News Briefs from the Endocrine Society

Low Vitamin D Levels May Contribute to Development of Type 2 Diabetes

A recent study of obese and nonobese children found that low vitamin D levels are significantly more prevalent in obese children and are associated with risk factors for type 2 diabetes. This study was accepted for publication in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

High rates of vitamin D deficiency have been found in obese populations, and past studies have linked low vitamin D levels to cardiovascular disease and type 2 diabetes. The mechanisms by which obesity and its comorbidities are related to vitamin D deficiency are not fully known. This new study examined associations between vitamin D levels and dietary habits in obese children, and tested whether there were correlations between vitamin D levels and markers of abnormal glucose metabolism and blood pressure.

“Our study found that obese children with lower vitamin D levels had higher degrees of insulin resistance,” said lead study author Micah Olson, MD, of the University of Texas Southwestern Medical Center in Dallas . “Although our study cannot prove causation, it does suggest that low vitamin D levels may play a role in the development of type 2 diabetes.”

In this study, researchers measured vitamin D levels, blood sugar levels, serum insulin, BMI, and blood pressure in 411 obese subjects and 87 control nonoverweight subjects. Study participants were also asked to provide dietary information including daily intake of soda, juice, and milk; average daily fruit and vegetable intake; and whether they routinely skipped breakfast.

“Poor dietary habits such as skipping breakfast and increased soda and juice intake were associated with the lower vitamin D levels seen in obese children,” said Olson. “Future studies are needed to determine the clinical significance of lower vitamin D levels in obese children, the amount and duration of treatment necessary to replenish vitamin D levels in these children and whether treatment with vitamin D can improve primary clinical endpoints such as insulin resistance.”

Other researchers working on the study include Naim Maalouf, Jon Oden, Perrin White, and Michele Hutchison of the University of Texas Southwestern Medical Center.

The article, “Vitamin D Deficiency in Obese Children and Its Relationship to Glucose Homeostasis,” appears in the January 2012 issue of JCEM.

Nervous System Activity May Predict Successful Weight Loss

A recent study of obese volunteers participating in a 12-week dietary weight-loss program found that successful weight losers had significantly higher resting nerve activity compared to weight-loss resistant individuals. The study was accepted for publication in JCEM.

The sympathetic nervous system is widely distributed throughout the body and subconsciously regulates many physiological functions, including the control of resting metabolic rate and the dissipation of calories after food intake. The present study examined the relationship between activity of the sympathetic nervous system and weight-loss outcome in a group of obese individuals on a low-calorie diet intervention program.

“We have demonstrated for the first time that resting muscle sympathetic nerve activity (MSNA) is a significant independent predictor of weight-loss outcome in a cohort of overweight or obese subjects,” said lead study author Nora Straznicky, PhD, of the Baker IDI Heart & Diabetes Institute in Melbourne, Australia. “Our findings provide two opportunities. First, we may be able to identify those persons who would benefit most from lifestyle weight-loss interventions such as dieting. Secondly, the findings may also help in developing weight-loss treatments through stimulating this specific nervous activity.”

In this study, researchers examined 42 overweight or obese subjects who had participated in dietary-lifestyle intervention trials that cut their daily caloric intake by 30% for 12 weeks. MSNA was measured by microneurography, a process involving the insertion of metal microelectrodes into nerve fascicles (a bundle of nerve fibers). Researchers found that weight loss was independently predicted by baseline resting MSNA.

“We also found that successful weight losers demonstrated large increases in nerve activity following a carbohydrate test meal, whereas the responses were completely blunted in weight-loss resistant subjects,” said Straznicky. “Our findings suggest a significant contribution of subconscious nervous system activity to the success of dietary weight loss.”

Other researchers working on the study include Nina Eikelis, Paul Nestel, John Dixon, Tye Dawood, Mariee Grima, Carolina Sari, Markus Schlaich, Murray Esler, Alan Tilbrook, Gavin Lambert and Elisabeth Lambert of Baker IDI Heart & Diabetes Institute.

The article, “Baseline sympathetic nervous system activity predicts dietary weight loss in obese metabolic syndrome subjects,” appears in the February 2012 issue of JCEM.

Society Calls for Public Policy Changes to Combat Pediatric Obesity Epidemic

On Dec. 5, 2011, the Endocrine Society issued a position statement supporting policies that bring together doctors and other health-care providers, family, schools, and the community to combat pediatric obesity through education and encouragement of lifestyle modifications.¹

Although obesity rates vary among different ethnic groups, an estimated 17% of US children aged 2 to 19 years are overweight or obese. Weight gain may increase the risk of developing diabetes, heart disease, stroke, liver disease, and reproductive disorders. Overweight children are more likely to be overweight or obese as adults, and the associated comorbidities are often prolonged or exacerbated in adulthood.

“To effectively combat the pediatric obesity epidemic in the United States, endocrinologists, primary care physicians, schools and parents must work together to educate and encourage lifestyle modifications,” said Janet E. Hall, MD, president of the Endocrine Society. “We also urge Congress to enact legislation that increases the availability of healthy, high-fiber foods like fruits and vegetables, and fat-free and low-fat dairy products in schools and communities.”

Specifically, the Endocrine Society supports the following positions:

• Increase research funding for new prevention and treatment options for childhood obesity;

• Enact legislation for better access to low-sugar, high-fiber food and drinks in schools and communities;

• Ensure proper evaluation and treatment of overweight and obese patients and provide incentives for physicians to allow for a greater role in the care of these patients;

• Offer incentives for the development of communities that provide the opportunity for adequate and safe physical activity; and

• Develop a council under the US Department of Agriculture or in the Department of Health and Human Services made of physicians, nurses, registered dieticians and business leaders to monitor industrial food development, commercialization and nutrition in schools.

In 2008, the Endocrine Society published its clinical guidelines, titled “Prevention and Treatment of Pediatric Obesity.”² The guidelines were developed after an extensive review of the best human research studies related to the diagnosis, treatment, and prevention of pediatric obesity and was written to help physicians who are evaluating and treating obese children and adolescents.

New Fact Sheet Explains Causes of Vaginal Atrophy and Describes Treatment Options

The Hormone Foundation has published a new bilingual (English and Spanish) fact sheet for women that defines vaginal atrophy and outlines vaginal and urinary symptoms. It explains the causes of vaginal atrophy, including natural or induced menopause, breast-feeding, and the use of estrogen-lowering medications. The fact sheet assures women that vaginal atrophy is treatable and describes over-the-counter and estrogen-based treatment options. It also describes techniques to relax overactive pelvic muscles that cause pain during intercourse.

The fact sheet can be found online at http://www.hormone.org/Resources/upload/Vaginal-Atrophy-Bilingual-WEB.pdf.

Founded in 1916, the Endocrine Society is the world’s oldest, largest, and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, the Endocrine Society’s membership consists of over 14,000 scientists, physicians, educators, nurses, and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the society and the field of endocrinology, visit our site at www.endo-society.org; follow us on Twitter at https://twitter.com/#!/EndoMedia; or contact us at 8401 Connecticut Avenue, Ste. 900, Chevy Chase, MD 20815 USA

Notes

1. Endocrine Society. Position statements [Web page]. http://www.endo-society.org/advocacy/policy/index.cfm.

2. Endocrine Society. Prevention and Treatment of Pediatric Obesity [online document]. http://www.endo-society.org/guidelines/final/upload/FINAL-Standalone-Pediatric-Obesity-Guideline.pdf.