Clinical and Patient-Centered Outcomes in Obese Patients With Type 2 Diabetes 3 Years After Randomization to Roux-en-Y Gastric Bypass Surgery Versus Intensive Lifestyle Management: The SLIMM-T2D Study

Abstract

OBJECTIVE

To compare the effect of Roux-en-Y gastric bypass (RYGB) surgery versus intensive medical diabetes and weight management (IMWM) on clinical and patient-reported outcomes in obese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We prospectively randomized 38 obese patients with type 2 diabetes (15 male and 23 female, with mean ± SD weight 104 ± 16 kg, BMI 36.3 ± 3.4 kg/m ², age 52 ± 6 years, and HbA _1c 8.5 ± 1.3% [69 ± 14 mmol/mol]) to laparoscopic RYGB ( n = 19) or IMWM ( n = 19). Changes in weight, HbA _1c, cardiovascular risk factors (UKPDS risk engine), and self-reported health status (the 36-Item Short-Form [SF-36] survey, Impact of Weight on Quality of Life [IWQOL] instrument, and Problem Areas in Diabetes Survey [PAID]) were assessed.

RESULTS

After 3 years, the RYGB group had greater weight loss (mean −24.9 kg [95% CI −29.5, −20.4] vs. −5.2 [−10.3, −0.2]; P < 0.001) and lowering of HbA _1c (−1.79% [−2.38, −1.20] vs. −0.39% [−1.06, 0.28] [−19.6 mmol/mol {95% CI −26.0, −13.1} vs. −4.3 {−11.6, 3.1}]; P < 0.001) compared with the IMWM group. Changes in cardiometabolic risk for coronary heart disease and stroke were all more favorable in RYGB versus IMWM ( P < 0.05 to P < 0.01). IWQOL improved more after RYGB ( P < 0.001), primarily due to subscales of physical function, self-esteem, and work performance. SF-36 and PAID scores improved in both groups, with no difference between treatments. A structural equation model demonstrated that improvement in overall quality of life was more strongly associated with weight loss than with improved HbA _1c and was manifest by greater improvements in IWQOL than with either SF-36 or PAID.

CONCLUSIONS

Three years after randomization to RYGB versus IMWM, surgery produced greater weight loss, lower HbA _1c, reduced cardiovascular risk, and improvements in obesity-related quality of life in obese patients with type 2 diabetes.