Background: Elevated hemoglobin A1c (HbA1c) values are known to increase the risk of diabetic retinopathy, nephropathy, and peripheral neuropathy. The current guidelines recommend maintaining HbA1c values at <7%. We assessed the effect of laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) on HbA1c values in diabetic patients compared with a conventionally treated cohort.
Methods: A retrospective review of a prospective bariatric database identified diabetic patients who had undergone LRYGB from 2001 to 2005. A cohort of conventionally treated obese (body mass index >35 kg/m(2)) diabetic patients was matched by age and gender. The inclusion criteria consisted of a preoperative/initial HbA1c and 2 postoperative/follow-up HbA1c values compiled from our institution's comprehensive electronic medical record system. The patients in the LRYGB cohort were also required to have had a 1-year postoperative weight recorded. Statistical analysis was performed using the Student t test.
Results: Each cohort consisted of 40 women (78.4%) and 11 men (21.6%). The mean age was 48.8 +/- 8.3 years for the surgical cohort and 48.2 +/- 8.3 years for the conventionally treated cohort. The mean body mass index was 47.7 +/- 5.7 kg/m(2) preoperatively for the surgical cohort and 45.1 +/- 5.7 kg/m2 initially for the conventionally treated cohort. The mean preoperative/initial HbA1c was 7.5% +/- 1.4% and 7.0% +/- 1.1% for the surgical and conventionally treated groups, respectively. At 1 year, HbA1c results were available for 46 LRYGB and 41 conventionally treated patients. The corresponding mean HbA1c values were 5.8% +/- 1.1% and 7.0% +/- .9% (P = .001). At 3 years, the mean HbA1c was 6.1% +/- 1.2% and 7.8% +/- 1.5% for 28 surgical and 36 conventionally treated patients, respectively (P = .001). The surgical patients' use of oral hypoglycemic medications and/or insulin decreased from 84.3% before surgery to 22.4% at 1 year postoperatively.
Conclusion: The patients who underwent LRYGB had a significant and sustained improvement in the HbA1c value compared with the conventionally treated obese patients with type 2 diabetes mellitus.