Impact of Preoperative Abdominal Visceral Adipose Tissue Area and Nutritional Status on Renal Function After Donor Nephrectomy in Japanese Living Donors for Renal Transplantation

The Effect of PNI Score on Renal Prognosis and Graft Rejection After Kidney Transplantation

BACKGROUND

Determining effective ways to make prognostic predictions after kidney transplantation of patients is essential for the management of patients. This study examines how the PNI score affects renal outcomes after kidney transplantation. The potential impact of PNI on renal function beyond the overall nutritional status was also examined.

METHODS

In this retrospective study, 100 kidney transplant patients were divided into three groups according to PNI scores: low (<40), intermediate (40-45) and high (>45). Demographic characteristics, clinical parameters, serum creatinine levels, estimated glomerular filtration rate (eGFR) and parenchymal thickness were evaluated. Logistic regression analysis was applied for the risk of graft rejection. Patients who were followed up for at least 6 months after kidney transplantation and had complete clinical data were included in the study. The mean follow-up period was 36 months (range: 6-60 months).

RESULTS

There was no statistically significant correlation between PNI scores and renal function (P > .05). The mean creatinine level was 1.73 ± 1.11 mg/dL in the low PNI group and 1.37 ± 0.52 mg/dL in the high PNI group. Although this difference was close to the limit of statistical significance, it was not significant (P = .083). In logistic regression analysis, no significant effect of PNI score on graft rejection was observed (OR: 1.0015, 95% CI: 0.7975-1.2576, P = .9899). However, age (OR: 0.9247, P = .0347) and serum creatinine levels (OR: 2.8396, P = .0151) significantly affected the risk of graft rejection. No significant effect of PNI score on complication rates was observed.

CONCLUSIONS

This study demonstrated that PNI score alone is not a sufficient predictor of renal prognosis and graft rejection risk after kidney transplantation. Factors such as age and serum creatinine levels were found to be more predictive of the risk of graft rejection.

Higher abdominal fat area associates with lower donor kidney function before and after living kidney donation

Central body fat distribution affects kidney function. Abdominal fat measurements using computed tomography (CT) may prove superior in assessing body composition-related kidney risk in living kidney donors. This retrospective cohort study including 550 kidney donors aimed to determine the association between CT-measured abdominal fat areas and kidney function before and after donor nephrectomy. Donors underwent glomerular filtration rate measurements (125I-Iothalamate, mGFR) before and 3 months after donation. Linear regression analyses with body surface area (BSA)-standardized and crude mGFR were performed to assess the association of height-indexed tomographic fat measurements with kidney function. In age-, and sex-adjusted analyses higher levels of total abdominal, visceral, subcutaneous, and intramuscular adipose tissue index were significantly associated with lower mGFR levels before donation (BSA-standardized mGFR: visceral adipose tissue index: Βeta=-0.11, p < 0.001, subcutaneous: Βeta=-0.10, p < 0.001, intramuscular: Βeta=-1.18, p < 0.001, total abdominal: Βeta=-0.07, p < 0.001). Higher tomographic abdominal fat is associated with lower BSA-standardized mGFR after donation and a greater decrease in mGFR between screening and 3 months post-donation. This study shows that CT-measured abdominal fat area is associated with kidney function before and after living kidney donation.

Follow-up After Donor Nephrectomy in Living Kidney Donors: How to Manage Living Kidney Donors Postoperatively

BACKGROUND/AIM

This study investigated the follow-up rate of living kidney donors and explored the factors related to continuous follow-up and remnant renal function, enabling the optimal management of living kidney donors.

PATIENTS AND METHODS

We retrospectively evaluated 180 living kidney donors who underwent donor nephrectomies at our institute. Clinical information was obtained from medical charts, and remnant renal function was defined as the estimated glomerular filtration rate 12 months after donor nephrectomy.

RESULTS

Overall, 6/180 donors (3.3%) were lost to follow-up within a year, and the follow-up rate gradually declined yearly. Independent risk factors for loss to follow-up included a follow-up period <60 months and graft survival of the recipient (p=0.002 and p=0.043, respectively). Recipient survival was correlated with loss to follow-up; however, this was not significant (p=0.051). Regarding remnant renal function, age ≥60 years, preoperative estimated glomerular filtration rate <74 ml/min/1.73 m2, and a Δsingle-kidney estimated glomerular filtration rate <9.3 ml/min/1.73m2 were independent risk factors for poorly preserved remnant renal function (p=0.036, p<0.0001, and p<0.0001, respectively). Using propensity score matching to adjust for preoperative factors, a Δsingle-kidney estimated glomerular filtration rate <9.3 ml/min/1.73 m2 was the only significant postoperative factor for poorly preserved remnant renal function (p=0.023).

CONCLUSION

An increased 5-year follow-up rate could lead to an increase in long-term follow-up, and recipient prognosis may be correlated with the living kidney donor follow-up status. Furthermore, Δsingle-kidney estimated glomerular filtration rate was identified as a factor for establishing the optimal precision follow-up management of living kidney donors.

Lean body mass in living kidney donors impacts postoperative renal function

PURPOSE

A living donor kidney transplant is the optimal treatment for chronic renal impairment. Our objective is to assess if lean skeletal muscle mass and donor factors such as body mass index, hypertension, and age impact on renal function following donor nephrectomy.

METHODS

Potential donors undergo CT angiography as part of their work-up in our institution. Using dedicated software (Horos®), standardized skeletal muscle area measured at the L3 vertebrae was calculated. When corrected for height, skeletal muscle index can be derived. Skeletal muscle mass index below predefined levels was classified as sarcopenic. The correlation of CT-derived skeletal muscle index and postoperative renal function at 12 months was assessed. Co-variables including donor gender, age, body mass index (BMI), and presence of pre-op hypertension were also assessed for their impact on postoperative renal function.

RESULTS

275 patients who underwent living donor nephrectomy over 10 years were included. Baseline pre-donation glomerular filtration rate (GFR) and renal function at one year post-op were similar between genders. 29% (n = 82) of patients met the criteria for CT-derived sarcopenia. Sarcopenic patients were more likely to have a higher GFR at one year post-op (69.3 vs 63.9 mL/min/1.73 m2, p < 0.001). The main factors impacting better renal function at one year were the presence of sarcopenia and younger age at donation.

CONCLUSION

When selecting donors, this study highlights that patients with low skeletal mass are unlikely to underperform in terms of recovery of their renal function postoperatively at one year when compared to patients with normal muscle mass and should not be a barrier to kidney donation.

A Low Prognostic Nutritional Index Is a Risk Factor for High Peritoneal Transport Status in Patients Undergoing Peritoneal Dialysis

OBJECTIVES

A high peritoneal transport status is a risk factor for mortality and causes technical failure in patients on peritoneal dialysis (PD). High peritoneal transport status is associated with malnutrition and inflammation in patients with PD. The prognostic nutritional index (PNI) is a marker determined by the serum albumin level and lymphocyte count in the peripheral blood. The aim of this study is to investigate the association between PNI and high peritoneal transport status in patients with PD.

METHODS

We retrospectively investigated patients with PD from January 1, 2013 to May 31, 2020, in 4 PD centers. Patients with PD were divided into 2 groups according to PNI quartiles: the low PNI group (PNI ≤ 36.6) and the high PNI group (PNI > 36.6). The demographics and clinical and laboratory baseline data of the 2 groups were collected and compared. The association between PNI and high peritoneal transport status was analyzed by multivariate logistic regression analysis.

RESULTS

A total of 404 patients with PD were enrolled in our study. A total of 77 (19.06%) patients had high peritoneal transport status. After adjusting for age, sex, body mass index, hypertension, diabetes mellitus, residual urine volume, current smoking status, pre-existing cardiovascular disease, hemoglobin, white blood cell count, triglycerides, and intact parathyroid hormone, low PNI levels were significantly associated with high peritoneal transport status (odds ratio 3.42, 95% confidence interval 1.82-5.18, P = .0056). Subgroup analysis showed that there was no interaction among PNI and age, sex, diabetes, body mass index, pre-existing cardiovascular disease, or current smoking.

CONCLUSION

As a marker for malnutrition and inflammation, a low level of PNI is an independent risk factor for high peritoneal transport status in patients with PD.

The Role of Prognostic Nutrition Index in Predicting Hospitalization of Patients With Heart Failure With Mildly Reduced Ejection Fraction

Background The prognostic nutritional index (PNI), consisting of albumin and lymphocyte counts, has been associated with satisfactory predictive values ​​for in-hospital mortality or clinical follow-up outcomes in acute situations. In this study, we aimed to evaluate the use of PNI for the prediction of hospital admission in individuals with mildly reduced ejection fraction heart failure (HFmrEF). Methodology This retrospective study was conducted between January 2019 and May 2022 and included 200 patients with HFmrEF detected by transthoracic echocardiography. Data from hospitalized patients (group 1) and outpatients (group 2) were compared. Results In the multivariable regression analysis, brain natriuretic peptide (odds ratio (OR) = 1.001; 95% confidence interval (CI) = 1.000-1.001, p = 0.001) and PNI (OR = 0.783; 95% CI = 0.720-0.853; p < 0.001) were independent predictors of hospital admission in patients with HFmrEF. The PNI value was statistically significantly higher in group 2 (52.36 ± 5.36) than in group 1 (38.3 ± 8.63, p < 0.001). The PNI value <46.75 is a predictor of hospitalization in patients with HFmrEF, with 86% sensitivity and 88% specificity. Conclusions Lower PNI levels predict hospital admission in HFmrEF patients. This measure, which can be easily evaluated in daily cardiological practice, allows for quick and precise decisions for hospitalization.

Visceral Adipose Tissue Influence on Health Problem Development and Its Relationship with Serum Biochemical Parameters in Middle-Aged and Older Adults: A Literature Review

Background

The amount of visceral adipose tissue (VAT) tends to increase with age and is associated with several health problems, such as cardiometabolic diseases, increased infections, and overall mortality.

Objectives

This review provides a general assessment of how visceral adiposity correlates with the development of health problems and changes in serum biochemical parameters in middle-aged and older adults.

Methods

We searched specific terms in the Virtual Health Library (VHL) databases for VAT articles published in the English language between 2009 and 2019 related to older adults.

Results

The search found twenty-three publications in this period, of which nine were excluded. The publications had a population aged between 42 and 83 years and correlated the VAT area ratio with several comorbidities (such as pancreatitis, depression, cancer, and coronary heart disease) and serum biochemical parameters.

Conclusion

Further research on the association between visceral obesity and the emergence of health problems and the relationship between VAT and changes in serum biochemical parameters in older individuals should deepen the understanding of this connection and develop preventive actions.

Pre-transplant morphometry by computed tomography scan and post-transplant dialysis risk in overweight or obese kidney transplant recipients

PURPOSE

Adipose distribution and sarcopenia could better assess kidney transplantation outcomes than body mass index (BMI) and have been poorly evaluated among obese and overweight recipients. We aimed to evaluate morphometric radiologic markers to predict post-operative dialysis within this population.

METHODS

We conducted a retrospective study including patients with a BMI > 25 kg/m² undergoing kidney transplantation during 5 years. Subcutaneous adipose tissue surface (SAT), visceral adipose tissue surface (VAT), and psoas surface were measured on CT scans sections. A model predictive of post-transplantation dialysis was elaborated through a multivariable logistic regression and was compared to a model including only BMI.

RESULTS

Overall, 248 patients were included whom mean (SD) BMI and age were, respectively, 29.7 kg/m2 (3.6) and 56 years (12.7). Of them, 83 (33.5%) needed dialysis: 14 (5.7%) for primary kidney failure and 69 (27.8%) for delayed kidney function. On multivariable analysis, SAT, VAT and deceased donor were significantly associated with post-operative dialysis (respectively, OR [95%CI]:1.6 [1.1-2.6], 1.6[1.1-2.6], and 7.5 [1.6-56]). The area under the curve of this predictive model was 0.70 versus 0.64 for a BMI-based model.

CONCLUSION

High VAT and SAT were associated with post-transplantation dialysis. A predictive model based on these morphometrics could provide a better appreciation of graft recovery after transplantation among obese and overweight recipients. External validation is needed.

The impact of visceral adipose tissue on post -operative renal Function after Radical Nephrectomy for renal cell carcinoma

BACKGROUND

The objective of this study was to evaluate the usefulness of pre-operative visceral (VAT) and subcutaneous adipose tissue (SAT) evaluation in the prediction of Acute Kidney Injury (AKI) and decrease of eGFR at 12 months after radical nephrectomy (RN).

METHODS

We relied on 112 patients who underwent RN between January 2010 and March 2017 at a single institution. Images from the pre-operatory CT scan were analyzed and both SAT and VAT assessments were carried out on a cross-sectional plane. eGFR was measured before surgery, at 7 days, and 12 months after surgery. ROC analysis was used to compare the diagnostic value of BMI, VAT ratio, and abdominal circumference in predicting AKI. Logistic regression models were fitted to predict the new onset of AKI, and the progression from chronic kidney disease (CKD) stage 1-3a to CKD stage 3b or from 3b to 4 at 12 months follow-up. Two logistic regression models were also performed to assess the predictors for AKI and CKD stage progression. The predictive accuracy was quantified using the receiver operating characteristic-derived area under the curve.

RESULTS

Sixty-six patients (58.9%) had AKI after RN. Thirty-five (31.3%) patients were upgraded to CKD IIIb or from CKD stage IIIb to CKD IV. In the ROC analysis, VAT% performed better than the BMI and abdominal circumference (AUC = 0.66 vs 0.49 and 0.54, respectively). At multivariable analyses, VAT reached an independent predictor status for AKI (OR: 1.03) and for CKD stage at 12 months Follow-up (OR: 1.05). Inclusion of VAT% into the multivariable models was associated with the highest accuracy both for AKI (AUC = 0.700 vs 0.570) and CKD stage progression (AUC = 0.848 vs 0.800).

CONCLUSIONS

In patients undergoing RN, preoperative visceral adipose tissue ratio significantly predicts AKI incidence and is significantly predictive of 12 months CKD stage worsening.

Prognostic nutritional index predicts acute kidney injury and mortality of patients in the coronary care unit

The current study aimed to investigate whether prognostic nutritional index (PNI) is an independent predictor of acute kidney injury (AKI) and mortality of patients in the coronary care unit (CCU). In the present two-stage observational study of patients in the CCU, 6,444 patients from the Medical Information Mart for Intensive Care (MIMIC) III database were first enrolled (test cohort), after which 412 patients from Zhongnan Hospital of Wuhan University were recruited in the validation cohort. AKI was defined based on the Kidney Disease Improving Global Outcomes AKI criteria. The primary endpoint was the incidence of AKI stratified by severity, while the second endpoint included in-hospital mortality and 2-year mortality. In the test cohort, 4,457 (69.2%) patients developed AKI during hospitalization. Following multivariable adjustment, the highest quartile of the PNI value was associated with a 1.8-fold increased risk of AKI compared with the lowest quartile. For the prediction of AKI, the area under the receiver operating characteristic curve outperformed the acute physiology score III score and clinical model in patients with or without preexisting chronic kidney disease, and this was further validated in the hospital cohort used in the present study. A total of 2,219 patients suffered mortality during the 2-year follow-up, and PNI was indicated to independently predict the risk of in-hospital mortality and 2-year mortality in the test cohort and in the validation cohort. Decision curve analysis indicated that the PNI values were clinically useful; Therefore, the current study demonstrated that the PNI value is an independent predictor of AKI and mortality in patients within the CCU.

Latest developments in living kidney donation

PURPOSE OF REVIEW

Although the first successful kidney transplantation 65 years ago was performed with a living donor kidney, the number of living donor kidney transplantations has increased especially during the last 2 decades. The enlargement of living donor programs was made possible by new modes of living donation and by expansion of the living donor pool. At the same time, the long-term risks of kidney donation have been better delineated. In this review, the latest developments on these topics are summarized.

RECENT FINDINGS

While the results of ABO-incompatible living kidney transplantation are superior to those of deceased donor transplantation, recent meta-analyses show a reduced patient and graft survival as compared with ABO compatible transplantation as well as increased risk of severe infection and bleeding. Kidney paired donation programs can be extended by including compatible couples and by advanced donation, although the latter raises ethical concerns. Living donors appear to have a higher risk of end-stage renal disease and this is especially true for obese donors and probably also for black donors with an APOL1 high-risk genotype. The importance of psychosocial outcomes after living kidney donation is increasingly recognized.

SUMMARY

Living donor kidney transplantation remains the optimal treatment option for patients with end-stage renal disease. To increase the donor pool, a well developed paired kidney donation program and sufficient reimbursement of costs associated with donation are essential ingredients. Other ways of expanding the donor pool, such as ABO-incompatible transplantation, use of higher risk donors, providing donors with financial incentives and advanced donation are associated with medical, ethical and logistical complications. There should be a careful selection and follow-up of living kidney donors with attention for medical consequences as well as for psychosocial outcomes.

Evaluation of Preoperative Abdominal Adipose Tissue-, Inflammation-, Muscle Mass-, and Nutritional Status-based Prognostic Markers to Assess Renal Dysfunction in Living Kidney Donors

BACKGROUND

Living kidney donors (LKDs) are at high risk of renal dysfunction after undergoing a donor nephrectomy (DN), resulting in poor prognosis associated with the development of cardiovascular or cerebrovascular disease. Decreasing this risk can improve the survival rate of LKDs. We investigated the effects of preoperative conditions in LKDs on renal dysfunction after DN using abdominal adipose tissue, inflammation, nutritional status, and muscle mass as markers for this assessment.

METHODS

Our retrospective study included 79 LKDs. Body composition markers were assessed using preoperative unenhanced computed tomographic images. Inflammation- and nutritional status-based markers were assessed using preoperative laboratory blood tests. The association between each marker was investigated, and prognostic markers for renal dysfunction after DN were identified.

RESULTS

The LKDs in this cohort comprised 30 men and 49 women. The median age at the time of DN and the preoperative estimated glomerular filtration rate were 58 years and 81.9 mL/min/1.73 m², respectively. Abdominal subcutaneous adipose tissue and muscle mass significantly differed between the sexes. Each adipose tissue-, inflammation-, nutritional status-, and muscle mass-based marker showed an association with each other. Abdominal visceral adipose tissue and nutritional status could be independent prognostic markers for renal dysfunction after DN.

CONCLUSIONS

Our findings suggest that the preoperative condition of LKDs (assessed using specific markers such as abdominal visceral adipose tissue mass per volume and nutritional status) could affect renal dysfunction after DN. Optimal preoperative management can lead to better outcomes in LKDs. Further research is needed to establish appropriate exercise programs and nutritional interventions.

Clinical Significance of Postoperative Nutritional Status as a Prognostic Factor in Kidney Transplant Recipients

BACKGROUND

Despite advancements in the management of kidney transplantation (KT), kidney transplant recipients (KTRs) have a higher risk of mortality than the age-matched general population. Improvement of long-term graft and patient survival is a significant issue. Therefore we investigated the effects of postoperative nutritional status on graft and patient survival and explored the predictive factors involved in nutritional status.

METHODS

Our retrospective study included 118 KTRs who underwent KT at our hospital. Clinical and laboratory data were obtained from medical charts. The prognostic nutritional index (PNI) was used to assess nutritional status. Changes in nutritional status after KT were monitored and the effect of nutritional status on graft and patient survival was investigated. The variables involved in nutritional status were also explored.

RESULTS

The KTRs in this cohort comprised 66 men and 52 women with a median age of 47 years at KT. There were 16, 32, and 22 cases of cadaveric, preemptive, and ABO-incompatible KTs, respectively. Postoperative PNI gradually improved and was stable from 6 months after KT. Although graft survival was regulated by ABO-compatibility, independent predictors for patient survival were history of dialysis, PNI, and serum-corrected calcium levels. Preemptive KT and inflammatory status contributed to PNI.

CONCLUSIONS

Nutritional status of KTRs improved over time after KT and could contribute to patient survival. Optimal nutritional educational programs and interventions can lead to better outcomes in KTRs. Further studies are needed to validate our results and develop appropriate nutritional educational programs, interventions, and exercise programs.