Obesity and kidney transplantation

A holistic review of sodium intake in kidney transplant patients: More questions than answers

Kidney transplantation (KT) is the best treatment option for end-stage kidney disease (ESKD). Acute rejection rates have decreased drastically in recent years but chronic kidney allograft disease (CKAD) is still an important cause of allograft failure and return to dialysis. Thus, there is unmet need to identify and reverse the cause of CKAD. Additionally, cardiovascular events after KT are still leading causes of morbidity and mortality. One overlooked potential contributor to CKAD and adverse cardiovascular events is increased sodium/salt intake in kidney transplant recipients (KTRs). In general population, the adverse effects of high sodium intake are well known but in KTRs, there is a paucity of evidence despite decades of experience with KT. Limited research showed that sodium intake is high in most KTRs. Moreover, excess sodium intake is associated with elevated blood pressure and albuminuria in some studies involving KTRs. There is also experimental evidence suggesting that increased sodium intake is associated with histologic graft damage. Critical knowledge gaps still remain, including the exact amount of sodium restriction needed in KTRs to optimize outcomes and allograft survival. Additionally, best methods to measure sodium intake and practices to follow-up are not clarified in KTRs. To meet these deficits, prospective long term studies are warranted in KTRs. Moreover, preventive measures must be determined and implemented both at individual and societal levels to achieve sodium restriction in KTRs.

Timing Considerations for Sleeve Gastrectomy in Kidney Transplant Patients: A Single Center Evaluation

Current scientific literature is deficient in detailing the optimal timing for conducting bariatric surgery in relation to kidney transplantation. In this study, we performed a retrospective evaluation of kidney transplant recipients with BMI >35 kg/m2. It aimed to provide data on those who received both sleeve gastrectomy (SG) and kidney transplantation (KT) simultaneously, as well as on patients who underwent SG and KT at different times, either before or after. In addition, the acceptance levels of the bariatric surgery among different scenarios were assessed. Our findings demonstrated that combined KT and SG led to successful weight loss, in contrast to undergoing kidney transplant alone, while maintaining comparable rates of graft and patient survival. Weight loss was similar between recipients who had a combined operation and those who underwent SG following the transplant. Additionally, over a median time frame of 1.7 years, patients who underwent SG before KT exhibited a statistically significant reduction in BMI at the time of the transplant. Notably, our study highlights that patients offered the combined procedure were significantly more likely to undergo SG compared to those for whom SG was presented at a different operative time than the transplant.

Cardiometabolic comorbidities and complications of obesity and chronic kidney disease (CKD)

Obesity and chronic kidney disease are two ongoing progressive clinical pandemics of major public health and clinical care significance. Because of their growing prevalence, chronic indolent course and consequent complications both these conditions place significant burden on the health care delivery system especially in developed countries like the United States. Beyond the chance coexistence of both of these conditions in the same patient based on high prevalence it is now apparent that obesity is associated with and likely has a direct causal role in the onset, progression and severity of chronic kidney disease. The causes and underlying pathophysiology of this are myriad, complicated and multi-faceted. In this review, continuing the theme of this special edition of the journal on " The Cross roads between Endocrinology and Nephrology" we review the epidemiology of obesity related chronic kidney disease (ORCKD), and its various underlying causes and pathophysiology. In addition, we delve into the consequent comorbidities and complications associated with ORCKD with particular emphasis on the cardio metabolic consequences and then review the current body of evidence for available strategies for chronic kidney disease modulation in ORCKD as well as the potential unique role of weight reduction and management strategies in its improvement and risk reduction.

Obesity is associated with a higher incidence of rejection in patients on belatacept: A pooled analysis from the BENEFIT/BENEFIT-EXT clinical trials

Though belatacept is administered with a weight-based dosing schema, there has been higher clearance reported in obese patients. Therefore, we evaluated the association between body mass index (BMI) and transplant outcomes in kidney transplant recipients who were randomized to cyclosporine- or belatacept-based immunosuppression in the BENEFIT and BENEFIT-EXT randomized clinical trials. A total of 666 and 543 patients underwent randomization and transplantation in BENEFIT and BENEFIT-EXT, respectively, of which 1056 had complete data and were included in this analysis. Patients were grouped categorically according to BMI: <25, 25 to <30, and ≥30 kg/m2. BMI did influence both the incidence and severity of acute rejection. Obese patients with BMI >30 kg/m2 in the low intensity belatacept group experienced significantly more rejection at 12 months than did patients with BMI <25 kg/m2 or BMI 25 to <30 kg/m2. In both the moderate intensity belatacept and low intensity belatacept groups, obese patients with BMI >30 kg/m2 experienced significantly more severe acute rejection than did patients with BMI < 25 kg/m2 or BMI 25 to <30 kg/m2. These results suggest that obese kidney transplant recipients are at an increased risk for acute rejection when under belatacept-based immunosuppression when compared to nonobese patients.

KDOQI Commentary on the KDIGO 2022 Update to the Clinical Practice Guideline for Diabetes Management in CKD

The Kidney Disease: Improving Global Outcomes (KDIGO) guideline for diabetes management in chronic kidney disease (CKD) was updated in 2022, just 2 years after the previous update. The need for this rapid update is reflective of the recent and unprecedented positive results of numerous clinical trials aimed at reducing kidney and cardiovascular morbidity and mortality in people with diabetes. The Kidney Disease Outcomes Quality Initiative (KDOQI) work group for diabetes in CKD, convened by the National Kidney Foundation, provides herein a commentary on these changes, particularly the implications for health care in the United States. Changes to the KDIGO guideline mirror the evolution of sodium/glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 receptor agonists from purely antihyperglycemic agents to cardiorenal-metabolic therapeutics, and the lower estimated glomerular filtration rate of≥20mL/min/1.73m2 for SGLT2 inhibitor initiation. New data have also brought the addition of the first-in-class, Federal Drug Administration-approved nonsteroidal mineralocorticoid receptor antagonist finerenone as an agent to reduce cardiorenal end points. While there has been significant progress in innovation, there remain serious challenges to implementation, particularly in the United States where inequities in insurance coverage and high costs limit their use, particularly in vulnerable populations, ultimately widening health care disparities.

Impact of Obesity on Kidney Transplant Outcomes in Older Adults

BACKGROUND

The prevalence of obesity in older patients undergoing kidney transplantation is increasing. Older age and obesity are associated with higher risks of complications and mortality post-transplantation. The optimal management of this group of patients remains undefined.

METHODS

We retrospectively analyzed the United Network for Organ Sharing database of adults ≥70 years of age undergoing primary kidney transplant from January 1, 2014, to December 31, 2022. We examined patient and graft survival stratified by body mass index (BMI) in 3 categories, <30 kg/m2, 30 to 35 kg/m2, and >35 kg/m2. We also analyzed other risk factors that impacted survival.

RESULTS

A total of 14,786 patients ≥70 years underwent kidney transplantation. Of those, 9,731 patients had a BMI <30 kg/m2, 3,726 patients with a BMI of 30 to 35 kg/m2, and 1,036 patients with a BMI >35 kg/m2. During the study period, there was a significant increase in kidney transplants in patients ≥70 years old across all BMI groups. Overall, patient survival, death-censored graft survival, and all-cause graft survival were lower in obese patients compared with nonobese patients. Multivariable analysis showed worse patient survival and graft survival in patients with a BMI of 30 to 35 kg/m2, a BMI >35 kg/m2, a longer duration of dialysis, diabetes mellitus, and poor functional status.

CONCLUSION

Adults ≥70 years should be considered for kidney transplantation. Obesity with a BMI of 30 to 35 kg/m2 or >35 kg/m2, longer duration of dialysis, diabetes, and functional status are associated with worse outcomes. Optimization of these risk factors is essential when considering these patients for transplantation.

Obesity-Related Kidney Disease: Current Understanding and Future Perspectives

Obesity is a serious chronic disease and an independent risk factor for the new onset and progression of chronic kidney disease (CKD). CKD prevalence is expected to increase, at least partly due to the continuous rise in the prevalence of obesity. The concept of obesity-related kidney disease (OKD) has been introduced to describe the still incompletely understood interplay between obesity, CKD, and other cardiometabolic conditions, including risk factors for OKD and cardiovascular disease, such as diabetes and hypertension. Current therapeutics target obesity and CKD individually. Non-pharmacological interventions play a major part, but the efficacy and clinical applicability of lifestyle changes and metabolic surgery remain debatable, because the strategies do not benefit everyone, and it remains questionable whether lifestyle changes can be sustained in the long term. Pharmacological interventions, such as sodium-glucose co-transporter 2 inhibitors and the non-steroidal mineralocorticoid receptor antagonist finerenone, provide kidney protection but have limited or no impact on body weight. Medicines based on glucagon-like peptide-1 (GLP-1) induce clinically relevant weight loss and may also offer kidney benefits. An urgent medical need remains for investigations to better understand the intertwined pathophysiologies in OKD, paving the way for the best possible therapeutic strategies in this increasingly prevalent disease complex.