IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read
Childhood obesity: Understanding the causes, beginning the discussion; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to
www.aapa.org and searching for keyword
JAAPA post-tests. All others may complete and submit the post-test online at no charge at
www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.
KEY POINTS
■ Unmanaged obesity in children has the potential to cause significant physiologic and psychosocial complications that can lead to negative health consequences in adulthood.
■ No exact guidelines exist for when to start treatment. Because obesity can have such negative consequences, a wait-and-see approach is strongly discouraged.
■ Maintaining current body weight while the child continues to grow should be the goal for the large majority of obese children. Only in children with severe obesity should weight loss be encouraged.
■ Only adolescents who have not lost weight through lifestyle modifications should be considered for medication use and even then only when the adolescent has other comorbidities and is continuing to adhere to the previously discussed diet and exercise interventions.
An estimated 16.9% of children 2 to 19 years old in the United States are obese.
1 In addition, the number of overweight and obese children has increased in almost all industrialized countries worldwide and in several lower-income countries.
2 The epidemic of obesity is linked to a rise in other serious diseases and disorders in children, including insulin resistance, hypertension, cardiovascular disease, hyperlipidemia, and poor self-esteem.
3 Given the increasing prevalence of childhood obesity and its related disorders, as well as the growing emphasis on exercise and proper nutrition in the medical literature and the media, clinicians must take an active role in recognizing, preventing, and managing childhood obesity.
COMORBIDITIES OF CHILDHOOD OBESITY
Approximately 80% of 10- to 15-year-olds who are overweight become obese adults by the age of 25 years.4 Obesity in children has the potential to cause significant physiologic and psychosocial complications that, if not managed in childhood, will lead to negative health consequences in adulthood.3 Physical complications can involve the cardiovascular, endocrine, GI, musculoskeletal, nervous, and respiratory systems. This article discusses the consequences and comorbidities of childhood obesity, treatment strategies, and when referral should be made.
Cardiovascular consequences As a result of the increase in childhood obesity leading to adult obesity, the prevalence of coronary heart disease (CHD) is estimated to increase 5% to 16% by 2035, with more than 100,000 cases of CHD attributed to the predicted increase in obesity.5 Obesity predisposes humans to changes in both cardiac structure and hemodynamics.6 Combined with excessive adiposity, obesity causes increased blood volume and cardiac output and can lead to cardiomyopathy. Two of the most common cardiac comorbidities of childhood obesity are dyslipidemia and hypertension.
According to results of the National Health and Nutrition Examination Survey (NHANES) for 1999 to 2006, the prevalence of dyslipidemia in children 12 to 19 years old was 20.3%.7 Typically, in obese children, serum low-density lipoprotein cholesterol (LDL-C) and triglycerides are increased and high-density lipoprotein cholesterol (HDL-C) levels are decreased.8 The proposed mechanism of dyslipidemia in obese children is an increase in free fatty acids produced by visceral adipocytes and hyperinsulinemia that promotes LDL-C and triglyceride synthesis by the liver.8 Fasting lipid profiles should be obtained every 2 years starting at age 10 years in patients whose body mass index (BMI) is in the 85th percentile or higher, regardless of risk factors.6 More information on specific levels and treatment can be found in Table: Comorbidities of childhood obesity and their findings, diagnostic workup, and treatment in the online version of this article. The mainstay of treatment for dyslipidemia is diet and exercise; however, appropriate referral should be made if conservative measures are not effective.9
Although hypertension is relatively rare in children, obese children have a threefold higher risk of hypertension than nonobese children.10 Contributing factors for hypertension in an obese child include hyperactivity of the sympathetic nervous system, insulin resistance, and abnormalities in vascular structure and function.10 Diagnosis of hypertension in children is based on BP tables that are adjusted for age, gender, and height.10 Hypertension is considered when a child has three systolic or diastolic BP readings above the 95th percentile.10 Treatment of hypertension in children should be aimed at behavioral approaches, such as diet and exercise, followed by medication in more refractory cases.10
While metabolic syndrome is common in obese adults and criteria for diagnosis in adults exist (Table 1), there are currently no criteria to diagnose metabolic syndrome in children.11,12 However, using modified adult criteria, the overall prevalence of metabolic syndrome is 38.7% in moderately obese children and 49.7% in severely obese children.11 Treatment consists of addressing dyslipidemia, hypertension, and type 2 diabetes mellitus (T2DM).6
Endocrine complications Because sex hormone-producing enzymes are expressed in adipose tissue, excess central adiposity can lead to high androgen activity or hyperandrogenemia.6 Up to 50% of free testosterone is derived from fat in young women.6 Hyperandrogenemia and abdominal obesity lead to hyperinsulinemia and insulin resistance, which stimulates androgen and estrogen production by the adrenal glands and the ovaries.6 In addition, lower concentrations of sex hormone-binding globulin (SHBG) in obese females lead to further increases in the levels of free testosterone.6 This increase in testosterone can result in menstrual abnormalities, such as amenorrhea, metrorrhagia, and polycystic ovary syndrome, in obese adolescent girls.6 Obese girls who experience hormone imbalance should be referred to a specialist in order to preserve fertility.9