Outcomes in glycemic control in the intermediate follow-up of Roux-en-Y gastric bypass: a Brazilian cohort study

Background

It is not widely known whether glycemic control (GC) is sustained after Roux-en-Y gastric bypass (RYGB). The objective of this study was to investigate incidence and remission of type 2 diabetes mellitus (T2DM) among 284 individuals with body mass index (BMI)≥35 kg/m² at operation (1998–2011) through 2013.

Methods

Baseline GC was based on fasting glycemia (FG), hemoglobin A1c (HbA1c), and medication. Incident T2DM, complete (normal GC/HbA1c) and partial (abnormal FG/A1c) remission at the last follow-up visit, and relapse were the outcomes of interest. Kaplan-Meier curves and log-rank tests were used to compare time to improvement according to insulin use and HbA1c levels at baseline. Pre- and postoperative determinants of T2DM improvement were investigated by logistic regression.

Results

Participants were predominantly female (220; 77.2%) with mean age of 39.6 (10.5) years and median BMI of 51.9 (46.1–57.5) kg/m² at operation. The mean follow-up time was 5.1 (3.2) years with 67.5% (55.0–78.4) of excess BMI loss (EBL) at the 5^th year. Normal GC, abnormal FG, and T2DM were observed in 169 (59.5%), 32 (11.2%), and 83 (29.3%) participants at baseline, respectively. The 7 (4.1%) patients with incident T2DM had lower BMI at baseline than those who remained with normal GC (43.6 kg/m² [42.0–50.8] versus 52.1 kg/m² [46.7–57.7]; P = .01). Complete and partial T2DM remission occurred in 61 (61.3%) and 5 (6.7%) participants, respectively. Baseline HbA1c was associated with a significant difference in the proportion of cases with remission at the 5^th year of follow-up (P = .016). Age (OR .83; 95% CI .72–.95) and % EBL at the 2^nd year of follow-up (OR 1.05; 95% CI 1.01–1.09) were independent determinants of T2DM improvement. Relapse occurred in 14 (14.3%) cases.

Conclusion

We observed a low incidence and impressive improvement rates of T2DM after intermediate follow-up of RYGB.