Diabetes limits weight loss after bariatric surgery

Individuals with diabetes may experience a lesser extent of weight loss after bariatric surgery than those without diabetes, according to a study.

For the study, researchers used data from the Michigan Bariatric Surgery Cohort (MI-BASiC) and performed repeated measures analysis to establish whether diabetes was a predictor of weight loss outcomes over 5 years after surgery.

MI-BASiC included 714 consecutive adult patients (mean age at the time of surgery 44.4 years, 79 percent women, mean body mass index [BMI] at baseline 48.6 kg/m²) who received gastric bypass (GB; n=380) or sleeve gastrectomy (SG; n=334) for obesity. Patients in the SG group had significantly greater weight and BMI (p<0.01 for both), while those in the GB group had significantly higher HbA_1c (p=0.03) and total cholesterol (p=0.04).

A total of 149 patients (39.2 percent) in the GB group and 108 patients (32.3 percent) in the SG group had diabetes. In the first year after surgery, patients who underwent GB lost 42.8 kg, and their BMI dropped by 15.2 kg/m². For patients who underwent SG, weight and BMI decreased by 34.3 kg and 12.2 kg/m², respectively. At year 5, HbA_1c decreased by 0.67 percent in the GB group and by 0.29 percent in the SG group from baseline.

Multivariable analysis showed that patients with diabetes in the GB and SG groups had a significantly lower percentage of total (p=0.0023) and excess weight loss (p=0.0212) compared with those who had no diabetes.