[show abstract][hide abstract] ABSTRACT: Surgical treatment of extreme obesity may be appropriate for some adolescents. We hypothesized that surgical weight loss outcomes may differ by preoperative level of extreme obesity (body mass index [BMI] > or=99th percentile).
A longitudinal assessment of clinical characteristics from 61 adolescents who underwent laparoscopic Roux-en-Y gastric bypass at a single pediatric center from 2002 until 2007 was performed. Patients were categorized into 1 of 3 preoperative BMI groups: group 1, BMI = 40.0 to 54.9 (n = 23); group 2, BMI = 55.0 to 64.9 (n = 21); group 3, BMI = 65.0 to 95.0 (n = 17). Changes in BMI and cardiovascular risk factors between baseline and year 1 were evaluated using repeated-measures mixed linear modeling.
BMI in the overall cohort at baseline (60.2 +/- 11 kg/m(2)) decreased by 37.4% at 1 year after surgery (P < .001). Percent BMI change varied little by preoperative BMI groups (-37.2%, -36.8%, and -37.7% for groups 1, 2, and 3 respectively; P = .8762). The rate of change in absolute BMI units significantly varied by preoperative BMI class (group x time interaction, P < .0001), with 1-year nadir BMI values for groups 1, 2, and 3 falling to 31 +/- 4 kg/m(2), 38 +/- 5 kg/m(2), and 47 +/- 9 kg/m(2), respectively. One year after surgery, only 17% of patients achieved a nonobese BMI (<30 kg/m(2)). Significant improvements in systolic and diastolic blood pressure (P < .0001), fasting insulin (P < .0001), total cholesterol (P = .0007), and triglyceride levels (P < .0001) were seen after surgery irrespective of baseline BMI class. Mean albumin levels remained normal despite significant caloric restriction and weight loss.
Laparoscopic gastric bypass resulted in improvement or reversal of cardiovascular risk factors and resulted in a decrease in BMI of approximately 37% in all patients, regardless of starting BMI, 1 year after surgery. The timing of surgery for adolescent extreme obesity is an important consideration, because "late" referral for bariatric surgery at the highest of BMI values may preclude reversal of obesity.
The Journal of pediatrics 09/2009; 156(1):103-108.e1. · 4.02 Impact Factor
[show abstract][hide abstract] ABSTRACT: An increasing number of young people are developing severe obesity with adult-like co-morbidities and undergoing bariatric surgery. Although a number of studies have described major weight loss after bariatric surgery, none have examined the proportions of lean body and fat mass lost or the potentially more important issue of changes in regional fat mass distribution after laparoscopic gastric bypass surgery.
Five morbidly obese females (mean age 18) were evaluated by standard anthropometric measures and dual energy x-ray absorptiometry at baseline and 1 year after bariatric surgery. The mean and SD values for the anthropometric and dual energy x-ray absorptiometry body composition variables were calculated, and the differences were evaluated using paired t tests.
Significant body mass index and weight loss were seen in all subjects at 1 year, with the percentage of excess weight loss at 63.4%. Overall fat mass loss exceeded lean mass loss by threefold in this cohort (P <.01), demonstrating the relative sparing of lean mass. Their waist circumference also decreased significantly. Using dual energy x-ray absorptiometry analysis, the vast majority (83%) of central mass loss consisted of adipose tissue. Central fat loss significantly exceeded peripheral fat loss by 1.6-fold (P = .03).
These results have demonstrated the preferential loss of central adiposity in morbidly obese young women after 1 year of surgical weight loss and may be more informative than anthropometric measurements alone. Given the association between central adiposity and the risk of subsequent cardiovascular disease, these results are suggestive of reduced cardiac risk.
Surgery for Obesity and Related Diseases 01/2007; 3(2):153-8. · 4.12 Impact Factor