The emerging epidemic of obesity in children and adolescents is causing a serious public health concern. A multiphase and multidisciplinary approach is essential to contain the serious implications associated with obesity. A study recently published in the British Medical Journal reviews the causes and emerging treatments for obesity in childhood and adolescents.
Recent studies have shown an increase in prevalence of severe obesity in 2.5%-6% of children aged 2-19 years. This substantial increase in childhood obesity can be attributed to societal and environmental factors such as calorie-dense and processed food, and sedentary lifestyles, but genetics, by far, plays the most significant role in establishing body weight set point and dictates the physiologic responses to environmental moderators such as nutrition, activity, and other social behaviors. The hypothalamus plays a vital role in regulating body weight. Thus, hypothalamic dysfunction secondary to genetic, immunologic, inflammatory and traumatic causes leads to childhood obesity. Corticosteroid overproduction due to adrenal or pituitary conditions or exogenous administration can also cause obesity. Atypical antipsychotics also have greatly contributed towards childhood obesity.
Often, childhood obesity tracks into adulthood and contributes significantly to the development of cardiovascular and metabolic diseases. It also impacts social, psychological and academic development. Obese children are at a high risk of being bullied, discrimination, lower health-related quality of life, and impaired mental health. This study recently published in the British Medical Journal 2016 explores recent developments in our understanding of severe childhood obesity, underlying causes, and weight regulation. It also focuses on emerging medical and surgical treatments, reviewing the indications, limitations, and evidence behind their use.
PubMed, Medline, and Embase databases were searched for all studies in English that were conducted in a pediatric age group (0-18 years) from January 2010 to December 2015. Prioritization was given to systematic reviews and randomized control trials. Obesity is defined in the clinical setting by using body mass index (BMI, measured as kg/m2)—a calculation that allows for adjustment of weight on the basis of height and can be plotted on a growth chart for age and sex. Assessment of BMI remains the recommended approach to identify obesity in childhood and adolescence.
Current guidelines to treat obesity recommend a multidisciplinary approach including goal setting, physical exercise, and positive reinforcement. A few studies based on this lifestyle intervention showed that behavioral interventions for children and adolescents achieved modest reductions in BMI over the short-term, with improved efficacy in younger children. Drugs that affect nutrient processing or regulate hormones or appetite and satiety centers in the nervous system, can additionally be used to treat obesity along with behavioral changes. Orlistat reduces fat absorption by acting on gastric and pancreatic lipase enzymes but also leads to adverse effects like loose and oily stools with flatulence affecting compliance of the patients. It also may affect absorption of fat-soluble vitamins and cause an increase in gallstones. Metformin acts by affecting glucose metabolism, lipid oxidation, and central satiety. Evidence from randomized trials suggests that metformin is safe in achieving weight loss in children with obesity but the magnitude of its effect is small and durability of weight loss is questionable.
Other drugs like Lorcaserin, Topiramate, and Zonisamide control weight by affecting different aspects of the central nervous system but further studies are needed to evaluate them as potential treatments for obesity. Bariatric surgery is emerging as an important treatment option for adolescent obesity. It acts by reducing the size or bypassing the stomach, thereby mechanically restricting food intake. The gastric bands also affect the vagus nerve and promote satiety. Side effects include potential surgical risks and complications such as anastomotic leakage, infection, thromboembolism, and bleeding though these are more rarely reported (5-6%) in adolescent patients. The surgery-related weight loss also improved metabolic health, cardiovascular comorbidities, mental health and quality of life.
However, it does raise ethical and medical concerns that are unique to the pediatric population like short- and long-term effects on growth, nutrition, and mental health, as well as the ethics of consent in children with evolving capacity for decision-making. It is also noteworthy that these studies have largely focused on BMI outcomes that may not truly reflect on physical and psychological health of the individual. In conclusion, current evidence suggests that behavioural interventions, adjunctive drugs, and bariatric surgery can be effective in reducing weight but more research for patient-centered outcomes should be conducted to understand the personal effect of obesity treatment.
Written By: Dr. Shreyasi Sharma, MBBS