Background: Roux-en-Y gastric bypass surgery (RYGBP) has been demonstrated to be safe and effective at achieving weight loss in the majority of severely obese patients. Despite this, a subset of patients fails to achieve expected weight loss outcomes. Factors associated with poor or suboptimal weight loss have not been well-defined.
Methods: All patients undergoing open RYGBP by a single surgeon using a standardized surgical technique and clinical pathway at a dedicated bariatric center between 1999 and 2004 were reviewed, and weight loss was assessed at 12-months follow-up. Suboptimal weight loss (SWL) was defined as a failure to lose at least 40 percent of excess body weight by one year post-operatively.
Results: Follow-up at 12-months was available in 495 (89%) of the 555 consecutive patients who underwent RYGBP over the 5-year period (87% white, 16% male, mean age 42 years, mean BMI (body mass index) 55 kg/m2). SWL occurred in 55 patients (11%) and was associated with increased BMI (p=0.0002), presence of diabetes mellitus (p=0.0002), Medicaid insurance status (p=0.04), and male gender (p=0.01) on univariate analysis. Age, race, and other pre-operative co-morbidities (coronary artery disease, hypertension, hypercholesterolemia, sleep apnea) did not correlate with SWL. While diabetes mellitus was associated with SWL, degree of treatment (insulin dependent, oral hypoglycemics, or diet controlled) was not. On multivariate analysis, increased BMI (p=0.003), diabetes mellitus (p=0.002), and male gender (p=0.04) remained significantly associated with SWL, but insurance status was not (p=0.11). Those with Medicaid compared to other forms of medical insurance tended to be younger (p=0.01) and have higher BMI (p=0.0002).
Conclusions: RYGBP remains an effective and safe procedure for achieving weight loss in the great majority of severely obese patients. Suboptimal weight loss appears to be associated with greater BMI, male gender, and diabetes. When these factors are accounted for, insurance status does not appear to be predictive of poor weight loss. These factors may help to identify patients who might benefit from increased perioperative education and counseling.