Clinical considerations for the management of residual diabetes following bariatric surgery

Long-term diabetes outcomes after bariatric surgery-managing medication withdrawl

BACKGROUND/OBJECTIVES

Bariatric surgery leads to type 2 diabetes mellitus (T2DM) remission, but recurrence can ensue afterwards. However, literature provides heterogenous remission/recurrence criteria and there is no consensus on long-term T2DM management after surgery. We aim to assess T2DM remission/recurrence rates using standardized criteria and to identify relapse predictors. We also intend to analyze the management of residual T2DM and the impact of maintaining/withdrawing metformin in avoiding future relapse.

SUBJECTS/METHODS

We investigated a cohort of 110 obese patients with T2DM who underwent bariatric surgery and were followed for 5 years (Y0-Y5). Patients who ever attained remission were accounted for cumulate remission, while prevalent remission was considered for individuals who were on remission in a specific visit.

RESULTS

A complete prevalent remission of 47.3% was reached at Y1 and it remained stable till Y5 (46.4-48.2%). Complete cumulative rate was of 57.3% at Y5. Five-year T2DM recurrence rate was 15.9% and it was associated with higher pre-operative HbA1c levels (β = 1.06; p < 0.05) and a milder excess body weight loss (EBWL) (β = 0.49; p < 0.05). Glucose-lowering agents were fully stopped in 51.4% of the patients till Y1 and in 16.2% of them afterwards. Medication withdrawal was mainly attempted in patients with a lower baseline HbA1c (β = 0.54; p < 0.01) and higher first-year EBWL (β = 1.04; p < 0.01). Patients that kept metformin after reaching a HbA1c in the complete remission range (<6.0%) did not have greater odds of avoiding relapse in the next visit (OR = 0.33; p = 0.08).

CONCLUSIONS

Baseline HbA1c and EBWL were the main variables driving both T2DM relapse after bariatric surgery and the attempt to withdrawal anti-diabetic medication. In our population keeping metformin once an HbA1c < 6.0% is achieved did not seem to diminish relapse but further studies on this matter are needed.

Effects of sleeve gastrectomy with jejuno-jejunal or jejuno-ileal loop on glycolipid metabolism in diabetic rats

AIM

To explore the effect of sleeve gastrectomy (SG) with jejuno-jejunal or jejuno-ileal loop on glycolipid metabolism in diabetic rats.

METHODS

Diabetic rats, which were induced by high-fat diet (HFD), nicotinamide and low-dose streptozotocin, underwent sham operations, SG, SG with jejuno-ileal loop (SG-JI) and SG with jejuno-jejunal loop (SG-JJ) followed by postoperative HFD. Then, at the time points of baseline and 2, 12 and 24 wk postoperatively, we determined and compared several variables, including the area under the curve for the results of oral glucose tolerance test (AUC_OGTT), serum levels of triglyceride, cholesterol and ghrelin in fasting state, homeostasis model assessment of insulin resistance (HOMA-IR), body weight, calorie intake, glucagon-like peptide (GLP)-1 and insulin secretions after glucose gavage at dose of 1 g/kg.

RESULTS

At 2 wk postoperatively, rats that underwent SG, SG-JJ and SG-JI, compared with sham-operated (SHAM) rats, demonstrated lower body weight, calorie intake and ghrelin (P < 0.05 vs SHAM), enhanced secretion of insulin and GLP-1 after glucose gavage (P < 0.05 vs SHAM), improved AUC_OGTT, HOMA-IR, fasting serum triglyceride and cholesterol (AUC_OGTT: 1616.9 ± 83.2, 837.4 ± 83.7, 874.9 ± 97.2 and 812.6 ± 81.9, P < 0.05 vs SHAM; HOMA-IR: 4.31 ± 0.54, 2.94 ± 0.22, 3.17 ± 0.37 and 3.41 ± 0.22, P < 0.05 vs SHAM; Triglyceride: 2.35 ± 0.17, 1.87 ± 0.23, 1.98 ± 0.30 and 2.04 ± 0.21 mmol/L, P < 0.05 vs SHAM; Cholesterol: 1.84 ± 0.21, 1.53 ± 0.20, 1.52 ± 0.20 and 1.46 ± 0.23 mmol/L). At 12 wk postoperatively, rats receiving SG-JJ and SG-JI had lower body weight, reduced levels of triglyceride and cholesterol and elevated level of GLP-1 compared to those receiving SG (P < 0.05 vs SG). At 24 wk after surgery, compared with SG, the advantage of SG-JJ and SG-JI for glucolipid metabolism was still evident (P < 0.05 vs SG). SG-JI had a better performance in lipid metabolism and GLP-1 secretion of rats than did SG-JJ.

CONCLUSION

SG combined with intestinal loop induces better glycolipid metabolism than simple SG, with the lipid metabolism being more improved with SG-JI compared to SG-JJ.

Alterations in gut microbiota during remission and recurrence of diabetes after duodenal-jejunal bypass in rats

AIM: To observe the alterations in gut microbiota in high-fat diet (HFD)-induced diabetes recurrence after duodenal-jejunal bypass (DJB) in rats.

METHODS: We assigned HDF- and low-dose streptozotocin-induced diabetic rats into two major groups to receive DJB and sham operation respectively. When the DJB was completed, we used HFD to induce diabetes recurrence. Then, we grouped the DJB-operated rats by blood glucose level into the DJB-remission (DJB-RM) group and the DJB-recurrence (DJB-RC) group. At a sequence of time points after operations, we compared calorie content in the food intake (calorie intake), oral glucose tolerance test, homeostasis model assessment of insulin resistance (HOMA-IR), concentrations of glucagon-like peptide 1 (GLP-1), serum insulin, total bile acids (TBAs) and lipopolysaccharide (LPS) and alterations in colonic microbiota.

RESULTS: The relative abundance of Firmicutes in the control (58.06% ± 11.12%; P < 0.05 vs sham; P < 0.05 vs DJB-RC) and DJB-RM (55.58% ± 6.16%; P < 0.05 vs sham; P < 0.05 vs DJB-RC) groups was higher than that in the sham (29.04% ± 1.36%) and DJB-RC (27.44% ± 2.17%) groups; but the relative abundance of Bacteroidetes was lower (control group: 33.46% ± 10.52%, P < 0.05 vs sham 46.88% ± 2.34%, P < 0.05 vs DJB-RC 47.41% ± 5.67%. DJB-RM group: 34.63% ± 3.37%, P < 0.05 vs sham; P < 0.05 vs DJB-RC). Escherichia coli was higher in the sham (15.72% ± 1.67%, P < 0.05 vs control, P < 0.05 vs DJB-RM) and DJB-RC (16.42% ± 3.00%; P < 0.05 vs control; P < 0.05 vs DJB-RM) groups than in the control (3.58% ± 3.67%) and DJB-RM (4.15% ± 2.76%) groups. Improved HOMA-IR (2.82 ± 0.73, P < 0.05 vs DJB-RC 4.23 ± 0.72), increased TBAs (27803.17 ± 4673.42 ng/mL; P < 0.05 vs DJB-RC 18744.00 ± 3047.26 ng/mL) and decreased LPS (0.12 ± 0.04 ng/mL, P < 0.05 vs DJB-RC 0.19 ± 0.03 ng/mL) were observed the in DJB-RM group; however, these improvements were reversed in the DJB-RC group, with the exception of GLP-1 (DJB-RM vs DJB-RC P > 0.05).

CONCLUSION: Alterations in gut microbiota may be responsible for the diabetes remission and recurrence after DJB, possibly by influencing serum LPS and TBAs.

Bariatric surgery and diabetes remission: how far have we progressed?

Obesity and type 2 diabetes mellitus have been associated with higher morbidity and mortality. Bariatric surgery results in substantial and sustained weight loss in morbidly obese patients and improves obstructive sleep apnea. Furthermore, bariatric surgery improves diabetes control, hypertension, quality of life, stroke, myocardial infarction and reduces mortality. Interestingly, bariatric surgery induces high rates of short and long-term diabetes remission. While the exact mechanisms behind this are not completely understood, improved insulin action, β-cell function and a complex interplay of hormones in the entero-insular axis appear to play major roles. Insulin action improves proportionally to weight loss and it gets completely normalized especially after bilio-pancreatic diversion. β-Cell function also seems to improve after a variety of bariatric surgeries. Seemingly, baseline β-cell function is able to predict future diabetes remission. This article will review the effectiveness of bariatric procedures on the remission and improvement of diabetes and its implicated mechanisms.

Remission of type 2 diabetes mellitus should not be the foremost goal after bariatric surgery

BACKGROUND

Remission of type 2 diabetes (T2D) is a desired outcome after bariatric surgery (BS). Even if this goal is not achieved, individuals who do not strictly fulfill remission criteria experience an overall improvement. The aim of this study was to evaluate the metabolic control status in patients considered as diabetes "non-remitters."

METHODS

A retrospective study of 125 patients (59.2 % women) with preoperative diagnosis of T2D who underwent BS in a single center (2006-2011) was conducted. We collected anthropometric and metabolic parameters before surgery and at 1-year follow-up. T2D remission was defined according to the 2009 consensus statement: glycosylated hemoglobin (HbA1c) <6 %, fasting glucose (FG) <100 mg/dLs, and absence of pharmacologic treatment. We evaluated metabolic status of non-remitters, according to the American Diabetes Association's (ADA) target recommendations: HbA1c <7 %, LDL-c <100 mg/dL, triglycerides <150 mg/dL, and HDL-c >40 (male) or >50 mg/dL (female).

STATISTICS

analysis of variance.

RESULTS

Baseline characteristics (mean ± SD): age 53.5 ± 9.7 years, BMI 43.5 ± 5.6 kg/m(2), time since diagnosis of T2D 7.7 ± 7.9 years, FG 162.0 ± 56.3 mg/dL, HbA1c 7.7 ± 1.6 %. ADA's target recommendations were present in 12 patients (9.6 %) preoperatively, and in 45 (36.0 %) at 1-year follow-up (p <0.001). Sixty-two (49.6 %) patients did not achieve diabetes remission; 26 (41.9 %) had now diet treatment, 30 (48.4 %) oral medications, and 6 (9.7 %) required insulin. Of the non-remitters, 57 (91.9 %) had HbA1c <7 % and 18 (40.0 %) achieved ADA's target recommendations. There were no differences between remitters and non-remitters in the number of individuals reaching ADA's combined metabolic control.

CONCLUSIONS

Although almost 50 % of the patients may not be classified as diabetes remitters, their significant improvement in metabolic control should be regarded as a success, according to most scientific societies' target recommendations.

Which criteria should be used to define type 2 diabetes remission after bariatric surgery?

Background

Comparison of diabetes remission rates after bariatric surgery using two different models of criteria.

Methods

Retrospective analysis of data from 110 patients with type 2 diabetes and morbid obesity who underwent bariatric surgery, preoperatively and at 18-month follow-up. Comparison of two models of remission: 1) 2009 consensus statement criteria; 2) simple criteria using ADA’s HbA1c diabetes diagnostic cut-off values.

Results

Patients’ mean ± SD preoperative characteristics were: age 53.3 ± 9.5 years, BMI 43.6 ± 5.5 kg/m², HbA1c 7.9 ± 1.8%, duration of diabetes 7.6 ± 7.5 years. 44.5% of patients with previous insulin therapy. With 2009 consensus statement criteria: complete, partial and no remission in 50%, 12.7% and 37.3%, respectively; with HbA1c criteria: 50%, 15% and 34.5% in the analogous categories (p = 0.673).

Conclusions

We suggest a simpler approach to evaluate diabetes remission after bariatric surgery, following the rationale of the definition of diabetes itself.