The Short-Term Renal Effects of Bariatric Surgery: A Comparative Study Between Sleeve Gastrectomy and One Anastomosis Gastric Bypass Operations Among Egyptian Patients With Severe Obesity

Effects of bariatric surgery on renal function: a retrospective cohort study comparing one-year outcomes between one-anastomosis gastric bypass and Roux-en-Y gastric bypass

BACKGROUND

Evidence on the effect of one-anastomosis gastric bypass (OAGB) on renal function is limited.

OBJECTIVE

To compare the evolution of estimated renal function observed 1 year after OAGB and Roux-en-Y gastric bypass (RYGB) in individuals with obesity.

DESIGN AND SETTING

Observational, analytical, and retrospective cohort study. Tertiary-level university hospital.

METHODS

This study used a prospectively collected database of individuals who consecutively underwent bariatric surgery. Renal function was assessed by calculating the estimated glomerular filtration rate (eGFR), according to the Chronic Kidney Disease Epidemiology Collaboration. The one-year variation in the eGFR was compared between the procedures.

RESULTS

No significant differences in age, sex, obesity-associated conditions, or body mass index were observed among individuals who underwent either OAGB or RYGB. OAGB led to a significantly higher percentage of total (P = 0.007) and excess weight loss (P = 0.026). Both OAGB and RYGB led to significantly higher values of eGFR (103.9 ± 22 versus 116.1 ± 13.3; P = 0.007, and 102.4 ± 19 versus 113.2 ± 13.3; P < 0.001, respectively). The one-year variation in eGFR was 11 ± 16.2% after OAGB and 16.7 ± 26.3% after RYGB (P = 0.3). Younger age and lower baseline eGFR were independently associated with greater postoperative improvement in renal function (P < 0.001).

CONCLUSION

Compared with RYGB, OAGB led to an equivalent improvement in renal function 1 year after the procedure, along with greater weight loss.

Dietary weight loss strategies for kidney stone patients

PURPOSE

Overweight has been associated with an increased risk of incident and recurrent kidney stone disease. Weight reduction is the therapeutic consequence to decrease the risk of stone formation. This review examines the effectiveness of different weight loss strategies on weight reduction and cardiometabolic risk profile, with a particular focus on risk factors for urolithiasis.

METHODS

A selective literature search was performed using PubMed and Cochrane library.

RESULTS

Clinical evidence for the potential benefits of dietary weight loss strategies for kidney stone disease is limited. A conventional, energy-restricted diet may significantly induce weight loss and reduce urinary supersaturation of calcium oxalate in overweight individuals with or without a history of stone formation. The current data indicate that an energy-restricted diet with partial meal replacement may additionally decrease the relative supersaturation of uric acid and further improve the cardiometabolic risk profile, and, thus, may be a favourable option for overweight kidney stone patients. Studies on the Mediterranean and DASH diets on the association between weight loss and the risk of urinary stone formation are lacking.

CONCLUSION

An energy-restricted diet with or without meal replacement could be a promising weight loss strategy for overweight kidney stone patients. Further studies are needed to evaluate the impact of different weight loss strategies on urinary risk factors and cardiometabolic risk profile in urolithiasis.

Effect of Two Different Dietary Weight Loss Strategies on Risk Factors for Urinary Stone Formation and Cardiometabolic Risk Profile in Overweight Women

Overweight has been suggested to increase the risk of kidney stone formation. Although weight reduction might affect risk factors for urolithiasis, findings on the impact of different dietary weight loss strategies are limited. This randomized, controlled study evaluated the effect of a conventional energy-restricted modified diet with (MR group) or without meal replacement (C group) on risk factors for stone formation in overweight women without a history of urolithiasis. Of 105 participants, 78 were included into the per-protocol analysis. Anthropometric, clinical, biochemical, and 24 h urinary parameters were collected at baseline and after 12 weeks. Although both dietary interventions resulted in a significant weight reduction, relative weight loss and rate of responders were higher in the MR group. Weight loss improved cardiometabolic risk profile in both groups. Unfortunately, the benefit of decreased GPT activity in the C group was offset by a significant increase in homocysteine and a decline in GFR. While the relative supersaturation of calcium oxalate decreased significantly in both groups, a significant decline in serum uric acid concentration and relative supersaturation of uric acid was observed only in the MR group. Finally, the energy-restricted modified diet with meal replacement showed significant advantages over the energy-restricted modified diet alone.

Renal Function Following Bariatric Surgery: a Literature Review of Potential Mechanisms

Obesity is a major and independent risk factor for onset and progression of many renal diseases. Bariatric surgery (BS) improves renal function by improving obesity-related metabolic disorders. However, the procedure is also accompanied by renal risks, including acute kidney injury (AKI) and oxalate nephropathy. Here, we briefly review the history and principle of frequently applied technique for BS and summarize the comprehensive BS effect on kidney function. Importantly, we highlight the possible molecular mechanisms associated with the recovery of renal function to provide novel ideas for future studies and clinical applications.

Comparative Effectiveness of Roux-en-Y Gastric Bypass vs. One Anastomosis Gastric Bypass on Kidney Function

PURPOSE

Obesity and its associated medical problems increase risk of kidney function decline while prior studies suggest that bariatric surgery may improve kidney outcomes. However, little is known about the comparative effectiveness of different types of bariatric surgery on kidney function. In this study, we compare the effects of laparoscopic one anastomosis gastric bypass (LOAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGB) on kidney function one year after surgery.

MATERIALS AND METHODS

The patients' demographic, medical, and surgical data were prospectively collected and retrospectively reviewed. Type 2 diabetes mellitus, hypertension, and dyslipidemia, body mass index (BMI), and kidney function tests were obtained before and one year after surgery. Kidney function was evaluated by estimated glomerular filtration rate (eGFR) and spot urine albumin to creatinine ratio (ACR). Changes in eGFR and ACR were compared between LRYGB vs. LOAGB after adjustment for confounders (age, sex, remission of associated medical problems, preoperative BMI, and percentage of excess BMI loss) using ANCOVA model.

RESULTS

Both surgical techniques significantly decreased the post-surgery presence of diabetes, hypertension, and dyslipidemia (p < 0.001 for all paired comparisons). The eGFR level significantly increased and the ACR level significantly decreased in both groups (p < 0.001 for all paired comparisons before and after adjustment). However, eGFR and ACR mean differences between LRYGB and LOAGB were not significantly different after adjustment for confounding variables (p = 0.9 and 0.4, respectively).

CONCLUSION

Both LOAGB and LRYGB improved 1-year eGFR and ACR equally independently from weight loss and other confounders.