March 18, 2013

SAN FRANCISCO — New data show that a large proportion of obese patients undergoing laparoscopic gastric banding for weight loss had resolution of metabolic syndrome that was sustained for five years after the procedure. They also saw improvements in the individual components of the syndrome and a reduction in use of diabetes and antihypertensive medications.

Results from the small study were reported last week at the American College of Cardiology 2013 Scientific Sessions by Sean Heffron, MD, from New York University (NYU) School of Medicine, New York, and colleagues. The 50 patients included in the trial had a body mass index (BMI) of between 30 and 40 and at least 1 obesity-related comorbidity.

Heffron told Medscape Medical News that bariatric surgery has become an increasingly utilized procedure for obesity, with short-term trials suggesting improvements in cardiovascular risk factors, including lipid profiles. But these are some of the first data illustrating the durability of metabolic improvements with this type of operation, he noted.

Whether that will translate into prevention of outcomes down the road, we can't say with these data. Dr. Sean Heffron

"Nearly half of the patients met metabolic-syndrome criteria at baseline, and those resolved in all but a handful at year 1 and continued and persisted throughout year 5," he said. "Whether that will translate into prevention of outcomes down the road, we can't say with these data, but it does seem that the procedure resolves metabolic syndrome in those who have it at baseline, and it prevents the appearance of it in those who don't have it at baseline."

Gastric Banding Is a Reversible Bariatric Procedure

Gastric banding is a laparoscopic weight-loss procedure that involves placement of an inflatable silicon band or ring around the proximal portion of the stomach, with a subcutaneous port that allows for injection and adjustment of the band size, enabling regulation of the amount of food a patient is able to take in. In the first year of follow-up, patients come in for monthly appointments for band adjustment to tailor their weight loss, Dr. Heffron explained.

"It's reversible and doesn't affect baseline anatomy. Most patients leave the band in, but it can be removed if necessary, if there is a complication," he noted.

He and his colleagues reported on 50 patients who underwent gastric banding at their center at NYU, who were aged 18 to 60 years and had a history of obesity lasting 5 or more years. Average BMI was 35.1, and each patient had at least 1 obesity-related comorbidity; they were, however, less severely obese than many of the patients studied in recent trials of bariatric surgery, Dr. Heffron observed. The majority of data on this procedure are in patients with BMI of 40 or greater with severe comorbidities, he noted.

He also observed that the "metabolic abnormalities were not that great" in this study population, with average glycated hemoglobin (HbA1c) levels of 5.7%, "within the normal range." Despite this, almost half of the patients had metabolic syndrome at baseline.

The participants were followed annually for 5 years, with 47 patients available for follow-up at this time point: at these visits they underwent a physical exam and blood sampling. The primary outcome was diagnosis of metabolic syndrome, with secondary end points including the individual components of the metabolic syndrome and proportion of subjects using oral hyperglycemic or oral antihypertensive agents.

Improvements Sustained Out to 5 Years

At baseline, 43% of subjects met National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria for metabolic syndrome; this was reduced to 15% at year 1 and remained decreased throughout 5 years of follow-up (p<0.001).

BMI was significantly reduced at 5 years (to a mean of 27.9; P = .003), as was weight loss and waist circumference (P < .001). There was significant improvement in total cholesterol, LDL cholesterol, triglycerides, and HDL cholesterol at years 1 and 2 (P < .001), but only increase in HDL cholesterol was sustained out to 5 years (mean 56.9 mg/dL at baseline vs 70.29 mg/dL at 5 years). Fasting blood glucose was also significantly reduced and sustained out to 5 years.

The number of patients overall taking medication for diabetes and high blood pressure was small, Dr. Heffron said, but reductions were seen. At baseline, 7 participants were taking oral antidiabetic agents; at year 5, this was reduced to 4. One patient was on insulin and remained on insulin throughout. There were 9 patients taking antihypertensives at the start of the study, and 6 were still taking them by study end.

"Laparoscopic gastric banding produces significant weight loss and resolution of metabolic syndrome by improvement in multiple diagnostic criteria and reduces use of hyperglycemic and antihypertensive agents. These changes persist over 5 years following surgery," the researchers conclude.

Bypass Best for Sickest Obese Patients, but More Invasive

Dr. Heffron said recent 2-year data from the STAMPEDE study, which showed that bariatric surgery could put diabetes into remission, included much sicker patients, with an average HbA1c of 9.2%, although their mean BMI was similar.

In STAMPEDE, 2 bariatric procedures were examined, and the more invasive Roux-en-Y gastric bypass (RYGB) came out as being a markedly better option for these patients than sleeve gastrectomy. Gastric banding is much more akin to sleeve gastrectomy, Dr. Heffron noted.

Dr. Heffron has disclosed no relevant financial relationships. The study was sponsored by Allergan Health.

American College of Cardiology 2013 Scientific Sessions. Presented March 9, 2013. Abstract 1102-14