (April 2, 2009) -- A particular nuclear hormone receptor called DAF-12 and molecules called microRNAs in the let-7 family form a molecular switch that encourages cells in the larvae of a model worm to shift to a more developed state, said a consortium led by researchers from Baylor College of Medicine (www.bcm.edu) in a report that appears online today in the journal Science.

As organisms go through the stages of life, hormones coordinate the changes. Nuclear receptors respond to hormones to coordinate stage transitions, but how they do so is not well understood.

From stage 2 to stage 3

“We knew that nuclear hormone receptors were involved in stage 2 to stage 3 transitions in Caenorhabditis elegans,” said Dr. Adam Antebi, associate professor in the Huffington Center on Aging at BCM and the report’s senior author. “Another class of molecules called microRNAs is also involved in that transition. We hypothesized that maybe if they are involved in the same process, one turns on the other.”

That turns out to be the case in C. elegans and may be true in more advanced organisms as well, he said.

Model worm enables studies

Scientists use the tiny worm called Caenorhabditis elegans to study such processes because it has a simple anatomy and life cycle. C. elegans develops from embryo through four larval stages into adulthood.

Each “stage” has specific programs of cell division, migration, differentiation and death that are crucial to the organism’s final development. Particular master regulators in the worm determine each stage transition and are responsible for organizing developmental time.

“Expression of the let-7 family of microRNAs is dependent on the nuclear receptor and its hormone,” Antebi said. “We can show in the worm and in cell culture that DAF-12 and its steroid hormone are directly activating these microRNAs.”

How transitions occur

But how does this cause stage transitions?

The tiny molecules called microRNAs work as switches to turn off other genes. In this case, the nuclear hormone receptor DAF-12 and its ligand turn on the microRNAs, which then turn off the earlier developmental “programming” of the cell (stage 2), allowing the later programming (stage 3) to take over.

Specifically, the microRNAs dial-back the activity of a protein called “hunchback,” which specifies that the cells are in stage 2. That enables stage 3 to start and development to continue.

Cancer insights

“We think this could also give insight into cancers,” Antebi said, “particularly those that are hormone-dependent, such as breast or prostate cancer. When worm skin cells go from stage 2 to stage 3 they reduce their cell proliferation. When they fail this transition, skin cells overproliferate (grow uncontrollably).”

It is known that both nuclear receptors and microRNAs play a role in human cancers. These studies could help bridge understanding of the effects of the two.

Development linked to environment

Antebi also thinks that this system links development to the environment. DAF-12 plays a role in a long-lived quiescent stage called the dauer diapause, which the worms enter in times of starvation and overcrowding.

“In good times, the DAF-12 steroid ligand is made, the microRNAs are turned on, and the worm goes through all stages of development to adult,” said Antebi. (A ligand is a molecule that binds to the receptor to form a biologically active complex.)

“In bad times, the ligand is not made and the nuclear receptor (DAF-12) causes the animals to go into the long lived dauer stage, shutting down the microRNAs and the developmental clock,” he said.

In this way, environmental signals actually affect the worm’s rate of development, and perhaps even its aging, said Antebi.

Others who took part in this work include Axel Bethke and Nicole Fielenbach of BCM, and Zhu Wang and David J. Mangelsdorf of The University of Texas Southwestern Medical Center in Dallas. Bethke is now with the University of Osnabruck in Germany.

Funding for this work came from the National Institutes of Health, the Ellison Medical Foundation, the Howard Hughes Medical Institute and the Robert Welch Foundation.

For more information on basic science research at Baylor College of Medicine, please subscribe to our From the Labs newsletter.

HOUSTON -- (April 1, 2009) -- Causes and consequences of small-for-gestational-age infants will be the topic of discussion in a public forum April 14 at The Health Museum of Houston.

The forum will feature Dr. Eric Eichenwald, associate professor of pediatrics at Baylor College of Medicine and medical director of the Texas Children's Hospital Newborn Center, and Dr. Kjersti Aagaard, assistant professor of obstetrics and gynecology at BCM.

Eichenwald and Aagaard will discuss the effects of small-for-gestational-age status on neonatal, childhood and adult outcomes, as well as influences on how genes are expressed.

Sponsored by BCM and Texas Children's, the event is part of the monthly "Evening with Genetics" lecture series organized by BCM's Department of Molecular and Human Genetics. The series offers current information regarding care, education and research about genetic disorders.

Small-for-gestational-age refers to newborn infants whose size and weight are considerably less than the average for babies of the same age.

The program is free and open to the public. It will be held at 7 p.m. at The Health Museum of Houston, 1515 Hermann Dr. For more information or to register, contact Susan Fernbach at 832-822-4182 or fernbach@bcm.edu.

Additional information can be found on upcoming seminars at http://www.bcm.edu/eveninggenetics/.

HOUSTON -- (March 27, 2009) -- The Center for Research on Women with Disabilities at Baylor College of Medicine is recruiting women with disabilities for a new Internet-based health promotion program called Garden of Wellness.

The program offers information on how women with disabilities can improve physical activity and nutrition, manage stress, use health care services effectively and deal with aging and disability.

“Internet-based interventions will help us reach so many more women who struggle to get out of their house due to limitations in transportation, child care, attendant care and all the health problems that accompany their disability,” said Dr. Margaret Nosek, professor of physical medicine and rehabilitation at BCM.

To qualify for the study, volunteers must be women at least 45 years of age, have access to a computer and Internet for about two to four hours per week and have a physical health condition that has limited daily activities for at least one year.

For more information about the study, call 713-523-0909 or 800-442-7693, or e-mail CROWD.