Print

Also Appearing in This Week’s Obesity Theme Issue

EMBARGOED FOR EARLY RELEASE: 10 A.M. (ET) TUESDAY, SEPTEMBER 18, 2012


Higher Amounts of Aerobic Exercise By Overweight Children Reduces Risk of Diabetes

Child obesity and overweight are epidemic among U.S. children, with a third of elementary school-aged children being overweight or obese. Childhood obesity is associated with a number of adverse conditions formerly thought to occur only in adults, including type 2 diabetes, according to background information in the article. “Previous studies in children have shown reduction in metabolic risk factors through exercise, but dose-response information needed to formulate evidence-based public health recommendations for children is not available.”

Catherine L. Davis, Ph.D., of the Medical College of Georgia, Augusta, and colleagues conducted a study to test the effect of different amounts of aerobic training on insulin resistance, fatness, visceral (abdominal) fat, and fitness in overweight, sedentary children. The randomized controlled trial was conducted from 2003 through 2007 and included 222 overweight or obese sedentary children (average age, 9.4 years; 42 percent male; 58 percent black). Children were randomly assigned to low-dose (20 min/day; n = 71) or high-dose (40 min/day; n = 73) aerobic training (5 day/week; average duration, 13 weeks) or a control condition (usual physical activity; n = 78). The pre-specified primary outcomes were post-intervention type 2 diabetes risk, as assessed by certain measures of insulin, aerobic fitness, percent body fat, and visceral fat.

The researchers found that reductions in the measure of insulin were greater in the high-dose aerobic training group and the low-dose group than the control group. Dose-response trends were also observed for body fat and visceral fat in the high- and low-dose vs. control groups. Effects in the high- and low-dose groups vs. control were similar for fitness.

“In conclusion, in this randomized controlled trial, 13 weeks of 20-or 40-min/day aerobic training resulted in improvement in diabetes risk as estimated by insulin resistance, fitness, and general and visceral adiposity [body fat] in sedentary overweight or obese children regardless of race or sex, with a dose-response gradient for insulin resistance and adiposity.”

(JAMA. 2012;308[11]:1103-1112. Available pre-embargo to the media at http://media.jamanetwork.com)

Editor’s Note: This work was supported by grants from the National Institutes of Health and a grant from the Salvador de Madariaga Program of the Spanish Ministry of Education and Science. All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported. This JAMA theme issue is being published the same week as the Obesity Society’s Annual Scientific Meeting.

Media Advisory: To contact Catherine L. Davis, Ph.D., call Toni Baker at 706-721-4421 or email tbaker@georgiahealth.edu.

 

# # #

Study Examines Long-Term Health Care Use Following Bariatric Surgery

“Bariatric surgery reduces weight and improves diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea. Long-term outcomes for surgically induced weight loss from the Swedish Obese Subjects study have demonstrated sustained weight loss, reduced incidence of diabetes, cardiovascular events, and cancer, as well as improved 10- to 15-year survival. Although there are many benefits from bariatric surgery, it is not known whether these translate to reduced long-term health care use,” according to background information in the article.

Martin Neovius, Ph.D., of the Karolinska Institute, Sweden, and colleagues from the Sahlgrenska Academy assessed the amount of health care obese patients used over 20 years after undergoing bariatric surgery, compared with obese patients who were conventionally treated. The Swedish Obese Subjects study is an ongoing, prospective, controlled intervention study conducted in the Swedish health care system that included 2,010 adults who underwent bariatric surgery and 2,037 contemporaneously matched controls recruited between 1987 and 2001. Inclusion criteria were age 37 years to 60 years and body mass index of 34 or higher in men and 38 or higher in women. Of the surgery patients, 13 percent underwent gastric bypass, 19 percent gastric banding, and 68 percent vertical-banded gastroplasty. Controls received conventional obesity treatment.

The relative weight changes at 20 years for those in the surgery group was a loss of 18 percent vs. a loss of 1 percent among those in the control group; the surgery group had a 44.1 lbs. greater weight loss than non-surgery controls.

The researchers found that “despite considerably greater and sustained weight loss than conventionally treated controls, surgically treated patients used more inpatient and nonprimary outpatient care during the 6-year period after the index date but not thereafter. Cost savings in the surgery group were seen for medications that treat diabetes and cardiovascular disease between year 7 and 20, resulting in lower overall drug costs during that period.”

(JAMA. 2012;308[11]:1132-1141. Available pre-embargo to the media at http://media.jamanetwork.com)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Media Advisory: To contact Martin Neovius, Ph.D., email Martin.Neovius@ki.se.

 # # #

 Bariatric Surgery Does Not Result in Statistically Greater Reduction in Sleep Apnea Compared to Conventional Weight Loss Program

“Obesity is a major risk factor for obstructive sleep apnea (OSA). The estimated prevalence of OSA in obese adults varies from 42 percent to 48 percent in men and 8 percent to 38 percent in women,” according to background information in the article. Individuals with OSA are at greater risk of stroke, cardiac disease, cognitive dysfunction, and impaired quality of life. Observational studies of major weight loss following bariatric surgery have suggested substantial remission of OSA symptoms. There have not been any randomized controlled trials comparing medically supervised weight loss with bariatric surgery as a treatment for OSA.

John B. Dixon, M.B.B.S., Ph.D., F.R.A.C.G.P., of Baker IDI Heart and Diabetes Institute and the Obesity Research Unit, Monash University, Melbourne, Australia, and colleagues conducted a randomized controlled trial comparing laparoscopic adjustable gastric banding (LAGB) with conventional weight loss therapy for the management of moderate to severe OSA in 60 obese patients (body mass index: >35 and <55). The patients had recently diagnosed (<6 months) OSA and an apnea-hypopnea index (AHI) of 20 events/hour or more. These patients had been prescribed continuous positive airway pressure (CPAP) therapy to manage OSA and were identified via accredited community sleep clinics. The trial was conducted between September 2006 and March 2009. Patients were randomized to a conventional weight loss program that included regular consultations with a dietitian and physician, and the use of very low-calorie diets as necessary (n = 30) or to laparoscopic adjustable gastric banding; n = 30). The primary outcome measure for the study was baseline to 2-year change in AHI on diagnostic polysomnography.

Patients lost an average of 11.2 lbs. in the conventional weight loss program compared with 61.3 lbs. in the bariatric surgery group. The researchers found that both groups had a significant decrease in total AHI between baseline and 2 years, with a decrease of 25.5 events/hour, from 65.0 events/hour to 39.5 events/hour in the surgical group; and a decrease of 14.0 events/hour, from 57.2 events/ hour to 43.2 events/hour in the conventional group. The between-group difference was -11.5 events/hour or percentage change in AHI of -17.9 percent. CPAP adherence did not differ between the groups.

“Comparing surgical and conventional weight loss therapy for the management of OSA demonstrated greater weight loss in the surgically treated group, however, this did not translate into significantly greater improvements in OSA,” the authors write. “While there is a clear overall response to weight loss, the individual effects are variable, incomplete, and appear to be related to modest weight loss. This study suggests caution be used in counseling patients about the expected benefits of weight loss for OSA, and that patients losing weight be assessed appropriately before ceasing effective therapy.”

(JAMA. 2012;308[11]:1142-1149. Available pre-embargo to the media at http://media.jamanetwork.com)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Media Advisory: To contact John B. Dixon, M.B.B.S., Ph.D., F.R.A.C.G.P., email john.dixon@bakeridi.edu.au.

# # #

 Viewpoints in This Week’s JAMA

 The Next Generation of Obesity Research – No Time to Waste

Griffin P. Rodgers, M.D., and Francis S. Collins, M.D., Ph.D., of the National Institutes of Health, Bethesda, Md., write that compared to previous health crises the U.S. has faced, “obesity may pose the most significant challenge yet because it involves changing approaches to 2 fundamental aspects of daily life: food consumption and physical activity. To have any chance of release from obesity’s ever-tightening grip, the nation will require broad-based efforts in every corner of society; homes, schools, community organizations, all levels of government, urban design, transportation, agriculture, the food industry, the media, medical practice, and, without question, biomedical research.”

The authors suggest that to help address this issue, more rigorous data are needed on what approaches can help achieve and maintain healthy body weights over the long term. There is also a need for more basic research aimed at expanding understanding of the molecular basis of obesity, and research focused on understanding the environmental risk factors for obesity. Behavioral and other kinds of research should also further explore strategies involving innovative technologies.

“While there are many key differences between the obesity epidemic and the health threats posed by tobacco use, infant mortality, and HIV/AIDS, the nation’s clinicians, researchers, policy makers, food producers, business owners, educators, community leaders, and citizens should consider what it took to make significant progress against those formidable foes. Can the United States again rise to the challenge and change its attitudes, policies, behaviors, and environments in some fundamental ways? The health of the next generation depends on the answer.”

(JAMA. 2012;308[11]:1095-1096. Available pre-embargo to the media at http://media.jamanetwork.com)

 

FDA Approval of Obesity Drugs – A Difference in Risk-Benefit Perceptions

Elaine H. Morrato, Dr.P.H., M.P.H., of the University of Colorado Denver, Aurora, and David B. Allison, Ph.D., of the University of Alabama at Birmingham, write that in the last decade, 3 obesity drugs were removed from the U.S. market, and until last month, only 1 new obesity drug has been approved since 1999. “Some observers question whether new obesity drugs are being held to a higher regulatory standard.” In this Viewpoint, the authors offer suggestions on how to improve the transparency of risk-benefit deliberations for obesity drugs, as well as other drugs that are used broadly in the population and that require Advisory Committee review.

“Reviewing drugs is an inherently challenging task. Consideration of the cognitive factors influencing risk-benefit deliberations may be a useful step toward making the review of obesity drugs more transparent to physicians and patients. The tendency to think dichotomously inherently makes balancing the potential risks against the potential benefits of drugs difficult, as does the inherent difficulty in adopting alternative perspectives (e.g., patient vs. society vs. regulator). Explicit discussions of this dichotomy and reminders to advisory board members of their charge may help to overcome these challenges for the good of prospective patients.”

(JAMA. 2012;308[11]:1097-1098. Available pre-embargo to the media at http://media.jamanetwork.com)

 

 

Cardiovascular Risk Assessment in the Development of New Drugs for Obesity

William R. Hiatt, M.D., of the University of Colorado School of Medicine, Aurora, and colleagues write that the U.S. Food and Drug Administration (FDA), Center for Drug Evaluation and Research, convened a meeting of the Division of Metabolism and Endocrinology Products in March 2012 to consider cardiovascular safety requirements for approval of new drugs to treat obesity. Because obesity is associated with excess cardiovascular risk and weight loss treatments could potentially mitigate that risk, it is important to assess the effect of these drugs on cardiovascular morbidity and mortality.” The authors examine the issue of evaluating cardiovascular risk for obesity drugs.

“The deliberations of the U.S. FDA Endocrinologic and Metabolic Drugs Advisory Committee provide insight into the challenges and recommendations for developing new antiobesity drugs. Key considerations include demonstrating that any degree of drug-induced weight loss is associated with short-term and longer-term clinical benefits. Assessment of cardiovascular safety has emerged as a major consideration for all new antiobesity drugs under current review. If there is a change in the regulatory approval process, it is likely the FDA will issue a revised guidance document for development of weight-loss products addressing these issues. At present, use of any new drugs that enter the market without long-term safety data should be limited to patients similar to those studied in the pivotal trials.”

(JAMA. 2012;308[11]:1099-1100. Available pre-embargo to the media at http://media.jamanetwork.com)

 Editor’s Note: Please see the articles for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.