May 2005
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IN THIS ISSUE

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Don't miss The Endocrine Society's 87th Annual Meeting, ENDO 2005, in San Diego, CA, Saturday, June 4 through Tuesday, June 7. Information, including details regarding press conferences and other media events planned for the meeting, is available online at http://www.endo-society.org/media/pressroom.cfm

What's New in Obesity Research? [RETURN TO TOP]

Coming this month in the The Journal of Clinical Endocrinology & Metabolism (JCE&M):

African American Children at Higher Risk of Becoming Overweight

Concerns about overweight and at risk of overweight among children have dominated health-related news in the past few years and have inspired researchers to wonder if ethnicity impacts the risk of becoming overweight. In the study "Onset of Overweight During Childhood and Adolescence in Relation to Race and Sex," researchers analyzed data on more than 900 children observed prospectively from the Indianapolis area and conducted a survival analysis, comparing the time to overweight by both race and gender. No gender difference was revealed. However, the study indicated that African American children were at a higher risk for becoming overweight than Caucasian children - even after adjustments were made for family income, birth weight and parents' level of education. This study was the first ever to report a significant difference in the age of emergence of the risk for overweight between races, with risk occurring much earlier in African American children. The exact age when overweight begins and how it manifests remain unknown to researchers despite the fact that this information can be essential for early prevention. Overall, the scientists encourage further investigation into race-specific timing of interventions and overweight prevention measures.

Breakthrough discoveries addressing childhood overweight will be presented at ENDO 2005 in June. For more information, please contact media@endo-society.org

Brain Composition: Does Leptin Regulate More Than Body Weight and Metabolism?

Leptin is a protein hormone that plays an important role in regulating body weight, metabolism and reproductive function. A new study - "Effect of Leptin Replacement on Brain Structure in Genetically Leptin-Deficient Adults" - explores the possible role of leptin on brain composition and weight. Researchers identified an adult study population with a recessive mutation in the obesity (ob) gene - a population that is both deficient in leptin and morbidly obese. Relying on findings from previous basic research in mice, the study investigators hypothesized that leptin replacement therapy would result in changes in the brain composition of the human study population. Magnetic resonance images (MRI) of the brain were taken at baseline, and again six and 18-months following the start of the leptin replacement treatment, at which point increases in gray matter tissue concentration were noted. These findings suggest that leptin may regulate more than just feeding behavior and endocrine function. It may have sustained effects on tissue composition in the human brain. Investigators call for more research into the spectrum of leptin's influence on the human body among populations with the ob gene mutation.

Bone Mineral Density: Parameters That May Impact Your Bone Health as You Age

Leptin is the protein hormone that regulates body weight and metabolism. Insulin is the polypeptide hormone that specifically regulates the metabolism of carbohydrates and fats, especially the conversion of glucose to glycogen. In the study "High Plasma Leptin is Not Associated with Higher Bone Mineral Density in Insulin Resistant Premenopausal Obese Women," researchers aimed to determine the impact of both leptin and insulin on bone mineral metabolism and calciotropic hormones. The study population included 48 obese premenopausal women, 28 of whom were insulin resistant and 20 of whom were insulin sensitive. The researchers concluded that there was a dichotomy in the impact of body composition parameters, insulin and leptin levels on bone mineral density in obese individuals. The interaction between the endocrine system, which regulates metabolism, and bone is extremely complex and seems to vary depending upon central and local resistance to insulin and leptin levels. Researchers believe this new study provides important new information that will help further shed light on the relation between the adipogenic hormones (leptin and insulin) and bone mineral metabolism.

Coming this month in Endocrinology:

Food Choice and Its Impact on Stress Response

In most species, the hypothalamic-pituitary-adrenal axis (HPA axis), a part of the neuroendocrine system, controls reactions to stress and stressors. Past study has revealed that rats given the choice of eating highly pleasurable calories (such as concentrated sucrose/sugar solutions) or lard (fat) exhibit reduced responsitivity to stressors in their environment, while rats fed high-fat diets withno choice have normal or improved responses to stressors in their environment. In the study "Choice of Lard, But Not Total Lard Calories, Damps ACTH Responses to Restraint," researchers attempted to identify the role food choice plays in stress response. In adult male rats, investigators compared stress response after 1) rats chose a food mixture composed of lard+chow (50-60 percent lard), 2) hadno choice but to eat a 50 percent lard+chow mixture, or 3) hadno choice but to eat chow-only. The study found that choice of eating high-density calories strongly reduces responses to stress and that insulin may act through sites in brain to hamper stress responses. The implications of this basic research on the role to the human population have yet to be determined, however, researchers presume that these findings may have profound implications for the current epidemic of obesity in humans who live in developed countries.

See these studies and more in the upcoming issues of JCE&M and Endocrinology from The Endocrine Society. To interview an author or to obtain a copy of any of the studies discussed above, contact media@endo-society.org

Other Happening/Events [RETURN TO TOP]

If you have any questions about this issue of The Endocrine Edge or The Endocrine Society, please contact media@endo-society.org.

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Exciting News From The Endocrine Society: ENDO 2005
The Endocrine Society is pleased to announce that all ENDO 2005 press are invited to attend a day-long Forum on Endocrine Disrupting Chemicals. This workshop will feature prominent endocrine investigators presenting the most recent discoveries on how hormonally active compounds in food, drinking water and the environment are increasingly linked to endocrine-related dysfunctions. Data examining fetal exposure to endocrine disrupting chemicals and its association with the development of adult disease - particularly infertility, obesity, breast and prostate cancer - will also be presented.

A limited supply of hardcopy editions of the 2005 edition of The Endocrine Society Weighs In: A Handbook on Obesity in America may be available. Please contact Tadu Yimam at media@endo-society.org for more information.