Short- and long-term follow-up of living kidney donors

Analysis of sexual dysfunction development among male and female living kidney donors

INTRODUCTION

Living kidney donations (LKDs) face a persistent demand for patients with end-stage renal disease, emphasizing the importance of LKDs' growth and success. Although living kidney donors generally exhibit excellent survival rates, little research has explored the development of long-term sexual dysfunction following LKD.

OBJECTIVES

This study aimed to analyze differences in 5-year sexual dysfunction outcomes between male and female living kidney donors, utilizing the TriNetX database, a federated network of electronic medical records from multiple U.S. healthcare organizations.

METHODS

A propensity score-matched cohort study compared 45-year sexual dysfunction outcomes in adult male and female living kidney donors from December 2013 to December 2022. Cohorts were matched on age; sex; race and ethnicity; diabetes, cardiovascular, genitourinary, and psychiatric comorbidities; lifestyle-related factors; and medications that may impact normal sexual functioning. Primary outcomes included hazard ratio (HR) for decreased libido, sexual dysfunction (composite of male erectile dysfunction, ejaculatory disorders, vaginismus/dyspareunia, infertility, orgasmic disorders, arousal/desire disorders), and sexually transmitted diseases. Secondary outcomes assessed sex counseling and interpersonal relationship issues with spouses or partners.

RESULTS

The matched cohorts included 2315 patients each (male, female), and the mean age was 42.3 ± 12.5 years. At 5 years, male donors had a significantly higher HR for sexual dysfunction (HR, 3.768; 95% confidence interval, 1.929-7.358). Erectile dysfunction occurred in 1% of male patients, while vaginismus/dyspareunia affected <1% of female patients. Other sexual disorders, decreased libido, sexually transmitted diseases, and incidences of sexual and interspousal counseling were not significantly different.

CONCLUSION

Male living kidney donors faced a higher risk of developing sexual dysfunction 5 years after donation. While LKD remains a safe and viable alternative, clinicians and donors should be mindful of the potential association with sexual dysfunction postdonation. Further research may enhance support for the well-being of living kidney donors.

Metabolic effects of kidney donation: A Bayesian analysis of matched cohorts

The kidney is a notable site of glycolysis, gluconeogenesis, and fatty acid oxidation. Loss of a kidney after kidney donation might, therefore, affect the glucose and lipid metabolism of the donors. This matched cohort study investigated the effect of nephrectomy on glucose and lipid metabolisms using Bayesian hypothesis testing. There were 77 pairs of matched donor-control pairs in the present study. Clinical and laboratory data of the participants, at baseline and 1-year, were extracted from electronic medical records. Comparisons between donor and control groups were performed using the Bayesian independent samples t-test or Bayesian Mann-Whitney test. The Bayes Factor for alternative hypothesis over null hypothesis (BF₁₀ ) was used to compare the two competing hypotheses. The BF₁₀ of 3 or more was considered evidence for the alternative hypothesis. Comparing changes from baseline to 1-year between donors and controls, the BF₁₀ of triglycerides, high-density lipoprotein cholesterol (HDL-C), triglyceride-glucose (TyG) index of insulin resistance, and estimated glomerular filtration rate (eGFR) were 7.95, 3.96, 30.13, and 1.32 x 10⁴¹ , respectively signifying that the change of these variables in the donors differed from those in the controls (alternative hypothesis). Triglyceride, HDL-C, and TyG index of the donors increased more than those of the controls while eGFR of the donor decreased more than that of the controls. Our data suggest that triglycerides and insulin resistance increase after donor nephrectomy. Kidney donors should be informed about these metabolic changes and should adhere to lifestyle recommendations that may mitigate insulin resistance.

The Alteration of Pro-inflammatory Cytokines and Oxidative Stress Markers at Six-Month Post-living Kidney Donation

Donors have a higher risk of developing chronic kidney disease than the general population. Some mechanisms mediated by pro-inflammatory cytokines and oxidative stress may be involved as risk factors. The objective of the study was to evaluate the behavior of pro-inflammatory cytokines and oxidative stress markers in living renal donors with a 6-month follow-up. A single prospective cohort was performed in 88 renal donors. At the end of the follow-up, the levels of lipoperoxides, 6.52 ± 1.12 mM, and 8-isoprostanes, 63.75 ± 13.28 pg/mL, were lower than before donation, 10.20 ± 3.95 mM (p < 0.001) and 67.54 ± 9.64 pg/mL (p = 0.026), respectively. Initial levels of nitric oxide (NO), 356.09 ± 59.38 μM increased at the end of the follow-up, 467.08 ± 38.74 μM (p < 0.001). It was observed in the final determination of donors decreased activity of antioxidant enzymes superoxide dismutase (SOD), 0.74 ± 0.57 U/L and glutathione peroxidase (GPx), 556.41 ± 80.37 nmol, in comparison with the levels obtained in the initial determination, 1.05 ± 0.57 U/L (p < 0.001) and 827.93 ± 162.78 nmol (p < 0.001), respectively. The pro-inflammatory cytokines, Tumor necrosis factor alpha and interleukin-6 showed no differences at 6 months after donation. The enzyme oxoguanine glycosylase (hOGG1) responsible for repairing oxidative damage to DNA, showed a decrease in its concentration at the end of the study in donor men, 0.40 ± 0.21 ng/mL compared to the initial levels, 0.55 ± 0.32 ng/mL (p = 0.025). The marker, 8-hydroxy-2-deoxyguanosine (8-OHdG) exhibited an increase in donor men at the final determination 2.28 ± 1.99 ng/mL, compared to the concentration before donation, 1.72 ± 1.96 ng/mL (p < 0.001). We found significant changes in the markers of the oxidative state with increased NO and 8-OHdG, as well as a significant decrease in the antioxidant defenses SOD, GPx, and in the DNA repair enzyme in living renal donors after 6 months of follow-up.

Survival in Living Kidney Donors: An Australian and New Zealand Cohort Study Using Data Linkage

Supplemental Digital Content is available in the text.

Background.

Living kidney donors are a highly selected healthy population expected to have high survival postdonation, but mortality studies are limited. Our study aimed to compare mortality in living kidney donors with the general population in Australia and New Zealand, hypothesizing that donor survival would exceed average survival.

Methods.

All living kidney donors in Australia, 2004–2013, and New Zealand, 2004–2012, from the Australian and New Zealand Living Kidney Donor Registry were included. We ascertained primary cause of death from data linkage with national death registers. Standardized mortality ratios and relative survival were estimated, matching on age, sex, calendar year, and country.

Results.

Among 3253 living kidney donors, there were 32 deaths over 20 331 person-years, with median follow-up 6.2 years [interquartile range: 3.9–8.4]. Only 25 donors had diabetes-fasting blood sugar level predonation, of which 3 had impaired glucose tolerance. At discharge, the median creatinine was 108 µmol/L and estimated glomerular filtration rate was 58 mL/min/1.72 m². Four deaths occurred in the first year: 2 from immediate complications of donation, and 2 from unrelated accidental causes. The leading cause of death was cancer (n = 16). The crude mortality rate was 157 (95% confidence interval [CI], 111-222)/100 000 person-y, and the standardized mortality ratio was 0.33 (95% CI, 0.24-0.47). The 5-year cumulative relative survival was 1.019 (95% CI, 1.014-1.021), confirming that the survival probability in living kidney donors was 2% higher relative to the general population.

Conclusions.

As expected, mortality in living kidney donors was substantially lower than the general population and is reassuring for potential donor counseling. The Living Donor Registry only captured a third of the deaths, highlighting the benefit of data linkage to national death registries in the long-term follow-up of living kidney donors.

Prevalence and risk factors of hypertension following nephrectomy in living kidney donors

Living donor kidney transplantation is the treatment of choice for the patients with end-stage renal disease, especially where deceased donor programs are limited. There are limited data on the outcomes of living kidney donors (LKD) from developing countries, especially from North Africa. The aim of this study is to evaluate the prevalence of hypertension (HTN) in LKD and to analyze its risk factors. This is a longitudinal monocentric study, and the donors who underwent nephrectomy for donation between 2006 and 2015 were included. Ninety-two donors were assessed. The mean age at the time of nephrectomy was 42.8 ± 10 years (21-68 years). The sex ratio was 0.6. At the time of donation, the median systolic blood pressure was 120 mm Hg and the median diastolic blood pressure was 70 mm Hg. HTN was noted in 4% of donors. The median follow-up duration was 26 months. Two years after donation, the prevalence of HTN was 28% in the study group (8% male and 20% female). The mean time to development of HTN was 16 months. Associations between HTN after donation and the cardiovascular family history, age >40 years, HTN, obesity, android obesity, glomerular filtration rate GFR <90 mL/min/1.73 m², perioperative HTN, and dyslipidemia were noted. The multivariate analysis showed that obesity at the time of donation was a risk factor for HTN (odds ratio = 4.8; P = 0.04). Obese donor [body mass index (BMI) ≥30)] has higher risk of HTN after nephrectomy than nonobese donor.