Association of symptoms of insomnia and sleep parameters among kidney transplant recipients.

OBJECTIVE: Insomnia complaints are frequent among kidney transplant (kTx) recipients and are associated with fatigue, depression, lower quality of life and increased morbidity. However, it is not known if subjective insomnia symptoms are associated with objective parameters of sleep architecture. Thus, we analyze the association between sleep macrostructure and EEG activity versus insomnia symptoms among kTx recipients. METHODS: Participants (n1=100) were selected from prevalent adult transplant recipients (n0=1214) followed at a single institution. Insomnia symptoms were assessed by the Athens Insomnia Scale (AIS) and standard overnight polysomnography was performed. In a subgroup of patients (n2=56) sleep microstructure was also analyzed with power spectral analysis. RESULTS: In univariable analysis AIS score was not associated with sleep macrostructure parameters (sleep latency, total sleep time, slow wave sleep, wake after sleep onset), nor with NREM and REM beta or delta activity in sleep microstructure. In multivariable analysis after controlling for covariables AIS score was independently associated with the proportion of slow wave sleep (ß=0.263; CI: 0.026-0.500) and REM beta activity (ß=0.323; CI=0.041-0.606) (p<0.05 for both associations). CONCLUSIONS: Among kTx recipients the severity of insomnia symptoms is independently associated with higher proportion of slow wave sleep and increased beta activity during REM sleep but not with other parameters sleep architecture. The results suggest a potential compensatory sleep protective mechanism and a sign of REM sleep instability associated with insomnia symptoms among this population.

Association Between Serum Leptin Level and Mortality in Kidney Transplant Recipients.

OBJECTIVE: Leptin is a hormone made by adipocytes and associated with hypertension, inflammation, and coronary artery disease. Low serum leptin level was associated with higher risk of death in patients with advanced chronic kidney disease. Little is known about the association of serum leptin with outcomes in kidney transplant recipients. DESIGN: Prospective prevalent cohort. SETTING AND SUBJECT: We collected sociodemographic and clinical parameters, medical and transplant history, and laboratory data of 979 prevalent kidney transplant recipients. Associations between serum leptin level and death with a functioning graft, all-cause death, and death-censored graft loss over a 6-year follow-up period were examined in survival models. RESULTS: Serum leptin levels showed moderate negative correlation with eGFR (R = -0.21, P < .001) and positive correlations with BMI (R = 0.48, P < .001) and C-reactive protein (R = 0.20, P < .001). Each 10 ng/mL higher serum leptin level was associated with 7% lower risk of death with functioning graft (hazard ratio [HR] (95% confidence interval [CI]), 0.93 (0.87-0.99)), and this association persisted after adjustment for confounders: HR (95% CI), 0.90 (0.82-0.99). Similar associations were found with all-cause death as outcome. The association between serum leptin level and risk of graft loss was nonlinear, and only low serum leptin level was associated with higher risk of graft loss. CONCLUSIONS: In prevalent kidney transplant recipients, lower serum leptin was an independent predictor of death.

Association between serum resistin level and outcomes in kidney transplant recipients.

Resistin is an adipocytokine that is associated with inflammation, coronary artery disease, and other types of cardiovascular disease among patients with normal kidney function. However, little is known about the association of resistin with outcomes in kidney transplant recipients. We collected socio-demographic and clinical parameters, medical and transplant history, and laboratory data from 988 prevalent kidney transplant recipients enrolled in the Malnutrition-Inflammation in Transplant-Hungary Study (MINIT-HU study). Serum resistin levels were measured at baseline. Associations between serum resistin level and death with a functioning graft over a 6-year follow-up period were examined in unadjusted and adjusted models. The mean±SD age of the study population was 51 ± 13 years, among whom 57% were men and 21% were diabetics. Median serum resistin concentrations were significantly higher in patients who died with a functioning graft as compared to those who did not die during the follow-up period (median [IQR]: 22[15-26] vs. 19[14-22] ng/ml, respectively; P < 0.001). Higher serum resistin level was associated with higher mortality risk in both unadjusted and fully adjusted models: HRs (95% CI): 1.33(1.16-1.54) and 1.21(1.01-1.46), respectively. In prevalent kidney transplant recipients, serum resistin was an independent predictor of death with a functioning graft.

Serum osteoprotegerin is associated with pulse pressure in kidney transplant recipients.

Pulse pressure (PP) reflects increased large artery stiffness, which is caused, in part, by arterial calcification in patients with chronic kidney disease. PP has been shown to predict both cardiovascular and cerebrovascular events in various patient populations, including kidney transplant (KTX) recipients. Osteoprotegerin (OPG) is a marker and regulator of arterial calcification, and it is related to cardiovascular survival in hemodialysis patients. Here we tested the hypothesis that OPG is associated with increased pulse pressure. We cross-sectionally analyzed the association between serum OPG and PP in a prevalent cohort of 969 KTX patients (mean age: 51 +/- --13 years, 57% male, 21% diabetics, mean eGFR 51 +/- 20 ml/min/1.73 m2). Independent associations were tested in a linear regression model adjusted for multiple covariables. PP was positively correlated with serum OPG (rho = 0.284, p < 0.001). Additionally, a positive correlation was seen between PP versus age (r = 0.358, p < 0.001), the Charlson Comorbidity Index (r = 0.232, p < 0.001), serum glucose (r = 0.172, p < 0.001), BMI (r = 0.133, p = 0.001) and serum cholesterol (r = 0.094, p = 0.003). PP was negatively correlated with serum Ca, albumin and eGFR. The association between PP and OPG remained significant after adjusting for multiple potentially relevant covariables (beta = 0.143, p < 0.001). We conclude that serum OPG is independently associated with pulse pressure in kidney transplant recipients.

Circulating Angiopoietin-2 levels predict mortality in kidney transplant recipients: a 4-year prospective case-cohort study.

Angiopoietin 2 (Angpt2) impairs endothelial function by preventing angiopoietin 1 from binding to their common endothelial-specific receptor Tie2. Here, we examined whether circulating Angpt2 predicts outcome in kidney transplant recipients. For this case-cohort study, we selected 130 kidney transplant recipients who had died or returned to dialysis within the first 2 years of follow-up of our cohort study, as well as 130 age- and gender-matched kidney transplant recipients without an event (controls) from a total of 993 kidney transplant recipients. The total of 260 selected patients were followed in median 4 years. Serum Angpt2 at baseline was measured using an in-house immunoluminometric assay. Median Angpt2 concentrations were significantly higher in patients who died [median (interquartile range--IQR) 3.6 (2.8-5.9) ng/ml] as compared to patients who did not die during the study period [2.8 (2.1-4.1) ng/ml; P < 0.001]. Ln (natural log) Angpt2 levels correlated positively with C-reactive protein levels (r = 0.315, P < 0.001) and the Charlson Comorbidity Index (r = 0.188, P = 0.002) and were inversely associated with eGFR (r = -0.301, P < 0.001) hemoglobin (r = -0.269, P < 0.001), and serum albumin concentrations (r = -0.382, P < 0.001). On multivariate analyses, baseline Angpt2 levels independently predicted all-cause mortality (multivariable-adjusted hazard ratio associated with one natural log unit higher Angpt2 level: 1.70 (95% confidence interval: 1.10-2.61)). In our analysis, circulating Angpt2 was an independent predictor of all-cause mortality in stable, prevalent kidney transplant recipients.

Red cell distribution width is associated with mortality in kidney transplant recipients.

BACKGROUND: Red cell distribution width (RDW), a parameter routinely reported as part of the complete blood count, is associated with increased morbidity and mortality risk in different patient populations. No published data are available about the association between RDW and mortality in kidney transplant recipients. METHODS: We collected socio-demographic, clinical parameters, medical and transplant history and laboratory data at baseline in 723 prevalent kidney transplant recipients between June and October 2008 [mean age 51 ± 13 (SD) years, 56 % men, 21 % diabetics]. Associations between baseline RDW values and all-cause mortality over 3 years were examined in unadjusted and adjusted models. RESULTS: Increasing RDW was associated with increased mortality in both unadjusted [(HR(1 % increase) = 1.63; 95 % CI 1.41-1.89) and (HR(>median) = 2.74; 95 % CI 1.68-4.48)] and fully adjusted models [(HR(1 % increase) = 1.60; 95 % CI 1.27-1.89) and (HR(>median) = 1.33; 95 % CI 0.76-2.35)]. In reclassification analyses, RDW improved the predictive value of all-cause mortality prediction models [the net reclassification improvement (NRI) was 0.189; p < 0.001]. CONCLUSIONS: RDW, a cheap and readily available but largely neglected parameter independently, predicts mortality in prevalent kidney transplant recipients and could potentially been used in everyday risk assessment of kidney transplant recipients.

Renal function is independently associated with red cell distribution width in kidney transplant recipients: a potential new auxiliary parameter for the clinical evaluation of patients with chronic kidney disease.

Red cell distribution width (RDW), a measure of heterogeneity in the size of circulating erythrocytes, reportedly predicts mortality. Similarly to RDW, impaired renal function is also associated with inflammation and protein-energy wasting. This study assessed if renal function is associated with RDW independent of relevant confounders in stable kidney transplant recipients. We examined the association between RDW and estimated glomerular filtration rate (eGFR) in a cohort of 723 prevalent kidney transplanted recipients who were not receiving erythropoietin-stimulating agents. Associations were examined in regression models adjusted for age, sex, comorbidity, blood haemoglobin, iron indices, markers of nutritional status and inflammation, markers of bone and mineral metabolism and the use of immune suppressants. Lower eGFR was significantly associated with higher RDW (r = -0·382, P < 0·001). This association remained highly significant even after multivariate adjustments where 10 ml/min decrease in the eGFR was significantly associated with an increase of the RDW values (B10 ml/min decrease  =  0·078; 95% confidence interval: 0·044-0·111). The results were consistent in subgroups of patients with different levels of haemoglobin, chronic kidney disease status and various markers of inflammation and iron status. Lower eGFR is associated with higher RDW, independent of comorbidity, iron deficiency, inflammation and nutritional status in kidney transplant recipients.

Serum adiponectin levels and mortality after kidney transplantation.

BACKGROUND AND OBJECTIVES: Adiponectin (ADPN), an adipose tissue-derived hormone, has protective properties with respect to atherogenesis, inflammation, and energy homeostasis. Its beneficial role has not been consistent in patients with CKD or those undergoing dialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study examined the association of plasma ADPN levels in 987 prevalent kidney transplant recipients (mean age ± SD, 51.0±12.8 years; estimated GFR, 52.8±21.9 ml/min per 1.73 m(2); median time since transplant, 78 months) on all-cause mortality and death-censored graft failure. Patients were enrolled between February and August 2007 and were followed for a median of 51 months (interquartile range, 49-53 months). Using Cox proportional hazard models, the association of log-transformed plasma adiponectin was studied, with and without adjustment for demographic variables, baseline GFR, markers of inflammation, and cardiovascular risk factors. RESULTS: At baseline, patients in the lowest ADPN tertile were significantly more likely to be male; to be smokers; to have a higher baseline GFR, lower systolic BP, and lower HDL cholesterol level; and to have higher body mass index, abdominal circumference, C-reactive protein level, and total cholesterol level. The adjusted hazard ratio for death with elevated plasma ADPN (per natural log) was 1.44, and there was no significant interaction with any relevant cardiovascular risk subgroups (i.e., advanced age; diabetes; or elevated body mass index, waist circumference, C-reactive protein, or Framingham risk score). The hazard for death-censored graft failure was nonsignificant at 1.03. CONCLUSION: Elevated ADPN levels are associated with higher risk for death but not allograft failure in prevalent kidney transplant recipients.

Neuropsychological performance in a sample of 13-25 year olds with a history of non-psychotic major depressive disorder.

BACKGROUND: There is evidence for neuropsychological dysfunction in depression among adult and elderly participants but little research has been conducted on the neuropsychological functioning of youth with depression. The aim of the present study was to investigate the neuropsychological functioning of outpatient young participants with depression. METHODS: Computerised neuropsychological tests requiring executive functioning, working memory, attention, verbal memory and learning, planning, and visuospatial skills were carried out in a sample of 13-25year-olds with a lifetime history of non-psychotic major depression (n=32) and in healthy age balanced controls (n=65). Psychiatric diagnoses were ascertained using the MINI International Neuropsychiatric Interview. RESULTS: Participants with current or previous major depressive disorder demonstrated impairments in executive function tasks requiring conceptual skills and set-shifting, attention and working memory. However, planning skills were found to be largely intact. Positive affect was associated to better attention, working memory and verbal learning in depressed participants, independently from gender and education. LIMITATIONS: The results may be affected by the small sample size and heterogeneity of the sample. CONCLUSION: The findings from this study indicate, and are one of the first to identify, that young subjects aged between 13 and 25, with a lifetime history of depression, have impaired executive and working memory functioning.

Quality of life and protein-energy wasting in kidney transplant recipients.

PURPOSE: Chronic kidney disease has profound effects on the health-related quality of life (HRQoL) of patients, with serious physiological, psychological and socio-economic implications. The co-occurrence of protein-energy wasting and inflammation in end-stage renal disease patients is associated with worse HRQoL and increased mortality. We designed this study to examine the relationship between nutritional and inflammatory status and HRQoL in kidney transplant recipients. METHODS: Data from 100 randomly selected kidney transplant patients were analyzed in a cross-sectional survey. Socio-demographic parameters, laboratory results, transplantation-related data, comorbidities, medication and malnutrition-inflammation score (MIS) (Kalantar Score) were tabulated at baseline. Patients completed the Kidney Disease Quality of Life-SF (KDQoL-SF™) self-administered questionnaire. RESULTS: Mean age was 51 ± 13 years, median (interquartile range, IQR) time since transplantation 66 (83) months, 57% were men, and 19% had diabetes. The median (IQR) MIS was 3 (3). The MIS significantly and negatively correlated with almost all HRQoL domains analyzed, and this association remained significant in multivariate linear regression analysis for the log-transformed scores on energy/fatigue (ß = -0.059 P < 0.001), bodily pain (ß = -0.056 P = 0.004), physical functioning (ß = -0.029, P = 0.022) and symptoms/problems (ß = -0.023 P = 0.005) domains after statistical correction for age, gender, eGFR, dialysis vintage, Charlson Comorbidity Index and occupational status. Additionally, cubic spline analyses revealed linearly increasing, "dose-response" relationship between almost all domains of KDQoL-SF™ and the MIS. CONCLUSIONS: Malnutrition-inflammation score is independently associated with different dimensions of HRQoL in kidney transplant recipients.

Brain-derived neurotrophic factor gene polymorphisms, neurotransmitter levels, and depressive symptoms in an elderly population.

A large number of studies have examined associations between brain-derived neurotrophic factor (BDNF) gene polymorphisms and depressive symptoms. However, results still remain controversial. Recent studies suggested a significant age and gender effect on the heritability of depression. The potential neurobiological pathways that could possibly mediate this relationship have not been examined so far. Since BDNF is involved in the regulation of neurotransmitter production, a mediating role of neurotransmitters seems plausible. The present study aims to examine the association between three common BDNF single-nucleotid polymorphisms (SNPs; rs7103411, rs7124442, and rs6265) and depressive symptoms in a community-based elderly population taking into account the serum levels of four neurotransmitters, serotonin, dopamine, adrenalin, and noradrenalin, as potential mediating factors. We also examined whether age and gender had a modifying effect on this association. We collected and analyzed the genetic and laboratory data as well as Center for Epidemiologic Studies-Depression scores of 350 community-dwelling elderly individuals (aged 65+ years). We found that the BDNF rs6265 polymorphism was related to the severity of depressive symptoms, and that this association was independent of neurotransmitter levels. Stratified analyses showed that this association was restricted to older individuals (≥74 years) and men. The associations of SNPs rs7103411 or rs7124442 SNP with depressive symptoms were not statistically significant. This study importantly adds to the existing literature by affirming previous assumptions on an age and gender difference in the relation between BDNF genotype and depression. We moreover first-time report a missing mediating role of neurotransmitters in this association.

Roma ethnicity and clinical outcomes in kidney transplant recipients.

BACKGROUND: Racial and ethnic disparities among North American patients with chronic kidney disease have received significant attention. In contrast, little is known about health-related outcomes of patients with end-stage renal disease among the Roma minority, also known as gypsies, compared to Caucasian individuals. We prospectively assessed the association between Roma ethnicity and long-term clinical outcomes in kidney transplant recipients. METHODS: In a prevalent cohort of renal transplant recipients, followed up over a median of 94 months, we prospectively collected socio-demographic, medical (and transplant related) characteristics and laboratory data at baseline from 60 Roma and 1,003 Caucasian patients (mean age 45 (SD = 11) and 49 (SD = 13) years, 33 and 41% women, 18 and 17% with diabetes mellitus, respectively). Survival analyses examined the associations between Roma ethnicity and all-cause mortality and death-censored graft loss or death with functioning renal allograft. RESULTS: During the follow-up period, 341 patients (32%) died. Two-hundred eighty (26%) patients died with a functioning graft and 201 patients (19%) returned to dialysis. After multivariable adjustments, Roma ethnicity was associated with 77% higher risk of all-cause mortality (Hazard Ratio (HR): 1.77; 95% confidence interval (CI): 1.02, 3.07), two times higher risk of mortality with functioning graft (2.04 [1.17-3.55]) and 77% higher risk of graft loss (1.77 [1.01-3.13]), respectively. CONCLUSIONS: Roma ethnicity is independently associated with increased mortality risk and worse graft outcome in kidney transplant recipients. Further studies should identify the factors contributing to worse outcomes among Roma patients.

Lack of association between objectively assessed sleep disorders and inflammatory markers among kidney transplant recipients.

PURPOSE: In patients on dialysis, the results of studies examining the association between sleep disorders and inflammation are controversial. We assessed the association between inflammatory markers and different sleep disorders in a large sample of kidney transplant recipients. METHODS: Cross-sectional study of 100 randomly selected kidney transplant patients who underwent one-night polysomnography ("sleep disorders evaluation in patients after kidney transplantation study") to diagnose obstructive sleep apnea (OSA) and periodic limb movements in sleep (PLMS). Athens Insomnia Scale (AIS) was utilized to assess the prevalence of insomnia. Sociodemographic information and data about medication, comorbidity and laboratory parameters were collected. Levels of inflammatory markers, such as C-reactive protein, serum albumin, white blood cell count, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were measured. RESULTS: The mean age was 51 ± 13 years, 43% were women, and the prevalence of diabetes was 19%. We found no significant difference in the levels of inflammatory markers between patients with versus without OSA and PLMS. Apnea-hypopnea index showed a significant association with white blood cell count (ρ = 0.23), and weak (ρ < |0.15|), non-significant correlation with the other inflammatory markers. PLM index showed weak (ρ < |0.15|), non-significant correlation with all markers of inflammation. The serum IL-6 level was significantly higher in patients with insomnia (AIS ≥ 10) than in non-insomniacs [median (IQR): 3.2(2.6-5.1) vs. 1.7(1.2-2.9) ng/l; P = 0.009]. The levels of other inflammatory markers were similar between insomniacs and non-insomniacs. CONCLUSIONS: We did not find any association between the presence of objectively assessed sleep disorders and inflammatory markers in kidney transplant patients.

Periodic limb movements in sleep are associated with stroke and cardiovascular risk factors in patients with renal failure.

Periodic limb movements in sleep (PLMS) is prevalent among dialysed patients and is associated with increased risk of mortality. Our study aimed to determine the prevalence of this disease in a sample of transplanted and waiting-list haemodialysed patients. One hundred transplanted and 50 waiting-list patients underwent polysomnography. Moderate and severe diseases were defined as periodic limb movements in sleep index (PLMSI) higher than 15 and 25 events h(-1), respectively. The 10-year coronary heart disease risk was estimated for all patients using the Framingham Score. Moreover, the 10-year estimated risk of stroke was calculated according to the modified version of the Framingham Stroke Risk Profile. PLMS was present in 27% of the transplanted and 42% of the waiting-list group (P = 0.094); the proportion of severe disease was twice as high in waiting-list versus transplanted patients (32 versus 16%, P = 0.024). Patients with severe disease had a higher 10-year estimated risk of stroke in the transplanted group [10 (7-17) versus 5 (4-10); P = 0.002] and a higher 10-year coronary heart disease risk in both the transplanted [18 (8-22) versus 7 (4-14); P = 0.002], and the waiting-list groups [11 (5-18) versus 4 (1-9); P = 0.032]. In multivariable linear regression models the PLMSI was associated independently with the Framingham cardiovascular and cerebrovascular scores after adjusting for important covariables. Higher PLMSI is an independent predictor of higher cardiovascular and cerebrovascular risk score in patients with chronic kidney disease. Severe PLMS is less frequent in kidney transplant recipients compared to waiting-list dialysis patients.

Brain-derived neurotrophic factor (BDNF) gene: a gender-specific role in cognitive function during normal cognitive aging of the MEMO-Study?

Cognitive aging processes are underpinned by multiple processes including genetic factors. The brain-derived neurotrophic factor (BDNF) has been suggested to be involved in age-related cognitive decline in otherwise healthy individuals. The gender-specific role of the BDNF gene in cognitive aging remains unclear. The identification of genetic biomarkers might be a useful approach to identify individuals at risk of cognitive decline during healthy aging processes. The aim of this study was to investigate the associations between three single-nucleotide polymorphisms (SNPs) in the BDNF gene and domains of cognitive functioning in normal cognitive aging. The sample, comprising 369 participants (M = 72.7 years, SD = 4.45 years), completed an extensive neuropsychological test battery measuring memory, motor function, and perceptual speed. The relationships between the SNPs rs6265, rs7103411, and rs7124442 and cognitive domains were examined. While significant main effects of BDNF SNPs on cognitive function were found for the association between rs7103411 and memory performance, gender-specific analyses revealed for females significant main effects of rs7103411 for memory and of rs6265 for perceptual speed independent of the APOE*E4 status and education. The finding for the association between rs6265 and perceptual speed in females remained significant after Bonferroni correction for multiple comparisons. None of the analyses showed significant results for males. This study is the first to implicate that the SNPs rs6265 and rs7103411 affect cognitive function in the elderly in a gender-specific way.

Serum erythropoietin level and mortality in kidney transplant recipients.

BACKGROUND AND OBJECTIVES: Posttransplant anemia is frequently reported in kidney transplant recipients and is associated with worsened patient survival. Similar to high erythropoiesis-stimulating agent requirements, resistance to endogenous erythropoietin may be associated with worse clinical outcomes in patients with ESRD. We examined the association between serum erythropoietin levels and mortality among kidney transplant recipients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We collected sociodemographic, clinical, medical, and transplant history and laboratory data at baseline in 886 prevalent kidney transplant recipients (mean age 51 ± 13 [SD] years, 60% men, 21% diabetics). A solid-phase chemiluminescent immunometric assay was used to measure serum erythropoietin. Cox proportional hazards regression was used to model the association between baseline serum erythropoietin levels and all-cause mortality risk. RESULTS: During the median 39-month follow-up, 99 subjects died. The median serum erythropoietin level was 10.85 U/L and hemoglobin was 137 ± 16 g/L. Mortality rates were significantly higher in patients with higher erythropoietin levels (crude mortality rates in the highest to lowest erythropoietin tertiles were 51.7, 35.5, and 24.0 per 1000 patient-years, respectively [P = 0.008]). In unadjusted and also in adjusted Cox models each SD higher serum erythropoietin level significantly predicted all-cause mortality: HR(1SD increase) 1.22 and 1.28, respectively. In adjusted Cox models each SD higher serum erythropoietin/blood hemoglobin ratio also significantly predicted all-cause mortality: HR(1SD increase) 1.32. Serum erythropoietin predicted mortality in all analyzed subgroups. CONCLUSIONS: In this sample of prevalent kidney transplant recipients, higher serum erythropoietin levels were associated with increased mortality.

Health-related quality of life and clinical outcomes in kidney transplant recipients.

BACKGROUND: Health-related quality of life (HRQoL) is an important outcome measure in patients with chronic kidney disease. It also has been shown repeatedly to predict mortality in various patient populations. In a prospective cohort study, we assessed the association between HRQoL and long-term clinical outcome in kidney transplant recipients. STUDY DESIGN: Prospective prevalent cohort study. SETTING & PARTICIPANTS: We collected sociodemographic parameters, medical and transplant history, and laboratory data at baseline from 879 prevalent kidney transplant recipients (mean age, 49 ± 13 [standard deviation] years; 58% men; and 17% with diabetes mellitus). PREDICTOR: We assessed HRQoL using the KDQoL-SF (Kidney Disease Quality of Life Short Form) questionnaire and assessed depressive symptoms using the Center for Epidemiologic Studies-Depression Scale. OUTCOMES: All-cause mortality and death-censored transplant loss or death with functioning transplant. Cox regression models and semiparametric competing-risks regression analyses were used to measure associations between HRQoL scores and outcomes. RESULTS: Most examined HRQoL domains were associated with clinical outcome in unadjusted models. After adjusting for several important confounders, the 36-Item Short Form Health Survey (SF-36) Physical Composite Score and Physical Functioning and General Health Perception subscale scores remained independently associated with clinical outcomes. Every 10-point increase in SF-36 Physical Composite Score and Physical Functioning and General Health Perception scores was associated with 18% (HR, 0.82; 95% CI, 0.71-0.95), 11% (HR, 0.89; 95% CI, 0.84-0.94), and 7% lower risks of mortality (HR, 0.93; 95% CI, 0.88-1.00), respectively. LIMITATIONS: Single-center study. CONCLUSIONS: We showed that the SF-36 Physical Composite Score and Physical Functioning and General Health Perception KDQoL-SF domain scores are associated independently with increased risk of mortality in kidney transplant patients. Regular assessment of HRQoL may be a useful tool to inform health care providers about the prognosis of kidney transplant recipients. Additional studies are needed to assess whether interventions aimed at improving HRQoL would improve clinical outcomes in this patient population.

Association between the Malnutrition-Inflammation Score and depressive symptoms in kidney transplanted patients.

OBJECTIVE: Depressive symptoms and the Malnutrition-Inflammation Complex Syndrome (MICS) are prevalent in patients with chronic kidney disease. The complex relationship between MICS and depression has never been studied in kidney transplanted (Tx) patients. Here we evaluate the association between the Malnutrition-Inflammation Score (MIS) (Kalantar score) and depressive symptoms in Tx patients. METHODS: Cross-sectional data of 973 prevalent Tx patients were analyzed. Sociodemographic and anthropometric characteristics and clinical and laboratory data were collected, and serum levels of inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)] were measured. The Center for Epidemiologic Studies-Depression (CES-D) scale, the MIS and the Charlson Comorbidity Index (CCI) were computed. We used linear regression analysis to examine whether the relationship between MIS and CES-D score is independent from sociodemographic and laboratory parameters. RESULTS: The CES-D score, corrected for age, gender and estimated glomerular filtration rate weakly but significantly correlated with serum IL-6 and the CCI (0.124 and 0.103, respectively; P<.05 for both) and marginally significantly with CRP (0.06; P=.06). We found a moderate correlation between CES-D score and MIS (0.262; P<.001). In a multivariable linear regression model, the MIS was independently associated with the CES-D score (B=0.110; P<.001). CONCLUSIONS: The MIS was significantly associated with depressive symptoms after adjusting for important covariables in patients after renal transplantation.

Association of serum phosphorus level with anemia in kidney transplant recipients.

BACKGROUND: Anemia and mineral and bone disorders (MBD) are both important and common complications in kidney transplant recipients. Studies in patients with chronic kidney disease indicated a possible independent association of higher serum phosphorus with anemia, but similar associations have not been examined in kidney transplant recipients. We hypothesized that higher serum phosphorus is associated with anemia independent of other components of MBD. METHODS: We examined the association of serum phosphorus with hemoglobin level and the prevalence of anemia in a prevalent cohort of 992 kidney transplant recipients in a single outpatient transplant center. Associations were examined in linear and logistic regression models with adjustment for demographic and comorbid conditions for various known risk factors of anemia, including measures of iron deficiency, inflammation, and components of MBD including serum levels of 25(OH) vitamin D, parathyroid hormone, and fibroblast growth factor 23. RESULTS: In multivariable adjusted regression models, a 1 standard deviation (0.8 mg/dL) higher serum phosphorus level was associated with 0.26 g/dL lower blood hemoglobin concentration (95% confidence intervals -0.36 to -0.15, P<0.001) and with an odds ratio for anemia of 1.77 (95% confidence intervals 1.33-2.37, P<0.001). These associations were consistent across the entire spectrum of the physiologic serum phosphorus concentration and were more accentuated in patients with lower estimated glomerular filtration rate. CONCLUSIONS: Higher serum phosphorus is independently associated with anemia in kidney transplant recipients.

Elevated fibroblast growth factor 23 is a risk factor for kidney transplant loss and mortality.

An increased circulating level of fibroblast growth factor 23 (FGF23) is an independent risk factor for mortality, cardiovascular disease, and progression of chronic kidney disease (CKD), but its role in transplant allograft and patient survival is unknown. We tested the hypothesis that increased FGF23 is an independent risk factor for all-cause mortality and allograft loss in a prospective cohort of 984 stable kidney transplant recipients. At enrollment, estimated GFR (eGFR) was 51 ± 21 ml/min per 1.73 m(2) and median C-terminal FGF23 was 28 RU/ml (interquartile range, 20 to 43 RU/ml). Higher FGF23 levels independently associated with increased risk of the composite outcome of all-cause mortality and allograft loss (full model hazard ratio: 1.46 per SD increase in logFGF23, 95% confidence interval: 1.28 to 1.68, P<0.001). The results were similar for each component of the composite outcome and in all sensitivity analyses, including prespecified analyses of patients with baseline eGFR of 30 to 90 ml/min per 1.73 m(2). In contrast, other measures of phosphorus metabolism, including serum phosphate and parathyroid hormone (PTH) levels, did not consistently associate with outcomes. We conclude that a high (or elevated) FGF23 is an independent risk factor for death and allograft loss in kidney transplant recipients.