MONDAY, Oct. 22, 2018 (HealthDay News) -- Measuring the percentage of weight regained following the maximum amount of weight lost after Roux-en-Y gastric bypass (RYGB) surgery best predicts a patient's risk for several serious health problems, according to a study published in the Oct. 16 issue of the Journal of the American Medical Association.
Wendy C. King, Ph.D., from the University of Pittsburgh, and colleagues used data from 1,406 adults who underwent bariatric surgery at 10 hospitals in six U.S. cities (March 2006 through April 2009; median pre-surgery body mass index [BMI], 46.3 kg/m²) to estimate weight regain after reaching nadir weight following RYGB surgery. Assessments using various measures of weight regain were conducted within 30 days before surgery, at six months after surgery, and then annually until January 2015, with all included patients being followed for at least five years.
The researchers found that the median percentage of maximum weight loss was 37.4 percent of pre-surgery weight, and this loss occurred a median of 2.0 years after surgery. While weight regain continued to increase throughout follow-up, the rate of weight regain was highest during the first year after reaching nadir weight. The percentage of maximum weight lost had the strongest association and best model fit for all outcomes except hyperlipidemia, which had a slightly stronger association with BMI compared with other continuous weight gain measures. For dichotomous measures, ≥20 percent of maximum weight lost performed best for most of the outcomes and was the second best measure for hyperlipidemia (following ≥10 kg of weight) and hypertension (following ≥10 percent of maximum weight lost).
"Our study can help providers identify the best way to calculate weight regain after bariatric surgery to identify more specifically the patients at risk for recurrence or new onset of health problems," a coauthor said in a statement.