Does the RYGB common limb length influence hypertension remission and cardiometabolic risk factors? Data from the GATEWAY trial

Gut peptides before and following Roux-En-Y gastric bypass: A systematic review and meta-analysis

A systematic search was conducted in Medline Ovid, Embase, Scopus, and Cochrane Central Register of Controlled Trials up until March 2021 following PRISMA guidelines. Studies included evaluated ghrelin, GLP-1, PYY or appetite sensation via visual analogue scales (VASs) before and after Roux-en-Y gastric bypass (RYGB) in adults. A multilevel model with random effects for study and follow-up time points nested in study was fit to the data. The model included kcal consumption as a covariate and time points as moderators. Among the 2559 articles identified, k = 47 were included, among which k = 19 evaluated ghrelin, k = 40 GLP-1, k = 22 PYY, and k = 8 appetite sensation. Our results indicate that fasting ghrelin levels are decreased 2 weeks post-RYGB (p = 0.005) but do not differ from baseline from 6 weeks to 1-year post-RYGB. Postprandial ghrelin and fasting GLP-1 levels were not different from pre-surgical values. Postprandial levels of GLP-1 increased significantly from 1 week (p < 0.001) to 2 years post-RYGB (p < 0.01) compared with pre-RYGB. Fasting PYY increased at 6 months (p = 0.034) and 1 year (p = 0.029) post-surgery; also, postprandial levels increased up to 1 year (p < 0.01). Insufficient data on appetite sensation were available to be meta-analyzed.

Optimal Small Bowel Limb Lengths of Roux-en-Y Gastric Bypass

PURPOSE OF REVIEW

Gastric bypass and biliopancreatic diversion (BPD) have come full circle, from a loop configuration to a Roux-en-Y and finally back to a loop configuration as one anastomosis gastric bypass and single-anastomosis duodenal switch. Most surgeons performing Roux-en-Y gastric bypass (RYGB) do not measure the common channel (CC) length and most surgeons performing BPD do not measure the biliopancreatic limb length (BPL).

RECENT FINDINGS

The small bowel length in humans is variable from as short as < 400 cm to as long as > 1000 cm. The combination of these two facts means that even if surgeons keep the limb lengths constant, surgeons will get variable limb length due to the variability of small bowel length in patients. Hence, outcomes of weight loss, resolution of medical problems, or developing nutritional deficiencies which are related to limb length are variable. In this article, we evaluate the published literature related to the effect of varying the Roux limb, BPL, CC, and total alimentary limb lengths on the outcomes of RYGB. We have focused on historical and current randomized controlled trials as well as systematic reviews and meta-analysis to outline the current literature and our interpretation of this literature.

Shorter History of Hypertension as a Predictor of Hypertension Remission after 3-years of Bariatric Surgery: Data from the GATEWAY Trial

BACKGROUND

Previous evidence explored predictors of hypertension (HTN) remission after bariatric but data are limited to observational studies and lack of ambulatory blood pressure monitoring (ABPM). This study was aimed to evaluate the rate of HTN remission after bariatric surgery using ABPM and to define predictors of mid-term HTN remission.

METHODS

We included patients enrolled in the surgical arm of the GATEWAY randomized trial. HTN remission was defined as controlled blood pressure (< 130 × 80 mmHg) evaluated by 24-h ABPM while no need of anti-hypertensive medications after 36 months. A multivariable logistic regression model was used to assess the predictors of HTN remission after 36 months.

RESULTS

46 patients submitted Roux-en-Y gastric bypass (RYGB). HTN remission occurred in 39% (n = 14 out of 36 patients with complete data at 36 months). Patients with HTN remission had shorter HTN history than no remission group (5.9 ± 5.5 vs. 12.5 ± 8.1 years; p = 0.01). The baseline insulin levels were lower in patients who presented HTN remission, although not statistically significant (OR: 0.90; CI 95%: 0.80-0.99; p = 0.07). In the multivariate analysis, the HTN history (years) was the only independent predictor of HTN remission (OR: 0.85; 95% CI: 0.70-0.97; p = 0.04). Therefore, for each additional year of HTN history, the chance of HTN remission decreases by approximately 15% after RYGB.

CONCLUSION

After 3 years of RYGB, HTN remission defined by ABPM was common and independently associated with a shorter HTN history. These data underscore the need of early effective approach of obesity aiming greater impact in its comorbidities.

Proximal Roux-en-Y gastric bypass: Addressing the myth of limb length

BACKGROUND

Some studies suggest that changes in weight or metabolic outcomes are affected by the lengths of the gastrointestinal limbs in the Roux-en-Y gastric bypass.

METHODS

Participants (N = 1,770) underwent primary Roux-en-Y gastric bypass and were followed ≤7 years in the Longitudinal Assessment of Bariatric Surgery-2, a multicenter US cohort study. Alimentary limb and biliopancreatic limb lengths were measured according to research protocol; common channel was measured in a subsample (N = 547). Aimentary limb, biliopancreatic limb, and common channel ratio to total small bowel length were calculated.

RESULTS

Median presurgery body mass index was 46 (25th-75th percentile: 43-51) kg/m2. Medians (25th-75th percentiles) for alimentary limb length were 125 cm (100-150), for biliopancreatic limb length were 50 cm (50-60), and common channel length were 410 cm (322-520). Statistics for ratios to the small bowel length were 0.23 (0.18-0.27) for alimentary limb, 0.09 (0.07-0.10) for biliopancreatic limb, and 0.69 (0.63-0.73) for common length. There were no significant associations between alimentary limb, biliopancreatic limb, common channel, alimentary limb ratio, biliopancreatic limb ratio or common channel ratio, and either weight loss or improvement in cardiometabolic outcomes.

CONCLUSION

The common channel length in Roux-en-Y gastric bypass is highly variable between individuals. None of the limb lengths in this study, nor alimentary limb, biliopancreatic limb, or common channel ratios, seem to be related to weight loss or metabolic improvements >7 years.