ORLANDO — Bariatric surgery produces rapid, dramatic improvements in obese adolescents, but after the first 6 months post surgery these patients appear to hit a wall and further gains in their clinical status usually do not occur, according to a follow-up study of 44 patients.
“There is generally a plateau [of weight loss] at about 6–12 months, and sometimes a creep-up after 1 year. Even though [these adolescents] are significantly better, they're still not normal, so we should intervene even sooner,” Dr. Holly M. Ippisch said at the annual scientific sessions of the American Heart Association.
In a series of 87 adolescents who underwent Roux-en-Y bariatric surgery at Cincinnati Children's Hospital Medical Center, average body mass index dropped from 58 kg/m
Cardiovascular measures showed a similar pattern, with substantial improvements in parameters such as left ventricular mass and diastolic dysfunction during the first 6 months following surgery, followed by a leveling off to values that remained abnormally high and potentially dangerous.
“Even though it significantly improves [compared with baseline], it is still abnormal. It raises the issue of whether we should intervene [with bariatric surgery] sooner [in very obese adolescents], before they get beyond a certain point,” she said.
Diminishing weight loss more than 6 months out from surgery “is very interesting and is being seen at a number of U.S. centers” doing bariatric surgery on adolescents, commented Dr. Stephen R. Daniels, a pediatric cardiologist and professor and chairman of pediatrics at the University of Colorado in Denver.
“It's something that we don't understand and need to learn more about. From what we can tell they are in general eating in a healthy way. There probably is some plateauing in adults, too, but many of them get bariatric surgery at a healthier state [a lower body mass index] so they often get down to a body mass index that is closer to normal,” Dr. Daniels said in an interview.
At Cincinnati Children's and other centers, adolescents who are candidates for bariatric surgery must have a body mass index of at least 40 kg/m
When bariatric surgery for adolescents began a few years ago, “the thought was to be as conservative as possible, and reserve it for only the most severely affected adolescents,” he added.
“We didn't know if it was safe for adolescents, so it was reserved for extreme cases,” added Dr. Ippisch.
But the plateauing effect now being widely seen “is starting a thought process on what the criteria should be,” Dr. Daniels said.
The 87 adolescents who underwent Roux-en-Y surgery in Cincinnati were aged 13–19 years, and three-quarters were girls. Their average left ventricular mass at baseline was 52 g/m
Another way that Dr. Ippisch assessed left ventricular size and shape was to divide patients into four risk categories: normal (low risk), concentric remodeling (mildly elevated risk), eccentric ventricular hypertrophy (moderately elevated risk), and concentric ventricular hypertrophy (highest risk). The patients showed a shift from half having normal-shaped hearts at baseline to about 80% with normal shapes at 6, 12, and 24 months follow-up (see chart).
The patients also had an elevated left ventricular end diastolic pressure at baseline, an average mitral E/Ea ratio of about 7.0, indicating diastolic dysfunction, that improved to an average ratio of about 6.0 after 6 months and remained at that level through 2 years of follow-up.
Other improvements included heart rate, which fell from an average of 83 bpm at baseline to 63 bpm at 6 months and 61 bpm at 2 years, and blood pressure, which dropped from an average of 121/69 mm Hg at baseline to an average of 113/65 mm Hg at 6 months and 114/66 mm Hg at 2 years.
Dr. Ippisch had no commercial financial disclosures for this study.
The findings raise the issue of whether bariatric surgery should be performed sooner in very obese adolescents.
Source DR. IPPISCH
Source Elsevier Global Medical News