Progression of diabetic retinopathy after bariatric surgery.

AIM: To assess the impact of bariatric surgery on the progression of diabetic retinopathy in patients with Type 2 diabetes. METHOD: We conducted a retrospective, observational study of patients with Type 2 diabetes who underwent bariatric surgery between 1 January 2001 and 31 December 2012 and had hospital-based retinal screening records. Data were collected from four surgical centres. Those who had pre-operative retinal screening and at least one post-operative retinal screen were eligible for analysis. A generalized linear mixed model was used to explore significant clinical predictors on the post-operative grade severity over time, controlling for important baseline characteristics. RESULTS: Three hundred and eighteen patients were eligible for analysis. Of these, 68.6% had no diabetic retinopathy pre-operatively compared with 18.9%, 8.5% and 4% with a diabetic retinopathy grade of minimal, mild or moderate and higher, respectively. First post-operative retinal screening results showed that after surgery 73% had no change in their diabetic retinopathy grade, 11% regressed and 16% progressed. The probability of having a diabetic retinopathy grade of moderate or higher over time post surgery was significantly associated with the magnitude of HbA1c reduction from pre-surgery HbA1c levels, a shorter post-operative retinal screening duration, more severe pre-operative retinal screening grade, male gender and non-Maori/Pacific ethnicity. CONCLUSIONS: A higher pre-operative diabetic retinopathy grade, and a large decrease in HbA1c post surgery warrant closer monitoring of diabetic retinopathy after bariatric surgery. Further prospective, randomized studies are required to investigate the gender and ethnic differences found.

Lower glycemic fluctuations early after bariatric surgery partially explained by caloric restriction.

BACKGROUND: We assessed the acute impact of laparoscopic Roux-en-Y gastric bypass (GBP) or sleeve gastrectomy (SG) compared to caloric-matched control group without surgery on glucose excursion in obese patients with type 2 diabetes, and examined if this was mediated by changes in insulin resistance, early insulin response or glucagon-like peptide (GLP)-1 levels. METHODS: Six-day subcutaneous continuous glucose monitoring (CGM) recordings were obtained from patients beginning 3 days before GBP (n = 11), SG (n = 10) or fasting in control group (n = 10). GLP-1, insulin and glucose were measured during 75 g oral glucose tolerance testing at the start and end of each CGM. RESULTS: Post-operative hyperglycaemia occurred after both surgeries in the first 6 h, with a more rapid decline in glycaemia after GBP (p < 0.001). Beyond 24 h post-operatively, continuous overlapping of net glycaemia action reduced from baseline after GBP (median [interquartile range]) 1.6 [1.2-2.4] to 1.0 [0.7-1.3] and after SG 1.4 [0.9-1.8] to 0.7 [0.7-1.0]; p < 0.05), similar to controls (2.2 [1.7-2.5] to 1.3 [0.8-2.8] p < 0.05). Higher log GLP-1 increment post-oral glucose occurred after GBP (mean ± SE, 0.80 ± 0.12 vs. 0.37 ± 0.09, p < 0.05), but not after SG or control intervention. Among subgroup with baseline hyperglycaemia, a reduction in HOMA-IR followed GBP. Reduction in time and level of peak glucose and 2-h glucose occurred after both surgeries but not in controls. CONCLUSIONS: GBP and SG have a similar acute impact on reducing glycaemia to caloric restriction; however, with a superior impact on glucose tolerance.