The Impact of Early-Stage Chronic Kidney Disease on Weight Loss Outcomes After Gastric Bypass.

PURPOSE: Weight loss achieved through bariatric metabolic surgery was demonstrated to be effective at reversing chronic kidney dysfunction associated with obesity-related glomerulopathy. However, robust data on how pre-operative kidney status impacts on bariatric metabolic surgery weight loss outcomes is still lacking. The aim of this study was to evaluate the impact of kidney dysfunction on weight loss outcomes after bariatric metabolic surgery. METHODS: Patients with obesity to be submitted to gastric bypass surgery underwent a pre-operative evaluation of creatinine clearance, estimated glomerular filtration rate (eGFR), proteinuria, and albuminuria in 24-hour urine. Body mass index (BMI), % total weight loss (%TWL), and % excess BMI loss (%EBMIL) were assessed at 6 and 12 months after surgery. RESULTS: Before surgery, patients (N=127) had a mean BMI of 39.6 ± 3.0 kg/m2, and 56.7% (n=72) had a creatinine clearance > 130 mL/min, 23.6% (n= 30) presented proteinuria > 150 mg/24h, and 15.0% (n= 19) presented albuminuria > 30 mg/24h. After surgery, the mean BMI was 27.7 kg/m2 and 25.0 kg/m2 at 6 and 12 months, respectively (p<0.0001). The %TWL was lower in patients with pre-operative eGFR < percentile 25 (34.4 ± 5.8% vs 39.4 ± 4.9%, p=0.0007, at 12 months). There were no significant correlations between weight loss metrics and pre-operative creatinine clearance rate, proteinuria, or albuminuria. CONCLUSION: Early-stage chronic kidney disease (G2) has a negative impact on short-term weight loss outcomes after bariatric metabolic surgery, albeit in a magnitude inferior to the clinically relevant threshold.

Renal Dysfunction Phenotypes in Patients Undergoing Obesity Surgery.

Obesity surgery candidates are at an increased risk of kidney injury, but pre-operative evaluation usually neglects kidney function assessment. This study aimed to identify renal dysfunction in candidates for bariatric surgery. To reduce the sources of bias, subjects with diabetes, prediabetes under metformin treatment, neoplastic or inflammatory diseases were excluded. Patients' (n = 192) average body mass index was 41.7 ± 5.4 kg/m2. Among these, 51% (n = 94) had creatinine clearance over 140 mL/min, 22.4% (n = 43) had proteinuria over 150 mg/day and 14.6% (n = 28) albuminuria over 30 mg/day. A creatinine clearance higher than 140 mL/min was associated with higher levels of proteinuria and albuminuria. Univariate analysis identified sex, glycated hemoglobin, uric acid, HDL and VLDL cholesterol as being associated with albuminuria, but not with proteinuria. On multivariate analysis, glycated hemoglobin and creatinine clearance as continuous variables were significantly associated with albuminuria. In summary, in our patient population prediabetes, lipid abnormalities and hyperuricemia were associated with albuminuria, but not with proteinuria, suggesting different disease mechanisms might be implicated. Data suggest that in obesity-associated kidney disease, tubulointerstitial injury precedes glomerulopathy. A significant proportion of obesity surgery candidates present clinically relevant albuminuria and proteinuria along with renal hyperfiltration, suggesting that routine pre-operative assessment of these parameters should be considered.

CT volumetry performs better than nuclear renography in predicting estimated renal function one year after living donation.

The evaluation of split renal function (SRF) is a critical issue in living kidney donations and can be evaluated using nuclear renography (NR) or computerized tomography (CT), with unclear comparative advantages. We conducted this retrospective study in 193 donors to examine the correlation of SRF assessed by NR and CT volumetry and compared their ability to predict remaining donor renal function at 1 year, through multiple approaches. A weak correlation between imaging techniques for evaluating the percentage of the remaining kidney volume was found in the global cohort, with an R2 = 0.15. However, the Bland-Altman plot showed an acceptable agreement (95% of the difference between techniques falling within - 8.51 to 6.11%). The predicted and observed eGFR one year after donation were calculated using the CKD-EPI, and CG/BSA equations. CT volume showed a better correlation than NR for both formulas (adjusted R2 of 0.42. and 0.61 vs 0.37 and 0.61 for CKD-EPI and CG/ BSA equations, respectively). In non-nested modeling tests, CT volumetry was significantly superior to NR for both equations. CT volumetry performed better than NR in predicting the estimated renal function of living donors at 1-year, independently from the eGFR equation.

Why Donors Do Not Donate: A Living Donation Program Experience.

BACKGROUND: A living donor (LD) kidney transplant is the best therapeutic option for end-stage kidney disease. Potential donors must undergo multiple analyses and the rates of live donation can be as low as 8% to 18%. Here, we report on the live kidney donor program in our unit with emphasis on the reasons why potential donors do not proceed to donation. METHODS: We performed a single-center retrospective study of all potential kidney donors with a first LD appointment at Centro Hospitalar Universitário do Porto between January 2016 and December 2020. RESULTS: In our cohort there were 395 potential donors. From the potential donors who finished assessment, 131 were approved for donation and 239 dropped out. After assessment, 104 (28.1%) recipients received a living kidney transplant, 24 of which received a living kidney transplant through the kidney paired exchange program. The individuals who did not proceed to the surgery (n = 239) had a median age of 46.5 years, 64.4% were female, and 34 pairs were ABO-incompatible. The most frequent donor-recipient relationships were spouses, siblings and parents. The 2 most important causes of dropout were due to medical, surgical or psychological contraindications and the donor's voluntary withdrawal. When we evaluated the variables most related to dropout, they were not because of being a spouse and ABO incompatibility. CONCLUSIONS: When compared to other studies, we showed a relatively higher rate of successful live donations, possibly aided by the presence of cross-over transplantation. Targeted education and support at an earlier stage of the donor assessment process may lead to a better engagement and lower probability of early dropout.

Metabolomics as a tool for the early diagnosis and prognosis of diabetic kidney disease.

Diabetic kidney disease (DKD) is one of the most prevalent comorbidities of diabetes mellitus and the leading cause of the end-stage renal disease (ESRD). DKD results from chronic exposure to hyperglycemia, leading to progressive alterations in kidney structure and function. The early development of DKD is clinically silent and when albuminuria is detected the lesions are often at advanced stages, leading to rapid kidney function decline towards ESRD. DKD progression can be arrested or substantially delayed if detected and addressed at early stages. A major limitation of current methods is the absence of albuminuria in non-albuminuric phenotypes of diabetic nephropathy, which becomes increasingly prevalent and lacks focused therapy. Metabolomics is an ever-evolving omics technology that enables the study of metabolites, downstream products of every biochemical event that occurs in an organism. Metabolomics disclosures complex metabolic networks and provide knowledge of the very foundation of several physiological or pathophysiological processes, ultimately leading to the identification of diseases' unique metabolic signatures. In this sense, metabolomics is a promising tool not only for the diagnosis but also for the identification of pre-disease states which would confer a rapid and personalized clinical practice. Herein, the use of metabolomics as a tool to identify the DKD metabolic signature of tubule interstitial lesions to diagnose or predict the time-course of DKD will be discussed. In addition, the proficiency and limitations of the currently available high-throughput metabolomic techniques will be discussed.

Diabetic and Elder Patients Experience Superior Cardiovascular Benefits After Gastric Bypass Induced Weight Loss.

Background/Objetives: Obesity and obesity related co-morbidities are well-recognized risks for cardiovascular (CV) disease and mortality. Weight loss improves CV risk factors and the efficacy of bariatric surgery in decreasing CV mortality is now well-established. Our aim was to assess CV risk progression and occurrence of CV events in a cohort of patients that underwent Roux-en-Y gastric bypass (RYGB) for obesity treatment in a single academic public center. Subjects and Methods: Ten year CV risk was estimated using the Framingham Equation at baseline and 2 years after RYGB surgery in our patients cohort (n = 260). In the subgroup with a follow-up time longer than 4 years after surgery (n = 185; mean 5.4 ± 0.1 years), CV risk adjusted for the time length after RYGB was similarly estimated and the occurrence of CV events for outcome adjudication was monitored during the same time period by reviewing the hospital patients' record, the electronic national health system patient register and our center outpatient clinic records. Results: Ten year CV risk was significantly reduced 2 years after surgery when compared to baseline, with reductions of 1.65 ± 0.25% in the risk of CV disease. Patients with prior type 2 diabetes and aged 50 years or older experienced a significantly superior CV risk reduction, with diabetic patients experiencing a reduction of their 10-year CV disease risk of 3.58 ± 1.11% vs. a reduction of 1.31 ± 0.20% in non-diabetic patients and with the 10-year risk of CV disease dropping 3.41 ± 0.75% in patients older than 50 vs. a reduction of 0.99 ± 0.18 in patients up to 50 years. For the subgroup of patients with a longer follow-up time, baseline CV risk estimation predicted the occurrence of 6.08 ± 0.56 cardiovascular disease (CVD) events, 3.87 ± 0.39 coronary heart disease (CHD) events, 1.49 ± 0.22 myocardial infarctions (MI), 0.71 ± 0.09 strokes, 0. 28 ± 0.05 deaths from CHD and 0.35 ± 0.05 deaths from CVD. No CV events were adjudicated in this subgroup during follow-up. Conclusions: RYGB significantly improves CV risk and prevents the occurrence of CV events. For similar weight loss, diabetic and elder patients experience a superior CV risk improvement and may have additional CV benefits after bariatric surgery.

Massive lower gastrointestinal bleeding from idiopathic ileocolonic varix: report of a case.

Idiopathic varices of the entire colon are very rare. We report on a 64-year-old patient with massive lower gastrointestinal hemorrhage from an extensive ileocolonic varix. Diagnosis was established by colonoscopy. The patient underwent an emergency ileocolectomy with satisfactory results. This rare case shows the importance of colonoscopy in the evaluation of patients with lower gastrointestinal hemorrhage and reminds us that sometimes the diagnosis is not what we expect. Recognition of this abnormality is important because varices may be the cause of massive lower gastrointestinal hemorrhage.