An estimated 4%-6% of children and adolescents in the United States are severely obese, and the prevalence appears to be on the uptick.
At the same time, existing treatments for the condition are limited in effectiveness and lack widespread availability, a nine-member writing group of experts led by Aaron S. Kelly, Ph.D., reported in a scientific statement from the American Heart Association.
"Severe obesity in young people has grave health consequences," said Dr. Kelly in a press statement. "It’s a much more serious childhood disease than obesity."
The condition "demands attention and clinical management, because if left unchecked, it will have a profound effect on those it afflicts and will place a significant economic and clinical services burden on the future health care system," the writing group cautionedonline Sept. 9 in Circulation. It emphasized that stakeholders at all levels "will need to work together to engage the growing problem of severe pediatric obesity."
The 17-page statement includes a recommendation to define children over age 2 as severely obese if they have either a body mass index that’s at least 20%higher than the 95th percentile for their sex and age, or a BMI score of 35 kg/mm2 or higher (Circulation 2013 Sept. 9 [doi:10.1161/CIR.0b013e3182a5cfb3]). According to estimates from the National Health and Nutrition Examination Survey dating back to 1999, 4%-6% of children and adolescents in the United States currently fall into this category. Those same data suggest that severe obesity is the fastest-growing subcategory of obesity in youth.
Dr. Kelly of the division of epidemiology and clinical research in the department of pediatrics at the University of Minnesota, Minneapolis, and his associates discussed numerous associated health risks from being severely obese as a child, in particular the mounting evidence from clinical and population-based studies regarding its link to the development of cardiovascular disease (CVD). "Importantly, obesity and CVD risk factors associated with obesity have been linked to early atherosclerosis in pathological studies of the coronary arteries and aorta in adolescents and young adults," the writing group stated.
Other associated health risks that threaten this subset of patients include hyperinsulinemia, insulin resistance, and prediabetes; obstructive sleep apnea syndrome; nonalcoholic fatty liver disease; musculoskeletal problems; depression and other psychosocial problems; and disordered eating.
Although data regarding the long-term risks of severe pediatric obesity are sparse, the authors noted, "it is well established that obese youth (probably because of the strong tracking of adiposity into adulthood) are more likely to have adverse levels of cardiovascular and metabolic risk factors later in life. Higher BMI is associated with tracking in the higher levels of both blood pressure and lipids in longitudinal pediatric cohort studies. Adolescents with a higher degree of obesity are also much more likely to demonstrate CVD risk factor clustering over time. Rate and degree of obesity development are also important."
The writing group characterized current treatment options for severe pediatric obesity as limited, as most standard approaches to weight loss are insufficient for this group. As for medications, orlistat is the only agent approved for weight loss in adolescents. The largest study of its use in adolescents reported a 2.4% reduction in BMI over the course of 12 months (JAMA 2005;293:2873-83). Other agents that have been studied for pediatric obesity include metformin and exenatide. To date, the "results have demonstrated that treatment elicits only modest reductions in BMI/weight and has relatively little impact on the cardiometabolic risk factor profile in obese youth," the experts wrote. Two weight loss medications recently approved by the Food and Drug Administration to treat obesity in adults, lorcaserin and the combination of phentermine and topiramate, have never been studied in children.
Dr. Kelly and his associates went on to note that bariatric surgery "has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage."
The scientific statement, which is endorsed by the Obesity Society, includes "a call to action" for innovative ways to "fill the gap between lifestyle/medication and surgery." Proposals include conducting more research on bariatric surgery’s effects and safety; evaluating the effectiveness of lifestyle modification interventions, including adherence to dietary and physical activity plans; funding research to find other useful interventions, including better drugs and medical devices; and recognizing severe obesity as a chronic disease requiring ongoing care and management.
"The task ahead will be arduous and complicated, but the high prevalence and serious consequences of severe obesity require us to commit time, intellectual capital, and financial resources to address it," the writing group concluded.