Acute complications of childhood obesity
- Acute complications of childhood obesity include type 2 diabetes, hypertension, hyperlipidemia, accelerated growth and bone maturation, ovarian hyperandrogenism and gynecomastia, cholecystitis, pancreatitis, and pseudotumor cerebri. Fatty liver is common; rarely, patients develop cirrhosis and renal disease (focal glomerulosclerosis). Sleep apnea and sleep-disordered breathing are common in children and adolescents with obesity; in some cases, the apnea is accompanied by neurocognitive dysfunction. Tonsillectomy and adenoidectomy and/or bilevel positive airway pressure/continuous positive airway pressure (BIPAP/CPAP) may be beneficial in patients with reduced oxygenation or carbon dioxide retention.
- Orthopedic disorders. Numerous orthopedic disorders, including genu valgum, slipped capital femoral epiphysis, and tibia vara, are observed more commonly in children with obesity. Excess weight in young children can cause bowing of the tibia and femurs; the resulting overgrowth of the proximal tibial metaphysis is called Blount disease.
- Liver and gallbladder dysfunction. Evidence of liver dysfunction, with elevated plasma concentrations of transaminases, is observed in 20% of children with obesity; the liver dysfunction most commonly reflects hepatic steatosis, but cirrhosis may develop in rare instances. Vitamin E supplements may be effective in reversing this so-called steatohepatitis, suggesting that the disorder reflects a relative state of vitamin E deficiency. Cholelithiasis is more common in adults with obesity than in adults with normal weight. Although gallstones are unusual in childhood, nearly one half of all cases of cholecystitis in adolescents are associated with obesity. Cholecystitis may be even more common during rapid weight loss, particularly with very controlled–energy diets.
- Psychologic complications. Emotional and psychosocial sequelae are widespread. Anecdotal evidence suggests that depression and eating disorders are common in children and adolescents referred to obesity clinics. Prejudice and discrimination against individuals with obesity are ubiquitous within US culture; even young children have been found to regard their peers who have obesity in negative ways. Social isolation, peer problems, and lower self-esteem are frequently observed.
- Cardiovascular and endocrine complications. Obesity during childhood and adolescence is associated with numerous cardiovascular risk factors, including hyperinsulinism and insulin resistance, hypercholesterolemia, hypertriglyceridemia, reduced levels of high-density lipoprotein (HDL), and hypertension. A hallmark of insulin resistance is acanthosis nigricans, the presence of which indicates an increased risk of type 2 diabetes. Adolescent girls with obesity also demonstrate a hyperandrogenic profile, consisting of elevated serum concentrations of androstenedione, dehydroepiandrosterone-sulfate (DHEA-S), and testosterone, as well as reduced levels of sex hormone–binding globulin. The clinical picture resembles that of polycystic ovary syndrome (PCOS). The excess androgens are of adrenal and ovarian origin and may be related, at least in part, to increased serum concentrations of insulin and insulin growth factor 1 (IGF-I).
- Among sexually mature adolescents, changes in serum lipids and androgens seem to correlate more strongly with body fat distribution than with absolute weight. Thus, adolescents with central obesity (ie, android or abdominal fat pattern) are more likely to manifest these cardiovascular risk factors than individuals with peripheral obesity (ie, gynoid or gluteal pattern). In prepubertal children, however, the cardiovascular risk factors correlate better with body weight than with body fat distribution. The increasing prevalence of obesity in childhood and adolescence, accompanied by insulin resistance, appears to explain the increasing incidence of type 2 diabetes in adolescents, particularly in minority populations.
- Studies indicate that obese children with nonalcoholic fatty liver disease may be at increased risk for atherosclerosis.
Long-term complications of childhood obesity
- Obesity during childhood and adolescence is associated with an increased risk of obesity during adulthood, with its attendant long-term health risks. This increased risk appears most pronounced for adolescent males with moderate to severe obesity. The long-term implications of obesity during infancy and early childhood on subsequent health are less clear. In general, the proportion of children with obesity who have obesity as adults increases with increased age at onset of obesity, such that 26-41% of preschoolers with obesity have obesity as adults, compared with 42-63% of school-aged children. Additionally, the higher the degree of obesity during childhood, the higher the risk of adult obesity.
- Individuals aged 18 years with a body mass index (BMI) at or above the 95th percentile have a 66-78% risk of being overweight at age 35 years. A recently published study reported that at age 18 years, a BMI of 35 or greater was independently associated with an increased risk of lower extremity edema, walking limitation, polycystic ovary syndrome, abnormal kidney function, asthma, obstructive sleep apnea, and type 2 diabetes.
- Epidemiologic data, although limited, indicate that adolescent obesity is associated with increased morbidity and mortality in later life. Accordingly, the dramatic increase in the prevalence of type 2 diabetes among adolescents with obesity is likely to be accompanied by a host of diabetic-related complications in adulthood and a reduction in life span. Although obesity, per se, is associated with a heightened risk of morbidity related to abnormalities in glucose homeostasis, recent data indicate that the rate of increase in BMI during adolescence may also represent a significant risk factor for diabetes.
- Cardiovascular disease. An increased risk of death from all causes and from coronary artery disease (CAD) has been consistently observed in males, but not in females, who had obesity during adolescence. In a follow-up of the Harvard Growth Study, the risk of morbidity from CAD and atherosclerosis was increased among men and women who had been overweight (BMI > 75th percentile) as teenagers. The trend towards higher BMI values among adolescents in the US has also been associated with increases in left ventricular mass, when compared to similar cohorts in earlier generations, further suggesting that early obesity increases the long-term risk for development of cardiac disease.
- Mangner et al conducted a study to assess geometric and functional changes of the heart in obese compared with nonobese children and adolescents. The authors found thicker left ventricular (LV) walls and an increased LV mass, as well as impaired measures of systolic function, among the obese children when compared with nonobese children. The authors also reported no difference in ejection fractions between the obese and nonobese children, but the average LV strain, strain rate, and displacement, which are markers of LV longitudinal function assessed by 2D speckle-tracking echocardiography (2D-STE), were significantly impaired among the obese children. The results of this study demonstrate that childhood obesity is associated with significant changes in myocardial geometry and function, indicating an early onset of potentially unfavorable alterations in the myocardium.
- Gout and colorectal cancer. Gout and colorectal cancer increased among men who had obesity as adolescents, and arthritis increased among women who had obesity as adolescents. Many of these adverse health outcomes appear to be independent of adult weight, suggesting a direct effect of adolescent obesity on adult health and mortality.
- Psychosocial dysfunction. Psychosocial dysfunction in individuals who have obesity in childhood and adolescence is a serious concern. Among teens and young adults who were tracked after 7 years, overweight females were found to have completed less schooling, were less likely to have married, and had higher rates of household poverty compared with their non-overweight peers. For overweight males, the only adverse outcome was a decreased likelihood of being married.