The prevalences of several risk factors and diseases are dramatically increased in obesity. In contrast, considerable inconsistencies have been reported for the relationship of obesity to the incidence of cardiovascular disease and total mortality. Suggested reasons for these inconsistencies have been confounders and surrogate risk factors, but the single most important cause is that far-reaching conclusions have been drawn from small short-term studies. Several large studies have recently proven that the incidence of cardiovascular disease is increased in obesity. Correct classification of obesity and its subgroups is also of great importance. Visceral obesity constitutes one subgroup at high risk. It seems possible to link diabetes, hypertriglyceridemia, reduced fibrinolysis, and hypertension to elevated portal free fatty acid concentrations because of an increased visceral adipose tissue depot. The quantitation of visceral adipose tissue has been improved by techniques based on computed tomography (CT) and by CT-calibrated anthropometric methods. Results from controlled intervention studies of obesity are entirely lacking but one such study has been started.
All large prospective studies (n greater than 20,000) and several smaller studies have found that severe obesity [body mass index (BMI) greater than or equal to 35 kg/m2] is associated with approximately a twofold increase in total mortality and in a severalfold increase in mortality due to diabetes, cerebro-, and cardiovascular disease, and certain forms of cancer. Studies that have not been able to confirm this have been small and/or short term, have failed to control for smoking or early mortality, have controlled for intermediate risk factors in an inappropriate way, or have a reduced internal validity due to misclassification biases. As compared with BMI, abdominal obesity is a stronger predictor of mortality in most studies available. The incidence of sudden death unexplained by autopsy may be up to 40 times higher in severely obese subjects as compared with the general population. A small weight increase since the age of 18 is associated with a decreased risk whereas weight increases greater than 10 kg are associated with an increased mortality. The total mortality ratio for severe obesity decreases from 55 y of age and is not detectable above 80 y of age. Studies lacking adequate control groups indicate that a sustained weight loss may induce a reduced mortality but results from controlled intervention studies are so far not available.
The prevalence of obesity among adolescents has increased and we lack effective treatments.
To determine if gastric bypass is safe and effective for an unselected cohort of adolescents with morbid obesity in specialized health care.
Intervention study for 81 adolescents (13-18 years) with a body mass index (BMI) range 36-69 kg?m(-2) undergoing laparoscopic gastric bypass surgery in a university hospital setting in Sweden between April 2006 and May 2009. For weight change comparisons, we identified an adult group undergoing gastric bypass surgery (n=81) and an adolescent group (n=81) receiving conventional care.
Two-year outcome regarding BMI in all groups, and metabolic risk factors and quality of life in the adolescent surgery group.
Two-year follow-up rate was 100% in both surgery groups and 73% in the adolescent comparison group. In adolescents undergoing surgery, BMI was 45.5 ± 6.1 (mean ± s.d.) at baseline and 30.2 (confidence interval 29.1-31.3) after 2 years (P20 mU?l(-1)) was present in 70% of the adolescent surgery patients, which was reduced to 0% at 1 year and 3% at 2 years. Other cardiovascular risk factors were also improved. Two-thirds of adolescents undergoing surgery had a history of psychopathology. Nevertheless, the treatment was generally well tolerated and, overall, quality of life increased significantly. Adverse events were seen in 33% of patients.
Adolescents with severe obesity demonstrated similar weight loss as adults following gastric bypass surgery yet demonstrating high prevalence of psychopathology at baseline. There were associated benefits for health and quality of life. Surgical and psychological challenges during follow-up require careful attention.