Gastric bypass results in greater loss of lean muscle mass….
Obese patients who undergo bariatric bypass surgery lose more lean muscle mass early in recovery compared with gastric banding patients, but an intense exercise program can mitigate the muscle loss, researchers found.
According to Ted Okerson, MD, from the University of California at Irvine, and Helmuth Billy, MD, from Ventura Advance Surgical Associates in Los Angeles, at 1 year post operation, the bypass surgery patients lost a mean of 19.62 lbs. of lean body mass compared with 12.41 lbs. in the laparoscopic adjustable gastric banding group.
Okerson told attendees here at the American Association of Clinical Endocrinologists meeting that, “The greatest reduction in lean body mass occurred within the first 3 months after the procedure (10.15% versus 4.95%).” However, on a per-pound basis, the loss of lean body mass was the same for both groups, which Okerson attributed to an intense resistance training and protein supplement program. “For each group, 21% of their weight loss was lean body mass.” “Despite a loss of fat and lean body mass in both groups at 1 year, the bypass patients lost 52% of their lean body mass in the first 3 months,” he emphasized. It may prove clinically meaningful in the long run in determining whether patients can sustain their weight loss, he said.
But the important factor, he said, is that it is possible to stanch the loss of lean body mass with resistance training and high protein intake. “Bypass patients can essentially lose the same amount of lean body mass as those who undergo gastric banding, but they have to really work at it.” “It’s an intense exercise program.”
Besides the addition of resistance training to aerobic exercise, patients supplemented their diet with 80 to 90 g of protein per day, which is more than the recommended 15 to 70 g per day, he said.
The researchers are continuing to follow these patients to see if they are able to maintain the protein, exercise, and vitamin supplementation over the longer term, and whether it results in sustained weight loss.
“Clinicians need to determine which procedure is best for their patients based upon these lifestyle changes.”
He said that gastric banding patients have to eat slower and wait between bites, while bypass patients tend to eat less because they feel full quickly. Also, if Roux-en-Y bypass surgery patients overeat or eat the wrong foods, they can have nausea, vomiting, or rapid stomach emptying.
For the study, researchers retrospectively examined records from a surgical database of patients who underwent gastric bypass or gastric banding from 2007 to 2009. Of the 480 patients in the study (188 bypass, 292 banding), the baseline body mass index (BMI) and percentage of body fat were not significantly different. There also were no differences in lean body mass, percentage of lean body mass, or basal metabolic rate.
At 1 year after the procedure, the bypass patients had a greater reduction in BMI (-17.10 versus -7.69 kg/m2) and excess weight loss compared with the gastric banding patients (78.35% versus 48.04%). But it came at the expense of greater loss of lean body mass early in recovery, Okerson reported.
Also at 1 year, bypass patients had a greater mean reduction in basal metabolic rate compared with those who had gastric banding (200.21 kcal/d versus 108.53 kcal/d).
“It’s up to the clinician to understand the data and help patients choose the procedure that best fits their lifestyle,” Okerson said. “The bottom line is we want them to be successful with their weight loss and, hopefully, with remission of comorbidities.”
- Patients undergoing bariatric gastric bypass had greater loss of lean body mass and greater decrease in basal metabolic rate at 1 year after the procedure than those who had gastric banding.
- Note that weight loss was greater in the gastric bypass group, and that an intensive aerobic and resistance exercise program helped these patients retain more lean body mass.
- This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Presented at the American Association of Clinical Endocrinologist (AACE) May 2012 Okerson T, et al “Changes in body composition following gastric bypass or gastric banding” Abstract 1315.