Impact Of Kidney Transplantation Research Articles

Vitamin D Metabolites Before and After Kidney Transplantation in Patients Who Are Anephric

Rationale & ObjectiveKidneys are vital for vitamin D metabolism and disruptions in both production and catabolism occur in chronic kidney disease. Although vitamin D activation occurs in numerous tissues, the kidneys are the most relevant source of circulating active vitamin D. This study investigates extrarenal vitamin D activation and the impact of kidney transplantation on vitamin D metabolism in patients who are anephric. Study DesignCase series. Setting & ParticipantsAdult patients with previous bilateral nephrectomy (anephric) not receiving active vitamin D therapy were evaluated at the time of (N=38) and 1 year after (N=25) kidney transplantation. Liquid chromatography–tandem mass spectrometry was used to measure vitamin D metabolites. Metabolic ratios were expressed CYP24A1 (24,25(OH)2D/25(OH)D) and CYP27B1 (1α,25(OH)2D/25(OH)D) as activities. Differences between evaluation timepoints were evaluated by paired Student’s t-test or Wilcoxon matched-pairs signed-rank test. FindingsAt time of transplantation, 1α,25(OH)2D was detectable in all patients (4 to 36 pg/mL). There was a linear relationship between 25(OH)D and 1α,25(OH)2D-levels (r=0.58, p<0.001) with 25(OH)D explaining 34% of the variation in 1α,25(OH)2D-levels. There were no associations between 1α,25(OH)2D and biointact PTH or FGF23. One year after transplantation, 1α,25(OH)2D levels recovered (+205%) and CYP27B1 activity increased (+352%). Measures of vitamin D catabolism, 24,25(OH)2D and CYP24A1 activity increased 3-5 fold. Also at 12 months after transplantation, 1α,25(OH)2D was positively correlated with PTH (rho=0.603, p=0.04), but not with levels of 25(OH)D or FGF23. LimitationsRetrospective, observational study design with a small cohort size. ConclusionsLow-normal levels of 1α,25(OH)2D was demonstrated in anephric patients, indicating production outside of the kidneys. This extrarenal CYP27B1 activity may be more substrate-driven than hormonally regulated. Kidney transplantation seems to restore kidney CYP27B1 and CYP24A1 activity, as evaluated by vitamin D metabolic ratios, resulting in both increased vitamin D production and catabolism. These findings may have implications for vitamin D supplementation strategies in the setting of kidney failure and transplantation.

Levels of Cell-Free DNA in Kidney Failure Patients before and after Renal Transplantation.

Circulating cell-free DNA (cfDNA) has diverse applications in oncological, prenatal, toxicological, cardiovascular, and autoimmune diseases, diagnostics, and organ transplantation. In particular, mitochondrial cfDNA (mt-cfDNA) is associated with inflammation and linked to early vascular ageing (EVA) in end-stage kidney failure (ESKF), which could be a noninvasive marker for graft rejection and organ damage. Plasma samples from 44 ESKF patients, of whom half (n = 22) underwent either conservative therapy (non-HD) or hemodialysis (HD) before kidney transplantation (KT). These samples were analyzed at baseline and two years after KT. cfDNA was extracted from plasma and quantified using the fluorometric method. qPCR was used to quantify and differentiate the fractions of mt-cfDNA and nuclear cfDNA (nc-cfDNA). mt-cfDNA levels in KT patients decreased significantly from baseline to two years post-KT (p < 0.0268), while levels of total cfDNA and nc-cfDNA did not differ. Depending on therapy modality (HD vs. non-HD) before KT, total cfDNA levels were higher in HD patients at both baseline (p = 0.0133) and two years post-KT (p = 0.0421), while nc-cfDNA levels were higher in HD only at baseline (p = 0.0079). Males showed a nonsignificant trend of higher cfDNA levels. Patients with assessed vascular fibrosis (p = 0.0068), either alone or in combination with calcification plus fibrosis, showed reduced mt-cfDNA post-KT (p = 0.0195). Changes in mt-cfDNA levels suggests the impact of KT on the inflammatory state of ESKF, as evidenced via its correlation with high sensitivity C-reactive protein after KT. Further studies are warranted to assess if cfDNA could serve as a noninvasive method for monitoring the response to organ transplantation and even for amelioration of EVA status per se.

Unraveling Intestinal Microbial Shifts in ESRD and Kidney Transplantation: Implications for Disease-Related Dysbiosis.

The composition of the gut microbiome is profoundly influenced by the accumulation of toxins in end-stage renal disease (ESRD) and specific medical treatments during kidney transplantation (KT). However, variations in results may arise due to factors such as genetics, dietary habits, and the strategy of anti-rejection therapy. Therefore, we conducted a 16S rRNA sequencing study to characterize intestinal microbiomes by using 75 fecal specimens obtained from 25 paired Chinese living donors (LDs) of kidneys and recipients before and after KT. Surprisingly, similar enterotypes were observed between healthy LDs and ESRD recipients. Nonetheless, following KT, the fecal communities of recipients exhibited distinct clustering, which was primarily characterized by Escherichia-Shigella and Streptococcus at the genus level, along with a reduction in the diversity of microbiota. To further explore the characteristics of gut microorganisms in early rejection episodes, two recipients with biopsy-proven borderline changes during follow-up were enrolled in a preliminary sub-cohort study. Our findings reveal a comparable construction of gut microbiota between ESRD patients and their healthy relatives while also highlighting the significant impact of KT on gut microbial composition.

Understanding the impact of pediatric kidney transplantation on cognition: A review of the literature.

Chronic kidney disease (CKD) is a relatively rare childhood disease that is associated with a wide array of medical comorbidities. Roughly half of all pediatric patients acquire CKD due to congenital anomalies of the kidneys and urinary tract, and of those with congenital disease, 50% will progress to end-stage kidney disease (ESKD) necessitating a kidney transplantation. The medical sequelae of advanced CKD/ESKD improve dramatically following successful kidney transplantation; however, the impact of kidney transplantation on neurocognition in children is less clear. It is generally thought that cognition improves following kidney transplantation; however, our knowledge on this topic is limited by the sparsity of high-quality data in the context of the relative rarity of pediatric CKD/ESKD. We conducted a narrative review to gauge the scope of the literature, using the PubMed database and the following keywords: cognition, kidney, brain, pediatric, neurocognition, intelligence, executive function, transplant, immunosuppression, and neuroimaging. There are few published longitudinal studies, and existing work often includes wide heterogeneity in age at transplant, variable dialysis exposure/duration prior to transplant, and unaccounted cofounders which persist following transplantation, including socio-economic status. Furthermore, the impact of long-term maintenance immunosuppression on the brain and cognitive function of pediatric kidney transplant (KT) recipients remains unknown. In this educational review, we highlight what is known on the topic of neurocognition and neuroimaging in the pediatric KT population.

Incident dementia in kidney transplantation recipients: a matched comparative nationwide cohort study in South Korea.

Recent studies have shown that patients with end-stage renal disease (ESRD) are at elevated risk of dementia. However, whether kidney transplantation (KT) lowers the risk for incident dementia remains unclear. From the Korean National Health Insurance Service database, we identified incident KT recipients aged ≥40 years without any history of dementia between 2007 and 2015. We also established a pair of age-, sex-, and inclusion year-matched control cohorts of patients with incident dialysis-dependent ESRD and members of the general population (GP) without a history of dementia, respectively. Cases of incident all-cause dementia, including Alzheimer disease (AD), vascular dementia (VD), and other kinds of dementia, were obtained from baseline until December 31, 2017. We followed 8,841 KT recipients, dialysis-dependent ESRD patients, and GP individuals for 48,371, 28,649, and 49,149 patient- years, respectively. Their mean age was 52.5 years, and 60.6% were male. Over the observation period, 55/43/19 KT recipients, 230/188/75 dialysis-dependent ESRD patients, and 38/32/14 GP individuals developed all-cause dementia/AD/VD. The risks of incident all-cause dementia, AD, and VD in KT recipients were similar to those in GP (hazard ratio: 0.74 [p = 0.20], 0.74 [p = 0.24], and 0.59 [p = 0.18], respectively) and significantly lower than those in dialysis-dependent ESRD patients (hazard ratio: 0.17 [p &lt; 0.001], 0.16 [p &lt; 0.001], and 0.16 [p &lt; 0.001], respectively). Older age and diabetes mellitus at the time of KT were risk factors for incident all-cause dementia and AD in KT recipients. This is the first study to show a beneficial impact of KT on incident dementia compared to dialysis dependency.

Impact of kidney transplantation on serum bone mineral levels and anemia – a cohort study on Egyptian children

Impact of kidney transplantation on serum bone mineral levels and anemia – a cohort study on Egyptian children

Recurrent Urinary Tract Infection in Living Donor Renal Transplant Recipients and the Role of Behavioral Education Program in Management: A Single-Center Experience

Urinary tract infections (UTIs) are the most prevalent type of kidney transplant (KT) recipients. We aimed to investigate the incidence, causes, and clinical impact of early recurrent UTI post-living donor KT and to examine the role of behavioral education program in management. This retrospective cohort chart-review study included all KT recipients with recurrent UTI necessitating hospital admission between September 2017 and August 2021. All patients with recurrent UTI were subjected to behavioral education for a month. UTI was found in 14 of 145 patients (9.6%), with recurrent UTI in 11 (7.6%). A total of 93% of UTIs occurred during the first 6 months post-transplant and represented 52% of KT readmissions during the same period. A total of 64.3% of patients were older than 50 years. The mean (SD) length of hospital stay was 5 (2.5) days, with an equal incidence in both sexes. The most common bacterial isolates in early recurrent UTI were Escherichia coli in 80.9%. Both Extended-spectrum beta-lactamases and multidrug-resistant organisms (resistance in ≥3 drugs) were seen in 82.4% of isolates. Furthermore, the most effective antibiotic was meropenem, with 86.7% effectiveness. A total of 65% of UTIs were managed with a single antibacterial course. A total of 64.3% of patients were older than 50 years. In patients who developed UTI, the mean (SD) serum creatinine was 1.31 (0.52) mg/dL, with a mean increase in serum creatinine of 0.19 mg/dL on having the episodes; at 1 year post-transplant, serum creatinine declined to 1.23 (0.43) mg/dL. Four patients (36%) had no recurrence of UTI after behavioral education. The multidrug-resistant bacterial isolates account for 82.4% of the UTIs. Therefore, antibiotic prescription should follow the antimicrobial stewardship guidelines. Behavioral education significantly reduced the incidence of recurrent UTI.

Impact of kidney transplant on post-operative morbidity and mortality in patients with pre-operative cardiac dysfunction.

Several studies show an increase in complications, both cardiac and non-cardiac, and a higher mortality in patients with preexisting cardiac disease when they undergo elective surgery. Due to the high incidence of cardiac dysfunction in patients with concomitant chronic kidney disease, we wanted to determine if the same negative impact is demonstrated in patients undergoing kidney transplantation. A retrospective analysis was done on 582 patients who underwent kidney transplant from a single transplant center between 2014 and 2019. Participants for this study were divided into two groups based on cardiac ejection fraction: normal EF (≥40%) (n=540) and low EF (<40%) (n=33); exclusion criteria included patients undergoing multi-organ transplants (n=9). Characteristics and outcomes of patients were compared before and after transplant using chi-square tests for categorical measures, and either Kruskal-Wallis or paired Student's t tests for continuous measures. Overall survival (OS) between groups was assessed using the Kaplan-Meier test. We compared outcomes between the normal EF and low EF groups using logistic regression in raw data, and propensity score matched sample and inverse-probability-weighting to mitigate selection bias. There was no significant difference in survival between patients in the low EF and normal EF groups (p=.33). Among patients with low EF, mean EF after transplant significantly improved (mean: 55.83% ± 5.75%) compared to mean EF before transplant (38.28% ± 7.35%), (p=<.0001). Of the patients with a low EF before transplant, 1 in 5 had a history of CAD, compared to only 1 in 10 among those patients with a normal EF, p=.0657. Post-transplant complications were comparable between the groups. Patients undergoing kidney transplantation with a low ejection fraction do not demonstrate an increased incidence of morbidity or mortality in the peri- and post-transplant follow-up compared with patients with a normal ejection fraction. Cardiac events post-transplantation is also comparable between the two groups. Of note, patients with a low EF have a significantly improved EF after kidney transplant which is likely a function of improvement in their physiologic state after the kidney transplant.

P8.091: The Impact of Kidney Transplantation on Systolic And Diastolic Blood Pressure and the Number of Blood Pressure Medications in the First-Year Post- Kidney Transplantation

P8.091: The Impact of Kidney Transplantation on Systolic And Diastolic Blood Pressure and the Number of Blood Pressure Medications in the First-Year Post- Kidney Transplantation

Impact of kidney transplantation in obese candidates: a time-dependent propensity score matching study

ABSTRACT Background Although kidney transplantation (KT) is considered the best treatment for end-stage renal disease (ESRD), there are concerns about its benefit in the obese population because of the increased incidence of post-transplant adverse events. We compared patients who underwent KT versus patients awaiting KT on dialysis. Methods We estimated the life expectancy [restricted mean survival time (RMST)] for a 10-year follow-up by matching on time-dependent propensity scores. The primary outcome was time to death. Results In patients with a body mass index (BMI) ≥30 kg/m2 (n = 2155 patients per arm), the RMST was 8.23 years [95% confidence interval (CI) 8.05–8.40] in the KT group versus 8.00 years (95% CI 7.82–8.18) in the awaiting KT group, a difference of 2.71 months (95% CI −0.19–5.63). In patients with a BMI ≥35 kg/m2 (n = 212 patients per arm), we reported no significant difference [8.56 years (95% CI 7.96–9.08) versus 8.66 (95% CI 8.10–9.17)]. Hence we deduced that KT in patients with a BMI between 30 and 35 kg/m2 was beneficial in terms of life expectancy. Conclusion Regarding the organ shortage, KT may be questionable for those with a BMI ≥35 kg/m2. These results do not mean that a BMI ≥35 kg/m2 should be a barrier to KT, but it should be accounted for in allocation systems to better assign grafts and maximize the overall life expectancy of ESRD patients.

The Impact of Kidney Transplantation on the Serum Fatty Acid Profile in Patients with End-Stage Kidney Disease.

Epidemiological data indicate that metabolic disturbances and increased cardiovascular risk in renal transplant patients are a significant and common problem. Therefore, it is important to search for new solutions and, at the same time, counteract the negative effects of currently used therapies. In this study, we examined the effect of kidney transplantation on the serum levels of fatty acids (FAs) in order to assess the role of these compounds in the health of transplant patients. The FA profile was analyzed by gas chromatography-mass spectrometry in the serum of 35 kidney transplant recipients, just before transplantation and 3 months later. The content of total n-3 polyunsaturated FAs (PUFAs) decreased after transplantation (3.06 ± 0.13% vs. 2.66 ± 0.14%; p < 0.05). The total amount of ultra-long-chain FAs containing 26 and more carbon atoms was significantly reduced (0.08 ± 0.009% vs. 0.05 ± 0.007%; p < 0.05). The desaturation index (18:1/18:0) increased after transplantation (3.92 ± 0.11% vs. 4.36 ± 0.18%; p < 0.05). The study showed a significant reduction in n-3 PUFAs in renal transplant recipients 3 months after transplantation, which may contribute to increased cardiovascular risk in this patient population.

Kidney Transplantation and Monoclonal Gammopathy of Undetermined Significance

Plasma cell disorders are one of the most common hematologic malignancies. Monoclonal gammopathy of undetermined significance (MGUS) is defined by a serum monoclonal protein <3 g/dL, bone marrow plasma cell infiltration <10%, and most importantly absence of end-organ damage. The prevalence of MGUS in general population is estimated to be 1%-4% and its frequency increases with age with 3% among people above 50 y of age. The risk of progression to clinically significant plasma cell dyscrasia is estimated to be 1% per year. With aging population and increasing use of transplantation for the management of kidney disease in older adults, MGUS is being identified during the evaluation for kidney transplant candidacy or during the postkidney transplant follow-up. MGUS in patients with end-stage renal disease (ESRD) undergoing evaluation for kidney transplant can pose a complex management dilemma. In this article, we review the current state of knowledge about the prevalence of MGUS in ESRD population and the impact of kidney transplantation on the progression of MGUS to clinically significant plasma cell disorder. We make recommendations for the screening of ESRD patients undergoing kidney transplant evaluation and the management of MGUS after renal transplant.

Impact of kidney transplantation on the risk of retinal vein occlusion in end-stage renal disease

It has been known that retinal vein occlusion (RVO) is associated with chronic kidney disease, especially end-stage renal disease (ESRD). However, little is known about the effect of kidney transplantation (KT) on RVO incidence in ESRD patients. This study aimed to compare the incidence of RVO in KT recipients (n = 10,498), matched ESRD patients (n = 10,498), and healthy controls (HCs, n = 10,498), using a long-term population-based cohort. The incidence of RVO was 2.74, 5.68, and 1.02 per 1000 patient-years, for the KT group, the ESRD group, and the HCs group, respectively. Adjusted hazard ratios for RVO development compared to the HCs group, were 1.53 and 3.21, in the KT group and the ESRD group, respectively. In the KT group, multivariable regression analysis indicated that an age over 50, a Charlson Comorbidity Index score over 4, and a history of desensitization therapy were associated with an increased risk of RVO. In summary, KT recipients have a lower risk for development of RVO than ESRD patients treated with dialysis. However, the risk is still higher compared to healthy people who have normal kidney functions.

Impact of kidney transplantation on functional status

Background and aims Functional capacity (FC) is known to affect morbidity and mortality in kidney transplantation. Despite this important role, little is known about the variables influencing post-transplant FC. Our study aims at identifying these crucial associations. Method Our study included 16,684 renal transplant recipients (RTR). Patients had transplant between 1 September 2018 and 1 September 2019. Mild functional impairment was defined as those with a KPSS score > or = 80; moderate functional impairment was defined as those with a KPSS score between 50 and 70 and severe functional impairment was defined as those with a KPSS score < or =40. The outcome measured was FC at follow-up one-year post-transplant. Abnormal FC at follow-up was defined as those with KPSS score less than 80%. Normal FC at follow-up was defined as those with KPSS score equal or above 80%. Multivariate logistic regression was used to assess with the relationship between patient characteristics and abnormal functional status post-transplant. Results Three groups were identified; those with none-to-mild functional impairment at time of transplant (Group A; n = 8388), those who had moderate impairment at time of transplant (Group B; n = 7694) and those who had severe impairment at time of transplant (Group C; n = 602). Abnormal FC at one-year post transplant was present in 7.69%, 28.89%, 49.49% of patients in group A, B and C, respectively. Glucocorticoid withdrawal was associated with lower risk of developing abnormal FC post-transplant (OR = 0.75, p value = .02, 95% confidence intervals: 0.64 to 0.97), while recipient diabetes was associated with higher risk of abnormal FC (OR = 1.44, p value <.01, 95% confidence intervals: 1.20 to 1.74) in adjusted model. Conclusion Kidney transplantation is associated with substantial improvement in all stages of FC in KTRs. Glucocorticoid withdrawal and diabetes mellitus are potentially modifiable factors of FC and merit further considerations during pre-transplant workup and post-transplant immunosuppressive therapeutic planning. Key messages Kidney transplantation is associated with substantial improvement in all stages of FC in KTRs. Glucocorticoid withdrawal and diabetes mellitus are potentially modifiable factors of FC and merit further considerations during pre-transplant workup and post-transplant immunosuppressive therapeutic planning.

Impact of Kidney Transplantation on Male Sexual Function: Results from a Ten-Year Retrospective Study

BackgroundThe effects of kidney transplantation on male sexual function are controversial. AimTo evaluate the impact of kidney transplantation on erectile and ejaculatory function and to assess a possible correlation between some selected characteristics of patients and their erectile and ejaculatory function after renal transplantation. MethodsAn observational retrospective analysis was conducted on male patients who had undergone kidney transplantation from January 2009 to April 2019. A prospectively maintained database was used to collect all data. Patients were evaluated before kidney transplant and 6 and 12 months after kidney transplant. Male patients undergoing renal transplantation for any cause who were sexually active with a stable partner were included in the study. OutcomesThe main outcome measures included the International Index of Erectile Function (IIEF-15) and the 4-item version of Male Sexual Health Quality–Ejaculation Disorders (MSHQ-EjD Short Form) questionnaires. The first 3 questions of the MSHQ-EjD Short Form were used to assess the ejaculatory function, whereas the fourth question was used to evaluate the ejaculation bother. ResultsA total of 95 patients were eligible in the study. The evaluation of sexual function was available in 56 patients (58.9%). Mean IIEF-15 significantly decreased at 6 months (P < .001) remaining unchanged at 12 months (P = .228). Mean MSHQ-EjD Short Form (1–3) significantly decreased at 6-month follow-up (P < .001) and at 12-month follow-up (P = .024). Mean MSHQ-EjD Short Form (4) was significantly increased compared with the baseline at both 6 and 12 months (P < .05). IIEF-15 was significantly related to the MSHQ-EjD Short Form at 6-month and 12-month follow-up (P < .001). Age, diabetes, hypertension, smoking, pretransplantation testosterone, time for transplantation, baseline IIEF-15, and baseline MSHQ-EjD Short Form (1–3) were significantly associated (P < .05) with both IIEF-15 and the MSHQ-EjD Short Form (1–3) at 6-month and 12-month follow-up after kidney transplantation. Clinical ImplicationsImprovement of knowledge regarding the effects of kidney transplantation on sexual function and about the patient characteristics related to sexual health after transplantation. Strength & LimitationsThis is the first article that analyzes in depth the ejaculatory function in patients who had undergone kidney transplantation assessing ejaculation with a validated questionnaire. The main limitation is the retrospective design of the study. ConclusionKidney transplantation appears to have a negative impact on sexual health, significantly worsening both erectile and ejaculatory functions. Age, diabetes, hypertension, smoking, pretransplantation testosterone levels, time for transplantation, as well as erectile and ejaculatory function before transplant were significantly related to erectile and ejaculatory functions after renal transplantation.Spirito L, Manfredi C, Carrano R, et al. Impact of Kidney Transplantation on Male Sexual Function: Results from a Ten-Year Retrospective Study. J Sex Med 2020;17:2191–2197.

Transitions in frailty state after kidney transplantation

PurposeFrailty is the body’s failure to return to homeostasis after every day or acute stressful events, causing adverse outcomes. To study its dynamics in kidney transplant recipients (KTR), we determined whether the degree of frailty and its domains are affected by kidney transplantation (KT).MethodsBetween 2015 and 2017, 176 KTR were included. Frailty scores were measured using the Groningen Frailty Indicator (GFI), assessed preoperatively and during follow-up. Transitions in frailty state and changes in the individual domains were determined.ResultsMean age (±SD) was 51.8 (± 14.1) years, and 63.1% of KTR were male. Thirty patients were considered frail (GFI ≥ 4) at baseline. After a mean follow-up of 22.8 ± 8.3 months, 34 non-frail patients (19.3%) became frail, 125 patients (71.0%) remained the same, and 17 frail patients (9.7%) became non-frail (GFI < 4). In the domain psychosocial functioning, 28.4% of the patients had an increase in GFI score after follow-up. Patients who scored a point in the domain cognition at baseline had a greater chance of becoming frail (OR 4.38, 95% CI 0.59–32.24).ConclusionIn conclusion, almost one-fifth of non-frail KTR transitioned to a frail state after their transplantation. These results could be used to predict the impact of KT on frailty course and help with implementing prehabilitation for patients at risk.

Impact of kidney transplantation on sleep apnea severity: A prospective polysomnographic study.

Fluid overload has been associated with a high prevalence of sleep apnea (SA) in patients with end-stage kidney disease (ESKD). In this prospective study, we hypothesized that improvement in kidney function and hydration status after kidney transplantation (Tx) may result in an improvement in SA severity. A total of 196 patients on the kidney Tx waiting list were screened for SA using home nocturnal polysomnography (PSG) to measure the apnea-hypopnea index (AHI) and underwent bioimpedance to assess body composition. Of 88 participants (44.9%) with SA (AHI≥15/h), 42 were reassessed 6months post-Tx and were compared with 27 control patients. There was a significant, but small, post-Tx improvement in AHI (from 44.2±24.3 to 34.7±20.9/h, P=.02) that significantly correlated with a reduction in fluid overload (from 1.8±2.0 to 1.2±1.2L, P=.02) and body water (from 54.9% to 51.6%, P=.003). A post-Tx increase in body fat mass (from 26% to 30%, P=.003) possibly blunted the beneficial impact of kidney Tx on SA. All parameters remained unchanged in the control group. In conclusion, SA is a frequent condition in ESKD patients and partially improved by kidney Tx. We suggest that SA should be systematically assessed before and after kidney Tx. ClinicalTrials.gov Identifier: NCT02020642.

Impact of kidney transplantation on sleep apnea severity: a prospective controlled polysomnographic study

Impact of kidney transplantation on sleep apnea severity: a prospective controlled polysomnographic study

Impact of kidney transplantation on aortic stiffness and aortic stiffness index β0

In chronic kidney disease, the enhanced aortic stiffness increases risk of cardiovascular events. Kidney transplantation (KTx) may improve aortic stiffness; however, it is unclear whether the improvement of aortic stiffness is merely the outcome of the reduction of blood pressure (BP) post-KTx. Furthermore, the long-term trajectory of aortic stiffness remains uncertain, as activation of the immune system may have a negative long-term impact on arterial wall property. Using aortic stiffness β0 as a BP-independent stiffness parameter, and a statistical adjustment for BP, we aimed to examine the early vs. late changes in aortic stiffness, and to define the characteristics of patients with favourable and unfavourable long-term trajectories of aortic stiffness. In this longitudinal study, aortic stiffness was assessed before, 3, 6 and 24 months after KTx in 79 individuals. Aortic stiffness was determined by carotid-femoral pulse wave velocity (cf-PWV), and aortic stiffness index β0 was obtained by applying the stiffness parameter β0 theory to cf-PWV based on Bramwell-Hill's equation using a reference pressure. There was an early reduction of β0 3 months after KTx (29.0 ± 2.0 to 25.8 ± 1.2, P = 0.033) followed by a gradual increase at 6 (28.0 ± 1.4, P = 0.005 vs. 3 months) and 24 months (28.3 ± 1.3, P = 0.003 vs. 3 months). A late increase in β0 was associated with higher levels of the interleukin-6 (P = 0.029) even after adjustment for potential cofounders. Using statistical adjustments for BP showed similar results. Reduction of aortic stiffness index β0 3 months after KTx suggests that KTx leads to an early de-stiffening of the intrinsic mechanical properties of aorta. However, this improvement is followed by a later stiffening, which is associated with increased interleukin-6, suggesting that activation of the immune system may be involved in arterial wall remodelling in kidney recipients.

One-Year Impact of Kidney Transplantation on Cardiac Abnormalities and Blood Pressure in Hemodialysis Patients.

Cardiac abnormalities, including left ventricular hypertrophy and systolic dysfunction, are frequently observed among patients with CKD, including kidney transplant recipients; they are closely linked to cardiovascular disease and mortality. Although several studies have been performed for elucidating changes and mechanisms of cardiac abnormalities after kidney transplantation, details remain unclear. This study included 43 consecutive patients who underwent HD and received kidney transplantation between 2008 and 2012 at our institution. All subjects underwent echocardiography before and 1 year after kidney transplantation. One year after kidney transplantation, left ventricular mass index, cardiac chamber sizes, BP, and the number of antihypertensive agents were reduced. Although the percentage of patients with concentric hypertrophy did not change, the percentage of those with eccentric hypertrophy significantly decreased after kidney transplantation. Volume reduction due to the recovery of kidney function may be primarily attributed to the improvement of cardiac abnormalities, including left ventricular hypertrophy.