Effect of laparoscopic Roux-en-Y gastric bypass surgery on hemoglobin A1c levels in diabetic patients: a matched-cohort analysis

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 < 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/m(2) 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. 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. (Surg Obes Relat Dis 2009;5:4-10.) (C) 2009 American Society for Metabolic and Bariatric Surgery. All rights reserved.