Increased risk of ischaemic heart disease after kidney donation.

BACKGROUND: Previous reports suggest increased risk of hypertension and cardiovascular mortality after kidney donation. In this study we investigate the occurrence of ischaemic heart disease and cerebrovascular disease, diabetes and cancer in live kidney donors compared with healthy controls eligible for donation. METHODS: Different diagnoses were assessed in 1029 kidney donors and 16 084 controls. The diagnoses at follow-up were self-reported for the controls and registered by a physician for the donors. Stratified logistic regression was used to estimate associations with various disease outcomes, adjusted for gender, age at follow-up, smoking at baseline, body mass index at baseline, systolic blood pressure at baseline and time since the donation. RESULTS: The mean observation time was 11.3 years [standard deviation (SD) 8.1] for donors versus 16.4 years (SD 5.7) for controls. The age at follow-up was 56.1 years (SD 12.4) in donors versus 53.5 years (SD 11.1) in controls and 44% of donors were males versus 39.3% in the controls. At follow-up, 35 (3.5%) of the donors had been diagnosed with ischaemic heart disease versus 267 (1.7%) of the controls. The adjusted odds ratio for ischaemic heart disease was 1.64 (confidence interval 1.10-2.43; P = 0.01) in donors compared with controls. There were no significant differences for the risks of cerebrovascular disease, diabetes or cancer. CONCLUSIONS: During long-term follow-up of kidney donors, we found an increased risk of ischaemic heart disease compared with healthy controls. This information may be important in the follow-up and selection process of living kidney donors.

Insulin secretion and action after pancreas transplantation. A retrospective single-center study.

We explored glucometabolic and renal function after engraftment in all 159 consecutive patients with type 1 diabetes who received pancreas transplantation alone (PTA, n = 80) or simultaneous pancreas and kidney transplantation (SPK, n = 79) in Norway from 2012 until 2017. We report fasting levels of plasma glucose (FPG), C-peptide, eGFR and the homeostasis model assessment of insulin sensitivity (HOMA2(%S)) and beta-cell function (HOMA2(%B)) measured one to three times weekly during the first 8 and at 52 weeks after transplantation. One year after engraftment, in the PTA and SPK groups 52 and 64 were normoglycaemic without exogenous insulin, and two and zero patients were dead. Data at the 52-week visit were missing for 5 and 6 patients in the respective groups. During the first 8 weeks, FPG was lower, C-peptide and HOMA2(%S) were higher and eGFR was lower in the SPK group as compared with the PTA group (all p < .05). 30 out of 157 living patients needed insulin treatment 52 weeks after transplantation, 9/79 in the SPK group and 21/78 in the PTA group (p = .02). In conclusion, patients who underwent SPK showed lower insulin sensitivity, but higher insulin secretory capacity and lower mean blood glucose levels the first 8 weeks after transplantation. Also, a higher proportion of patients in the SPK group were insulin-free after 1 year, compared with the PTA group.

Increased long-term risk for hypertension in kidney donors - a retrospective cohort study.

Kidney donors may be at increased risk of end-stage renal disease and premature mortality. Elevated blood pressure after donation may contribute to the increased risks. In this cohort study, we have assessed long-term risk for the development of hypertension in kidney donors compared to a control group potentially eligible as donors. Follow-up data were obtained from previous living kidney donors. A healthy control group with baseline assessment from similar time periods as the donor nephrectomies was selected. Hypertension was defined as blood pressure >140/90, use of blood pressure medication, or established diagnosis of hypertension. Stratified logistic regression was used to estimate risk of hypertension at follow-up, adjusted for systolic blood pressure at baseline, age at follow-up, time since donation/baseline, gender, smoking at baseline, and BMI at baseline. A total of 368 donors (36%) had hypertension at follow-up, and 241 of these (23%) were using blood pressure medication. In adjusted stratified logistic regression analyses, odds ratio for hypertension was significantly increased (1.25, 95% confidence interval 1.12-1.39, P < 0.001) in donors compared with controls. Kidney donors appear to be at increased long-term risk for hypertension compared with healthy controls. This finding supports regular follow-up of blood pressure in kidney donors.

Genetic markers associated with long-term cardiovascular outcome in kidney transplant recipients.

There is a clear genetic contribution to the risk of cardiovascular diseases, and a composite genetic risk score (GRS) based on 27 single nucleotide polymorphisms (SNPs) was reported to predict risk of cardiovascular events in the general population. We aimed to evaluate this risk score in renal transplant recipients, a population with heightened cardiovascular risk, with a yet unknown genetic contribution. A total of 1640 participants from the ALERT trial (Assessment of Lescol in Renal Transplantation), a study comparing fluvastatin with placebo in stable renal transplant recipients, were genotyped for all SNPs making up the GRS. Risk alleles were weighted by the log of odds ratios reported in genome wide association studies and summed. Associations between GRS and time from study inclusion to first major cardiovascular event (MACE) were analyzed by Cox regression. In analyses adjusted for cardiovascular risk factors, GRS was significantly associated with MACE (hazard ratio [HR] 1.81, P = .006) when comparing genetic high-risk patients (quartile 4) with genetic low-risk participants (quartile 1). A 27-SNP GRS, which predicted cardiovascular events in the nontransplant population, appears to have predictive value also in kidney allograft recipients. Refining the score to better fit the transplant population seems feasible.

Long-term risk for kidney donors with hypertension at donation - a retrospective cohort study.

In the general population, small increases in blood pressure are associated with increased mortality. In kidney donors this association is less certain. We therefore assessed long-term overall and cardiovascular mortality in donors who were hypertensive at the time of donation compared with normotensive donors. Hypertension was defined as blood pressure >140/90 mmHg or use of antihypertensive drugs. Adequate records available in 2131 donors revealed that 140 were hypertensive and 1991 were normotensive. Multivariable regression analyses were performed for overall and cardiovascular mortality. Hypertensive donors were significantly older (mean 57.7 vs. 46.9 years), more were males (44.3% vs. 41.5%), had higher body mass index (26.4 vs. 24.7) and lower estimated glomerular filtration rate (91.8 vs. 101.2 ml/min/1.73 m2 ). After a median observation time of 20.8 years (interquartile range 11) 71 hypertensive donors had died and 26 of the deaths were cardiovascular. Multivariable analysis did not suggest a generalizable association between hypertension and long-term overall mortality [hazard ratio (HR) 1.1, 95% confidence interval (CI) 0.9-1.5, P = 0.34] or cardiovascular mortality (HR 1.1, 95% CI 0.7-1.8, P = 0.55). These data may support the use of older healthy kidney donors with hypertension at donation.

Paricalcitol supplementation during the first year after kidney transplantation does not affect calcification propensity score.

BACKGROUND: Cardiovascular complications are common in kidney transplant patients and calcification propensity of blood, measured as T50, is associated with cardiovascular outcomes. Paricalcitol supplementation affects calcium/phosphate homeostasis and may affect calcification propensity. To assess this hypothesis we measured T50 in kidney transplant recipients participating in a randomized study comparing paricalcitol versus no treatment during the first year after kidney transplantation. METHODS: Stored serum samples from 76 kidney transplant recipients (paricalcitol n = 37, no treatment n = 39) were analyzed. Analyses were performed at inclusion (8 weeks after transplantation) and repeated one year after transplantation. RESULTS: There were no statistically significant differences in T50 between the paricalcitol and placebo groups, neither at baseline (p = 0.56) nor at 1 year (p = 0.61). Also, there were no significant changes in T50 over time in either group or when pooling all data (p <  0.20). In multivariate regression analysis, out of 16 potentially relevant covariates, comprising clinical and biochemical parameters, only plasma PTH and T50 at baseline were significantly correlated to T50 after one year. (p <  0.03 and p < 0.01, respectively). CONCLUSIONS: Calcium propensity measured as T50 score remained unchanged with paricalcitol treatment in kidney transplant recipients, and was not changed over time during the study period of one year. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01694160 , registered 23 September 2012.

Early introduction of oral paricalcitol in renal transplant recipients. An open-label randomized study.

In stable renal transplant recipients with hyperparathyroidism, previous studies have indicated that vitamin D agonist treatment might have anti-proteinuric effects. Animal studies indicate possible anti-fibrotic and anti-inflammatory effects. Early introduction of paricalcitol in de novo renal transplant recipients might reduce proteinuria and prevent progressive allograft fibrosis. We performed a single-center, prospective, randomized, open-label trial investigating effects of paricalcitol 2 µg/day added to standard care. Participants were included 8 weeks after engraftment and followed for 44 weeks. Primary end point was change in spot urine albumin/creatinine ratio. Exploratory microarray analyses of kidney biopsies at study end investigated potential effects on gene expression. Secondary end points included change in glomerular filtration rate (GFR), pulse wave velocity (PWV), and endothelial function measured by peripheral arterial tonometry as reactive hyperemia index (RHI). Seventy-seven de novo transplanted kidney allograft recipients were included, 37 receiving paricalcitol. Paricalcitol treatment lowered PTH levels (P = 0.01) but did not significantly reduce albuminuria (P = 0.76), change vascular parameters (PWV; P = 0.98, RHI; P = 0.33), or influence GFR (P = 0.57). Allograft gene expression was not influenced. To summarize, in newly transplanted renal allograft recipients, paricalcitol reduced PTH and was well tolerated without negatively affecting kidney function. Paricalcitol did not significantly reduce/prevent albuminuria, improve parameters of vascular health, or influence allograft gene expression.

Long-term risks for kidney donors.

Previous studies have suggested that living kidney donors maintain long-term renal function and experience no increase in cardiovascular or all-cause mortality. However, most analyses have included control groups less healthy than the living donor population and have had relatively short follow-up periods. Here we compared long-term renal function and cardiovascular and all-cause mortality in living kidney donors compared with a control group of individuals who would have been eligible for donation. All-cause mortality, cardiovascular mortality, and end-stage renal disease (ESRD) was identified in 1901 individuals who donated a kidney during 1963 through 2007 with a median follow-up of 15.1 years. A control group of 32,621 potentially eligible kidney donors was selected, with a median follow-up of 24.9 years. Hazard ratio for all-cause death was significantly increased to 1.30 (95% confidence interval 1.11-1.52) for donors compared with controls. There was a significant corresponding increase in cardiovascular death to 1.40 (1.03-1.91), while the risk of ESRD was greatly and significantly increased to 11.38 (4.37-29.6). The overall incidence of ESRD among donors was 302 cases per million and might have been influenced by hereditary factors. Immunological renal disease was the cause of ESRD in the donors. Thus, kidney donors are at increased long-term risk for ESRD, cardiovascular, and all-cause mortality compared with a control group of non-donors who would have been eligible for donation.

Neopterin is associated with cardiovascular events and all-cause mortality in renal transplant patients.

BACKGROUND: Inflammatory markers show significant associations with cardiovascular events and all-cause mortality after kidney transplantation. Neopterin, reflecting interferon-γ-release, may better reflect the proinflammatory state of recipients than less specific markers. METHODS: Kidney transplant recipients in the Assessment of LEscol in Renal Transplant (ALERT) trial were examined and investigated for an association between serum neopterin and subsequent clinical events: graft loss, major cardiovascular events (MACE) and all-cause mortality. RESULTS: After adjustment for established and emerging risk factors neopterin expressed as neopterin-to-creatinine ratio was significantly associated with MACE (p = 0.009) and all-cause mortality (p = 0.002). Endpoints were more frequent with increasing quartiles of neopterin-to-creatinine ratio. The incidence rates of MACE and all-cause mortality were significantly increased in the upper quartiles compared with the first. CONCLUSIONS: This long-term prospective analysis in stable kidney allograft recipients suggests that neopterin is associated with long-term risk of cardiovascular events and all-cause mortality, but not renal outcomes.

Uric acid and clinical correlates of endothelial function in kidney transplant recipients.

UNLABELLED: Uric acid is associated with increased mortality in kidney transplant recipients (KTRs), but it is uncertain if this involves endothelial dysfunction. We hypothesized, first, that there was an association between uric acid and endothelial function, and second, that there were associations between endothelial function and cardiac and mortality risk scores. METHODS: One hundred and fifty-two patients were examined 10 wk after kidney transplantation by two measures of endothelial function, the brachial artery flow-mediated dilatation (FMD) expressed as percent dilatation (FMD%), and fingertip peripheral arterial tone (PAT) expressed as log-reactive hyperemia index (LnRHI). Risk scores were calculated from a recently validated formula. Other clinical correlates of endothelial function were described in stepwise linear regression models. RESULTS: Uric acid was associated negatively with FMD% in an age- and gender-adjusted model, while not in the multivariable model. No association was shown between uric acid and LnRHI. FMD% was associated negatively with risk scores in both crude and age- and gender-adjusted models (p < 0.01). LnRHI was associated negatively with risk scores in the latter model only (p < 0.05). CONCLUSIONS: Uric acid was neither associated with FMD% nor LnRHI in KTRs. There were significant associations between endothelial function indices and cardiac and mortality risk scores.

Trabecular Bone Score Improves Early After Successful Kidney Transplantation Irrespective of Antiresorptive Therapy and Changes in Bone Mineral Density.

Background: Trabecular bone score (TBS) is a new tool to assess trabecular bone microarchitecture based on standard dual-energy x-ray absorptiometry (DXA) of lumbar spine images. TBS may be important to assess bone quality and fracture susceptibility in kidney transplant recipients (KTRs). This study aimed to investigate the effect of different bone therapies on TBS in KTRs. Methods: We reanalyzed DXA scans to assess TBS in 121 de novo KTRs at baseline, 10 wk, and 1 y. This cohort, between 2007 and 2009, participated in a randomized, placebo-controlled trial evaluating the effect of ibandronate versus placebo in addition to vitamin D and calcium. Results: Although bone mineral density (BMD) Z scores showed a subtle decrease in the first weeks, TBS Z scores increased from baseline to 10 wk for both treatment groups, followed by a slight decline at 12 mo. When comparing treatment groups and adjusting for baseline TBS, there were no differences found in TBS at 12 mo (P = 0.419). Correlation between TBS and BMD at baseline was weak (Spearman's ρ = 0.234, P = 0.010), and change in TBS was not correlated with changes in lumbar spine BMD in either of the groups (ρ = 0.003, P = 0.973). Conclusions: Treatment with ibandronate or vitamin D and calcium did not affect bone quality as measured by TBS in de novo KTRs, but TBS increased early, irrespective of intervention. Changes in TBS and BMD during the study period were not correlated, indicating that these measurements reflect different aspects of bone integrity. TBS may complement BMD assessment in identifying KTRs with a high fracture risk.

Health-related quality of life in Norwegian adults with Fabry disease: Disease severity, pain, fatigue and psychological distress.

Health-related quality of life (HRQOL) is reduced in Fabry disease (FD) and associated with clinical disease manifestations, but few have used Fabry-specific severity scores to study how disease burden interferes with quality of life. We investigated how the Fabry DS3, consisting of four somatic domains and one patient-reported item, associates with HRQOL, while also evaluating fatigue, pain and psychological distress as possible predictors. Thirty-six adults with FD completed the Short-form Health Survey (SF-36), the hospital anxiety and depression scale (HADS), the brief pain inventory (BPI) and reported fatigue on a visual analog scale. Clinical data were collected from the last multidisciplinary hospital visit. Using correlation and hierarchical linear regression analyses, we examined associations between demographic, clinical and self-reported predictors and the SF-36 physical (PCS) and mental (MCS) component summary scores. Males scored lower than the general population in all SF-36 domains (P < .05). General health and social functioning were reduced in females. Before including self-reported symptom scores, DS3 showed associations with PCS (P = .009). Our fully adjusted model explained 66% of the variation in PCS, where education (P = .040) and fatigue (P = .002) retained significance. With HADS depression score (P = .001) as the sole significant factor, our regression model explained 56% of the variation in MCS. The DS3 score has implications for HRQOL in FD. Low education and fatigue represent major barriers to physical well-being, while depression strongly influences mental quality of life. Fatigue should be recognized as an important endpoint in future FD trials. Increased efforts to diagnose and treat affective disorders are warranted.

The impact of demographic and clinical characteristics on the trajectories of health-related quality of life among patients with Fabry disease.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder characterized by multiorgan dysfunction. Since individuals with FD usually experience progressive clinical disease manifestations, their health-related quality of life (HRQOL) is expected to change over time. However, there is limited longitudinal research examining HRQOL outcomes in individuals with FD. We aimed to: assess longitudinal outcomes in HRQOL in adults with FD; examine the physical- and mental HRQOL trajectories at the initial registration (baseline), 3-5 year, and 7-13 year follow-ups; and evaluate the possible associations of age, sex and medical complications with the physical- and mental HRQOL trajectories. METHODS: Forty-three individuals with FD (53% female) who were aged 18 to 81 years at baseline attended clinical follow-up visits between 2006 and 2020. Medical records were extracted retrospectively. Demographics and the 36-item Short-Form Health Survey (SF-36) were recorded at scheduled visits, except for the last data collection which was prospectively obtained in 2020. The physical (PCS) and mental (MCS) composite scores (SF-36) were chosen as outcome measures. RESULTS: The eight SF-36 domain scores were stable over a span of 13 years, and only physical- and social functioning domains worsened clinically over this follow-up period. Mean baseline SF-36 domain scores were all significantly lower (decreased HRQOL) in the FD sample compared with Norwegian population norms. Two hierarchical linear models were run to examine whether demographics and medical complications (measured at the last clinical visit) predicted physical and mental HRQOL trajectories. Age above 47 years (p < 0.001), male sex (p = 0.027), small fibre neuropathy (p < 0.001), renal dysfunction (p < 0.001), and cerebrovascular events (p = 0.003) were associated with lower HRQOL over time. No significant interactions were found between the time of follow up and the abovementioned predictors of HRQOL. CONCLUSIONS: Overall HRQOL trajectories remained stable between baseline, 3-5 year, and 7-13 year follow-ups, with the majority of individuals reporting decreased physical and mental HRQOL. Medical complications in combination with older age and male sex are important predictors of lower HRQOL in FD. Awareness of this relationship is valuable both for health care providers and for patients. The findings provide indicators that can guide treatment decisions to improve physical and mental HRQOL outcomes.

Exploring the potential effect of paricalcitol on markers of inflammation in de novo renal transplant recipients.

Following a successful renal transplantation circulating markers of inflammation may remain elevated, and systemic inflammation is associated with worse clinical outcome in renal transplant recipients (RTRs). Vitamin D-receptor (VDR) activation is postulated to modulate inflammation and endothelial function. We aimed to explore if a synthetic vitamin D, paricalcitol, could influence systemic inflammation and immune activation in RTRs. Newly transplanted RTRs were included in an open-label randomized controlled trial on the effect of paricalcitol on top of standard care over the first post-transplant year. Fourteen pre-defined circulating biomarkers reflecting leukocyte activation, endothelial activation, fibrosis and general inflammatory burden were analyzed in 74 RTRs at 8 weeks (baseline) and 1 year post-engraftment. Mean changes in plasma biomarker concentrations were compared by t-test. The expression of genes coding for the same biomarkers were investigated in 1-year surveillance graft biopsies (n = 60). In patients treated with paricalcitol circulating osteoprotegerin levels increased by 0.19 ng/ml, compared with a 0.05 ng/ml increase in controls (p = 0.030). In graft tissue, a 21% higher median gene expression level of TNFRSF11B coding for osteoprotegerin was found in paricalcitol-treated patients compared with controls (p = 0.026). Paricalcitol treatment did not significantly affect the blood- or tissue levels of any other investigated inflammatory marker. In RTRs, paricalcitol treatment might increase both circulating and tissue levels of osteoprotegerin, a modulator of calcification, but potential anti-inflammatory treatment effects in RTRs are likely very modest. [NCT01694160 (2012/107D)]; [www.clinicaltrials.gov].

Cesarean delivery and subsequent pregnancies.

OBJECTIVE: To assess possible effects of a cesarean delivery on outcome in subsequent pregnancies. METHODS: Using an historical cohort design, we analyzed 637,497 first and second births among women with two or more single births and 242,812 first, second, and third births among women with three or more single births registered in the population-based Medical Birth Registry of Norway between 1967 and 2003. RESULTS: Compared with a vaginal delivery at first birth, a cesarean delivery at first birth was followed, in a second pregnancy, by increased risks of preeclampsia (odds ratio [OR] 2.9 and corresponding 95% confidence interval [CI] 2.8-3.1), small for gestational age (OR 1.5; CI 1.4-1.5), placenta previa (OR 1.5; CI 1.3-1.8, placenta accreta (OR 1.9; CI 1.3-2.8), placental abruption (OR 2.0; CI 1.8-2.2), and uterine rupture (OR 37.4; CI 24.9-56.2). After excluding women with the actual complication at first birth, the corresponding ORs were, in general, lower: 1.7 (CI 1.6-1.8), 1.3 (CI 1.3-1.4), 1.4 (CI 1.2-1.7), 1.9 (CI 1.3-2.8), 1.7 (CI 1.6-1.9), and 37.2 (CI 24.7-55.9), respectively. Corresponding reduction in numbers of cesarean deliveries needed to prevent one case were 114, 56, 1,140, 3,706, 300, and 461. In third births, ORs after repeat cesarean delivery were similar to or lower than the ORs after one cesarean delivery; also here, the exclusion of women with the actual outcome in any of their previous pregnancies tended to reduce the ORs. CONCLUSION: Cesarean delivery was associated with an increased risk of complications in a subsequent pregnancy, but excess risks were reduced after excluding women with the actual complication in any of their previous births. To obtain less biased effects of cesarean delivery on subsequent pregnancies, it is important to account for obstetric history. LEVEL OF EVIDENCE: II.

Association Between Pretransplant Cancer and Survival in Kidney Transplant Recipients.

BACKGROUND: Kidney transplantation in recipients with a previous malignancy is often deferred 2 to 5 years after cancer treatment due to fear of cancer recurrence. In Norway, the required waiting period has been 1 year. METHODS: We compared patient and graft survival of recipients with pretransplant cancer to the outcomes of matched recipients without such cancer (comparators) using Cox regression. RESULTS: From 1963 to 2010, 377 (6.4%) of 5867 recipients had a pretransplant cancer. During a median follow-up of 6.8 years, 256 recipients died, 35 (13.7%) from recurrent cancer and 27 (10.5%) from de novo cancer. Uncensored and death-censored graft loss occurred in 263 and 46 recipients, respectively. All-cause mortality was similar as in comparators (hazard ratio [HR], 1.06; 95% confidence interval [CI], 0.93-1.20]; P = 0.40), death-censored graft loss was lower (HR, 0.63; 95% CI, 0.47-0.84; P = 0.002), and uncensored graft loss was similar (HR, 0.99; 95% CI, 0.87-1.12; P = 0.87). Cancer mortality was higher than in comparators (HR, 1.97; 95% CI, 1.51-2.56; P < 0.001), particularly during the first 5 years of follow-up (HR, 3.44; 95% CI, 2.36-5.03; P < 0.01). Waiting period was not associated with recurrent cancer mortality or all-cause mortality (both P > 0.45). Results were similar within cancer subgroups, with most data in patients with a history of kidney cancer, prostate cancer, urothelial cancer, and skin squamous cell carcinoma. CONCLUSIONS: Kidney transplant recipients with a pretransplant cancer had a similar overall patient and graft survival as recipients without such cancer. Cancer mortality was increased, particularly during the first 5 years after transplantation. A short waiting period was not associated with mortality.

Increased risk of all-cause mortality and renal graft loss in stable renal transplant recipients with hyperparathyroidism.

BACKGROUND: Hyperparathyroidism is reported in 10% to 66% of renal transplant recipients (RTR). The influence of persisting hyperparathyroidism on long-term clinical outcomes in RTR has not been examined in a large prospective study. METHODS: We investigated the association between baseline parathyroid hormone (PTH) levels and major cardiovascular events, renal graft loss, and all-cause mortality by Cox Proportional Hazard survival analyses in 1840 stable RTR derived from the Assessment of LEscol in Renal Transplantation trial. Patients were recruited in a mean of 5.1 years after transplantation, and follow-up time was 6 to 7 years. RESULTS: Significant associations between PTH and all 3 outcomes were found in univariate analyses. When adjusting for a range of plausible confounders, including measures of renal function and serum mineral levels, PTH remained significantly associated with all-cause mortality (4% increased risk per 10 units; P=0.004), and with graft loss (6% increased risk per 10 units; P<0.001), but not with major cardiovascular events. Parathyroid hormone above the upper limit of normal (65 pg/mL) indicated a 46% (P=0.006) higher risk of death and an 85% higher risk of graft loss (P<0.001) compared with low/normal values. CONCLUSIONS: Hyperparathyroidism is an independent, potentially remediable, risk factor for renal graft loss and all-cause mortality in RTR.

Homoarginine and Clinical Outcomes in Renal Transplant Recipients: Results From the Assessment of Lescol in Renal Transplantation Study.

BACKGROUND: Despite improvements in kidney transplantation, complications, including cardiovascular morbidity and graft loss, contribute to reduced graft and patient survival. The amino acid homoarginine exerts a variety of beneficial effects that may be relevant for cardiovascular and graft outcomes, which is investigated in the present study. METHODS: Homoarginine was measured in 829 renal transplant recipients participating in the placebo group of the Assessment of Lescol in Renal Transplantation study. Mean follow-up was 6.7 years. By Cox regression analyses, we determined hazard ratios (HRs) to reach prespecified, adjudicated endpoints according to baseline homoarginine levels: major adverse cardiovascular events (n = 103), cerebrovascular events (n = 53), graft failure or doubling of serum creatinine (n = 140), noncardiovascular mortality (n = 51), and all-cause mortality (n = 107). RESULTS: Patients mean age was 50 ± 11 years, homoarginine concentration was 1.96 ± 0.76 µmol/L, and 65% were men. Patients in the lowest homoarginine quartile (<1.40 µmol/L) had an adjusted 2.6-fold higher risk of cerebrovascular events compared to those in the highest quartile (>2.34 µmol/L) (HR, 2.56; 95% confidence interval [95% CI], 1.13-5.82). Similarly, the renal endpoint occurred at a significantly increased rate in the lowest homoarginine quartile (HR, 2.34; 95% CI, 1.36-4.02). For noncardiovascular and all-cause mortality, there was also increased risk associated with the lowest levels of homoarginine, with HRs of 4.34 (95% CI, 1.63-10.69) and 2.50 (95% CI, 1.38-4.55), respectively. CONCLUSIONS: Low homoarginine is strongly associated with cerebrovascular events, graft loss and progression of kidney failure and mortality in renal transplant recipients. Whether interventions with homoarginine supplementation improve clinical outcomes requires further evaluation.

Aortic Stiffness in a Mortality Risk Calculator for Kidney Transplant Recipients.

BACKGROUND: The association between aortic stiffness and all-cause mortality in kidney transplant recipients (KTRs) is uncertain, and aortic stiffness has not yet been incorporated into risk prediction tools. METHODS: During 2007 to 2012, we measured carotid-femoral pulse wave velocity (PWV; SphygmoCor apparatus) 8 weeks after transplantation. The association between PWV and mortality was assessed in a Cox regression analysis adjusting for seven risk factors from a previously validated model. Internal validation was performed by bootstrap resampling, and discrimination and overfitting evaluated by Harrell's C and the calibration slope. RESULTS: Of 1497 KTRs, 1040 (69%) had a valid PWV measurement. During a median follow-up of 4.2 years, 82 patients died. The association between PWV and mortality showed a ceiling effect, and PWV was truncated at 12 m/sec. Each 1 m/sec increase in PWV, up to 12 m/sec, was associated with mortality, hazard ratio (HR) 1.36 (95% CI, 1.14-1.62; P = 0.001). An interquartile range increase (3.8 m/sec) tripled the hazard of mortality, HR, 3.21 (95% CI, 1.63-6.31), similar to the effect of being approximately 20 years older (interquartile range increase (21.6 years); HR, 3.06 [95% CI, 1.87-5.29]). The PWV improved model discrimination with an increase in Harrell's C from 0.76 to 0.78; C difference, 0.024 (95% CI, 0.005-0.043; P = 0.01). Overfitting was moderate with a calibration slope of 0.89, and the final model was adjusted accordingly. A spreadsheet version is presented to estimate expected 5-year survival. CONCLUSIONS: The PWV is a strong risk factor for mortality in KTRs.

Symmetric dimethylarginine as predictor of graft loss and all-cause mortality in renal transplant recipients.

BACKGROUND: Elevated symmetric dimethylarginine (SDMA) has been shown to predict cardiovascular events and all cause mortality in diverse populations. The potential role of SDMA as a risk marker in renal transplant recipients (RTR) has not been investigated. METHODS: We analyzed SDMA in the placebo arm of the Assessment of Lescol in Renal Transplantation study, a randomized controlled trial of fluvastatin in RTR. Mean follow-up was 5.1 years. Patients were grouped into quartiles based on SDMA levels at study inclusion. Relationships between SDMA and traditional risk factors for graft function and all-cause mortality were analyzed in 925 RTR using univariate and multivariate survival analyses. RESULTS: In univariate analysis, SDMA was significantly associated with renal graft loss, all-cause death, and major cardiovascular events. After adjustment for established risk factors including estimated glomerular filtration rate, an elevated SDMA-level (4th quartile, >1.38 µmol/L) was associated with renal graft loss; hazard ratio (HR), 5.51; 95% confidence interval (CI), 1.95-15.57; P=0.001, compared to the 1st quartile. Similarly, SDMA in the 4th quartile was independently associated with all-cause mortality (HR, 4.56; 95% CI, 2.15-9.71; P<0.001), and there was a strong borderline significant trend for an association with cardiovascular mortality (HR, 2.86; 95% CI, 0.99-8.21; P=0.051). CONCLUSION: In stable RTR, an elevated SDMA level is independently associated with increased risk of all-cause mortality and renal graft loss.