A comparison of quality of sleep between patients with chronic kidney disease not on hemodialysis and end-stage renal disease on hemodialysis in a developing country

Few studies have compared quality of sleep between pre-dialysis chronic kidney disease (pre-dialysis CKD) patients and end-stage renal disease patients on dialysis (ESRD) and have found inconsistent results. Objective of this study is to compare quality of sleep between patients with pre-dialysis CKD and ESRD in a developing country. This study was conducted in an out-patient department and hemodialysis unit of a tertiary care facility. Patients included had either pre-dialysis CKD or ESRD. Assessment of quality of sleep was done using Pittsburgh sleep quality index (PSQI). A total of 152 patients were included in the study. Out of these patients, 79 (52%) had ESRD and 73 (48%) had pre-dialysis CKD. Median PSQI score was 6 (IQR 3–8.8). Poor sleep quality (PSQI ≥5) was present in 100 (65.8%) patients. Only hemoglobin (β?=??0.39, p?β?=?0.56, p?β?=?0.22, p?r?=??0.34, p value .80) in pre-dialysis CKD patients. Poor sleep quality is common in patients with CKD including hemodialysis patients in a developing country, which is independent of kidney function in non-dialysis patients. There is no difference in quality of sleep between pre-dialysis CKD and ESRD patients.     

Psychological distress and depression in patients with chronic kidney disease

Depressive disorders are 1.5-4 times more prevalent in medically ill patients than in the general population. Mood disorders can be regarded as the final common pathway developing from the interaction among multiple pathophysiological, psychological, and socioeconomic stressors that chronic illness imposes on the individual. Symptoms of clinical depression affect approximately 25% patients on hemodialysis and can be associated with low quality of life and increased mortality. The epidemiology of depressive disorders is less well studied in the renal transplant population. However, depression is a risk factor for poor outcomes, such as graft failure and death after renal transplantation. A high prevalence of severe psychological distress in patients with advanced CKD and its impact on CKD outcomes call for screening and intervention integrated in routine renal care. Preliminary data indicate that some of the selective serotonin reuptake inhibitor agents and time-limited, manualized, structured psychotherapies can be safe and effective for treating depression in this population.     

The periodontal status of pre-dialysis chronic kidney disease and maintenance dialysis patients.

BACKGROUND: Periodontitis contributes to generalized inflammation and development of systemic diseases, including atherosclerosis and cardiovascular disease. Its extent in maintenance haemodialysis (HD) patients is disputable and not known in continuous ambulatory peritoneal dialysis (CAPD) and pre-dialysis chronic kidney disease (CKD) patients. METHODS: One hundred and six patients (35 on HD, mean age, 56 years; 33 on CAPD, mean age 51 years; and 38 pre-dialysis CKD stage 2-5, mean age 51 years) from north-eastern Poland were enrolled. Dialysis subjects were recruited from a cohort of 141 HD and 61 CAPD patients. Two control groups comprised 26 generally healthy individuals with advanced periodontitis requiring specialized treatment, and 30 subjects from general population. Gingival index (GI), papillary bleeding index (PBI), plaque index (PI), loss of clinical attachment level (CAL) and community periodontal index of treatment needs (CPITN) were determined according to WHO recommendations. RESULTS: Average values of the indices in HD, CAPD, pre-dialysis CKD, advanced periodontitis and general population subjects were as follows: GI-1.37, 0.95, 1, 2 and 1; PBI-1.45, 0, 0, 2.20 and 1; PI-2.05, 1.59, 1, 2 and 1; and CAL loss-5.11, 3.47, 2.50, 4.68 and 1.40 mm, respectively. CPITN, analysed separately as community periodontal index and periodontal treatment needs, further indicated a high severity of periodontitis in all renal failure groups as compared with general population subjects. The disease was most advanced in maintenance HD patients-comparable to the full-symptomatic form of periodontitis; then it was successively diminished in CAPD and pre-dialysis CKD subjects. CONCLUSIONS: Periodontal disease is prevalent, severe and under recognized in renal failure patients. Prophylaxis and early dental treatment should be intensified in these subjects, and may be of interdisciplinary importance.     

High prevalence of low bone mineral density in pre-dialysis chronic kidney disease patients: bone histomorphometric analysis

Chronic kidney disease (CKD) leads to reduced bone mineral density (BMD) in pre-dialysis and dialysis patients. A few studies have used dual-energy x-ray absorptiometry (DEXA) to assess BMD in pre-dialysis CKD patients and have shown low BMD to be highly prevalent. Until now there have been no studies reporting the histological features of low BMD in pre-dialysis CKD patients. AIM: To determine the prevalence and histological features of low BMD in pre-dialysis CKD patients. METHOD: Pre-dialysis CKD patients (n = 103, 46 females/57 males), median creatinine clearance of 29 (10 - 78) ml/min/ 1.73 m2, were evaluated using biochemical analysis and DEXA. Bone biopsies were obtained from those with low BMD. RESULTS: Fifty (48.5%) out of the 103 patients had low BMD (LBD group) and 53 (51.5%) had normal BMD (NBD group). The risk for low BMD was increased in those patients with alkaline phosphatase levels above 190 U/l and intact-PTH (iPTH) below 70 pg/ml (p < 0.05). Demographic and biochemical parameters from both groups were comparable, except for lower body mass index (BMI) in LBD subjects (p = 0.04). Women who had been post-menopausal for at least 1 year comprised 65% (13/20) and 50% (13/26) of the LBD and NBD groups, respectively (p = NS). In 40 LBD patients, bone histomorphometry revealed adynamic bone disease (ABD, 52.5%), osteomalacia (OM, 42.5%) and mixed bone disease (MBD, 5%). Trabecular bone volume (BV/TV) was lower in ABD and OM patients. A nearly significant association was found between ABD and iPTH < or = 150 pg/ml (p = 0.056), whereas higher values of iPTH were associated with OM. Total alkaline phosphatase < or = 190 U/l was significantly associated with ABD, whereas higher values were associated with OM. No correlation was observed between BV/TV and BMD. CONCLUSION: Low BMD is frequent in pre-dialysis CKD patients, and low turnover bone disease, manifesting as ABD and OM, was the hallmark of this bone loss.     

Risk factors for high erythropoiesis stimulating agent resistance index in pre-dialysis chronic kidney disease patients,stages 4 and 5

Background/aims  

Anemia is common in patients with chronic kidney disease (CKD). Recently, the erythropoiesis-stimulating agent/hemoglobin level (ESA/Hb) index emerged as a new factor associated with increased morbidity and mortality in this population. In this study, we evaluated the factors that influence the ESA/Hb index in a pre-dialysis CKD population.     

Decreased physical function in pre-dialysis patients with chronic kidney disease

Background

Patients undergoing dialysis experience decreases in physical function; however, few data exist on physical function in pre-dialysis patients with chronic kidney disease (CKD). The primary objective of this study was to clarify physical function in pre-dialysis patients according to CKD stage.

Methods

This was a cross-sectional study of 120 ambulant pre-dialysis CKD stage 2 or higher patients (85 male, 35 female; mean age 66.5 years) who visited St. Marianna University School of Medicine Hospital. Participants were grouped according to CKD stage as follows: stage 2 (n = 17), stage 3 (n = 55), stage 4 (n = 25), and stage 5 (n = 23). Handgrip strength, knee extensor muscle strength, single-leg stance time, and maximum gait speed were used to assess physical function. Clinical laboratory tests were also examined at the same time as physical function measurements.

Results

All indices of physical function decreased according to the progression of CKD. Each physical function index was significantly lower in CKD stage 4 or 5 patients than CKD stage 2 or 3 patients. All physical function indices showed a positive correlation with estimated glomerular filtration rate (eGFR), blood hemoglobin level, and serum albumin level, and a negative correlation with urinary protein levels. In multiple regression analysis, age, female sex, body mass index, eGFR and urinary protein were significantly correlated with indices of physical function.

Conclusion

Physical function in pre-dialysis CKD patients decreased as the disease progressed according to stage. Early intervention in CKD patients might delay the loss of physical function.     

慢性肾脏病非糖尿病非透析患者动脉僵硬度及其相关因素

目的 研究慢性肾脏病(CKD)3~5期非透析非糖尿病患者的动脉僵硬度,并探讨相关影响因素。 方法 采用Complior SP脉搏波速度(PWV)测定仪测定CKD患者颈动脉-股动脉PWV（CFPWV）。用多部位X线平片检测血管钙化情况。常规检测血压、相关血生化指标和全段甲状旁腺素（iPTH）水平。多元逐步回归方法分析影响PWV的因素。30例性别、年龄匹配的健康成人作为对照,检测CFPWV。 结果 入选患者96例,平均年龄（53.7±14.2）岁。CKD3、4、5期患者分别为32例、30例和34例,其CFPWV分别为（11.63±2.39） m/s、（11.70±2.80） m/s、（12.88±2.49） m/s,均高于健康对照（9.70±1.66） m/s（P < 0.05）。多元逐步回归分析结果显示,年龄、平均动脉压、血管钙化和iPTH是CFPWV的独立影响因素。 结论 CKD非糖尿病非透析患者大动脉僵硬度显著增加。年龄、平均动脉压、血管钙化和iPTH是CFPWV的独立影响因素。     

Psychosocial factors in people with chronic kidney disease prior to renal replacement therapy

Increasing evidence implicates psychosocial factors including depression, anxiety, perceived social support and health‐related quality of life in the pathophysiology of various chronic diseases. Research examining the psychosocial aspects of kidney disease has focussed predominantly on depressive disorders in dialysis patients where they are independently associated with increased risk of mortality and poor health‐related quality of life. In contrast, studies examining the influence of psychosocial factors in people with chronic kidney disease (CKD) prior to the initiation of renal replacement therapy are sparse. Limited data indicate that clinical depression and depressive symptoms are common and may independently predict progression to dialysis, hospitalization and death. In contrast, the influence of anxiety disorders, lower perceived social support and impaired health‐related quality of life on the clinical course of CKD have received little attention. Large‐scale prospective cohort studies are needed to clarify the burden and prognostic impact of these factors in this vulnerable population. Given the escalating burden of CKD worldwide examining the role of these potentially modifiable risk factors is crucial. Identifying and implementing targeted interventions in order to prevent or delay the progression of CKD and improve quality of life will be a major challenge.     

Erythropoietin therapy in pre-dialysis patients with chronic renal failure: lack of need for parenteral iron

BACKGROUND: During erythropoietin therapy, scant information exists regarding the optimal target percent saturation of transferrin (TSAT), ferritin and the mode and amount of iron supplementation in pre-dialysis patients with anemia due to chronic kidney disease (CKD). HYPOTHESIS: Pre-dialysis CKD patients may have different needs for iron supplementation than end-stage renal disease subjects during erythropoietin therapy. METHODS: Retrospective analysis of pre-dialysis CKD subjects (n = 31) treated with erythropoietin at our institution. RESULTS: In this population our results showed that target hematocrit (33-36%) was achievable with erythropoietin (mean subcutaneous dose 86 +/- 17 [SD] units/kg/week) without parenteral iron therapy. The hematocrit increased from a mean baseline value of 28.4 +/- 2.7 to 33.6 +/- 3.4% at time 1 (4-9 weeks, p < 0.0001), and to 37.7 +/- 4.5% at time 2 (10-20 weeks, p < 0.0001). The hemoglobin concentration increased from 9 +/- 0.9 g/dl at baseline to 10.7 +/- 1.1 g/dl at time 1 (p < 0.0001) and to 12 +/- 1.5 g/dl at time 2 (p < 0.0001). Subgroup analyses of patients prescribed <200 mg oral elemental iron per day (n = 10), those with TSAT <20% and/or ferritin <100 ng/ml (n = 19), and those prescribed erythropoietin <80 units/kg/week (n = 12), all showed a significant increase in hematocrit and hemoglobin. CONCLUSIONS: Our data show that pre-dialysis CKD subjects respond adequately to erythropoietin at or lower than recommended erythropoietin doses without parenteral iron. This response extends even to subgroups with TSAT and/or ferritin levels deemed to indicate iron deficiency in CKD subjects, and may be due to lack of existence of functional iron deficiency in this group of patients.     

Cognitive outcome following kidney transplantation.

BACKGROUND: While a handful of studies have assessed cognition in kidney transplant (TX) recipients, the neuropsychological presentation of this population is not yet clear. Kidney transplantation typically leads to improvement of metabolic factors associated with chronic kidney disease (CKD). However, comorbid diseases independently linked with cognitive compromise often persist, and for this reason, cognitive difficulties may still be present following transplantation. METHODS: In this cross-sectional study, we assessed cognition in 42 kidney TX recipients, 45 outpatients with pre-dialysis CKD and 49 healthy controls using measures of verbal learning and memory and executive functioning. RESULTS: Findings indicated that TX and CKD patients demonstrated significantly worse verbal learning and memory in comparison to controls. While both CKD and TX patients exhibited significantly worse performance than controls on a response inhibition measure, only CKD patients performed significantly worse on a set-shifting task. CONCLUSIONS: Results suggest that, in comparison to controls, verbal memory and executive functioning skills are worse in both CKD and TX patients. Further research is needed to determine the etiology and extent of cognitive compromise, as well as to assess the clinical implications of these findings.     

Glucose intolerance: is it a risk factor for cardiovascular disease in children with chronic kidney disease?

A total of 66 children and adolescents with chronic kidney disease (CKD) (20 pre-dialysis patients and 46 chronic dialysis patients) were evaluated to address the prevalence of abnormalities in glucose and insulin metabolism and their association with cardiovascular disease. Glucose intolerance was assessed using an oral glucose tolerance test; insulin resistance was estimated by the homeostasis model assessment of insulin resistance (HOMA-IR). Carotid artery intima-media thickness (IMT) and left ventricular hypertrophy (LVH) were examined as early markers of cardiovascular disease. Thirty-four patients (7 pre-dialysis, 27 dialysis) exhibited an abnormal glucose tolerance; however, ten patients (7 pre-dialysis, 3 dialysis) were insulin-resistant. Height-specific standard deviation scores of carotid artery IMT were above normal in three of the pre-dialysis patients (15%) and in 34 of the dialysis patients (74%). LVH was present in seven pre-dialysis (35%) and 34 dialysis patients (74%). In addition, two of the pre-dialysis patients (10%) and 18 of the dialysis patients (39%) had severe LVH. The prevalence of both increased carotid artery IMT and LVH were similar in patients with or without glucose intolerance in both groups, but severe LVH was more prevalent in pre-dialysis patients with glucose intolerance (p = 0.042). The multivariate analyses showed that neither carotid artery IMT nor LVM index was predicted by serum glucose levels or HOMA-IR. In conclusion, children with CKD are at a high risk of glucose intolerance and also have a greater risk of subclinical cardiovascular disease (CVD). However, the presence of glucose intolerance does not appear to be an independent risk factor for increased carotid artery IMT or LVH.     

High plasma phosphate as a risk factor for decline in renal function and mortality in pre-dialysis patients.

BACKGROUND: Hyperphosphataemia is associated with increased mortality in patients with chronic kidney disease (CKD) stage IV or on dialysis. Furthermore, in animal studies, elevated plasma phosphate has been shown to be associated with an accelerated decline in renal function. The aim of this study was to determine the association of plasma phosphate with renal function loss and mortality in CKD stage IV-V pre-dialysis patients with GFR <20 ml/min/1.73 m(2). METHODS: Incident pre-dialysis patients were included between 1999 and 2001 in the multi-centre PREPARE study, and followed until 2003 or death. Rate of decline in renal function for each patient was calculated by linear regression using the Modification of Diet in Renal Disease (MDRD) formula to estimate GFR (eGFR). RESULTS: A total of 448 patients were included [mean (SD) age 60 (15) years, eGFR 13 (5.4) ml/min/1.73 m(2), decline in renal function 0.38 (0.95) ml/min/month]. Phosphate concentration at baseline was 4.71 (1.16) mg/dl, calcium 9.25 (0.77) mg/dl and calcium-phosphate product 43.5 (10.9) mg(2)/dl(2). For each mg/dl higher phosphate concentration, the mean (95% CI) decline in renal function increased with 0.154 (0.071-0.237) ml/min/month. After adjustment, this association remained [beta 0.178 (0.082-0.275)]. Seven percent of the patients died. Crude mortality risk was 1.25 (0.85-1.84) per mg/dl increase in phosphate, which increased to 1.62 (1.02-2.59) after adjustment. CONCLUSIONS: High plasma phosphate is an independent risk factor for a more rapid decline in renal function and a higher mortality during the pre-dialysis phase. Plasma phosphate within the normal range is likely of vital importance in pre-dialysis patients.     

Reproducibility of pulse-wave analysis and pulse-wave velocity determination in chronic kidney disease.

BACKGROUND: Indices of central arterial stiffness, derived by use of applanation tonometry, have shown to be strong independent predictors of cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). The objective of this study was to evaluate the intra- and inter-observer and day-to-day reproducibility of pulse-wave analysis (PWA) and pulse-wave velocity (PWV) in pre-dialysis patients with CKD stages 3-5 using applanation tonometry with the SphygmoCor software and hardware. METHODS: Double recordings of the radial pressure waveform and the aortic and brachial PWV were performed under standardized conditions in 19 CKD patients with a mean GFR 25.3 ml/min/1.73 m(2) (range 9.9-42.2) by two trained observers and repeated by one of the observers within a week. RESULTS: The mean inter-observer and day-to-day differences (+/-2 SD) for the augmentation index (AIx) were 0.9 +/- 15.8% and 2.6 +/- 11.2%, for subendocardial viability ratio (SEVR) -0.9 +/- 15.5% and -0.4 +/- 24.7%, for aortic pulse pressure (PP) 1.4 +/- 13.3 mmHg and 0.3 +/- 20.9 mmHg and for aortic PWV 0.3 +/- 3.2 m/s and -0.7 +/- 1.9 m/s, respectively. Intra-observer differences were calculated for each of three sets of double measurements and showed good reproducibility as well. Calculations on sample size needed in a clinical trial showed a limited number of patients needed in a clinical study over time. CONCLUSIONS: PWA and PWV based on applanation tonometry using the SphygmoCor software and hardware are highly reproducible in pre-dialysis patients with CKD with the day-to-day variation being in accordance with the intra- and inter-observer variation. Thus, applanation tonometry using the SphygmoCor system is a simple, non-invasive method to assess central haemodynamics in clinical trials in patients with pre-dialysis CKD with only a limited number of patients needed to detect significant differences.     

Depression in end-stage renal disease hemodialysis patients

Depression has been identified as a complicating comorbid diagnosis in a variety of medical conditions, including end-stage renal disease (ESRD). Despite this, the psychological health of hemodialysis patients is understudied. The purpose of this paper is to review the research and issues involved in the assessment of depression and its sequelae in ESRD. Accurate estimation of the prevalence of depression in the ESRD population has been difficult due to the use of different definitions of depression and varied assessment techniques, the overlap of depressive symptomatology with symptoms of uremia, and the confounding effects of medications. We suggest that depressive affect is a more important construct to study than diagnosis of depression syndromes per se in patients with chronic kidney disease. The Beck Depression Inventory is a reasonable measure of depressive affect in the ESRD population, if a higher than usual cutoff score is used or if its somatic components are omitted. Several pathways link depression and ESRD, and are probably bidirectional. As such, treatment of depressive affect could impact medical as well as psychological outcomes. The need for treatment intervention trials is great. Limited evidence regarding the safety and efficacy of treatment of hemodialysis patients with selective serotonin reuptake inhibitors is available, and cognitive behavioral therapy holds promise as an intervention for depression in this complex medical population.     

Depression in patients with chronic renal disease: where are we going?

Depression is quite prevalent in the end-stage renal disease (ESRD) population, with rates as high as 30% in some dialysis centers. There are fewer data on the epidemiology of depression in patients with earlier stages of chronic kidney disease (CKD), but the disease burden may be just as high. Depression may be associated with worse medical outcomes, including increased mortality. Close attention to screening and treating depression in all patients may be necessary. Several instruments have been used to screen for depression. The most common validated depression screening measure in ESRD patients is the Beck Depression Inventory. There are limited data on the appropriate therapy for depression in CKD patients. Psychotherapy combined with antidepressant medications, such as selective serotonin reuptake inhibitors, may be the optimal form of therapy (always in close consultation with mental health professionals). Adverse effects of antidepressant medications should be considered before prescribing these agents, particularly in patients with reduced glomerular filtration rate. Additional studies are necessary to further evaluate the optimal methods to screen for and treat depression in patients with CKD.     

Promoting functioning and well-being in older CKD patients: review of recent evidence

Osteoporosis, falls, sleep difficulty, cognitive impairment, and depressed mood are major clinical concerns in the geriatric population that are physiologically and psychologically based and are often interrelated. All of these issues have implications for patients’ daily functioning and quality of life (QOL). This review synthesizes recent evidence about these prominent issues in geriatric care and related implications for care of older patients with chronic kidney disease (CKD). Recent evidence about pre-dialysis and dialysis treatment strategies that may help to optimize management of older patients is also considered. Although elderly patients often report better psychosocial adjustment to dialysis than do younger patients, physical functioning and cognitive functioning losses challenge the QOL of many elderly persons. Early management of CKD and attention to anemia, consideration of the benefits of peritoneal dialysis compared with hemodialysis, and inclusion of some form of exercise or regular physical activity in routine care provide key opportunities to enhance the functioning and well-being of older patients.     

Protective effect of regular physical activity on major depressive episodes in patients with early stages of chronic kidney disease

Previous studies have demonstrated an association between physical activity (PA) and depression in diverse population. The purpose of our study is to examine if PA within the recommended level over time is associated with major depressive episode (MDE) in patients with early stages of chronic kidney disease (CKD) in Mainland China. Patients with stages 2–5 CKD not receiving dialysis were enrolled from a nephrology outpatient clinic between May 2014 and February 2016. Based on the patterns of PA over time, all patients were divided into four groups: persistently active, from inactive to active, from active to inactive, and persistently inactive. An MDE was diagnosed by using the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition)-based the Mini International Neuropsychiatric Interview. Among 150 patients, 34 had a current MDE (22.7%) and 116 did not (77.3%). After multivariable adjustment, patients being persistently active had significantly lower odds of having an MDE (odds ratio 0.102, 95% confidence interval, 0.022–0.467, p?=?.003) compared with those who were persistently inactive. Additionally, patients with diabetes mellitus had significantly higher odds of having an MDE (odds ratio 4.287, 95% confidence interval, 1.473–12.483, p?=?.008) compared with those without diabetes mellitus. Our results suggest a protective effect of regular PA on MDE in patients with early stages of CKD in Mainland China.     

Severe hyperparathyroidism in a pre-dialysis chronic kidney disease patient treated with a very low protein diet

The present report describes a case of a 64-year-old pre-dialysis woman with chronic kidney disease (CKD) stage 5, who developed severe hyperparathyroidism. This patient had been on a very low protein diet (VLPD) to delay the progression of CKD and the need for renal replacement therapy (RRT). Her serum calcium levels were high-normal to slightly high during this time. However, her serum intact parathyroid hormone (PTH) levels increased from 400 to 1160?pg/ml rapidly over a period of 3?months. Serum 1,25-(OH)2D levels were low, and ultrasound of the neck showed three markedly enlarged parathyroid glands exceeding 2?cm. Parathyroidectomy was performed, and all glands showed nodular hyperplasia, which indicated severe secondary hyperparathyroidism leading to tertiary. Severe secondary hyperparathyroidism requiring surgical intervention is usually observed in patients with long-term RRT and is relatively rare in the pre-dialysis patient. In this case, extension of the pre-dialysis period by VLPD may have predisposed this patient to develop severe secondary hyperparathyroidism. Thus, careful monitoring of calcium, phosphorus, and PTH may be necessary in patients treated with VLPD even before renal replacement therapy. Furthermore, initiation of dialysis should not be excessively delayed by strict protein restriction dietary therapy.     

Plasma neutrophil gelatinase-associated lipocalin is associated with iron status in anemic patients with pre-dialysis chronic kidney disease

Background

Iron deficiency anemia is common in patients with chronic kidney disease (CKD). Neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of acute kidney injury, is known to be associated with iron metabolism. We investigated whether plasma NGAL level is associated with iron status in pre-dialysis CKD patients with anemia.

Methods

This study included 419 patients who had anemia. The subjects were into categorized into a pre-dialysis group (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m², n = 288) and a non-CKD group (eGFR >60 ml/min/1.73 m², n = 131). The associations between plasma NGAL and iron status (serum ferritin and transferrin saturation [TSAT]), eGFR, albumin, uric acid, total cholesterol, calcium, phosphate, and C-reactive protein (CRP) were assessed.

Results

In non-CKD group, plasma NGAL was not associated with any baseline variables including iron indices (TSAT and serum ferritin). In pre-dialysis group, univariate analysis showed plasma NGAL correlated with eGFR, CRP, TSAT, and serum ferritin. In multivariate analysis, plasma NGAL was independently associated with TSAT. However, serum ferritin lost its association with plasma NGAL. In ROC analysis for identifying iron deficiency, the plasma NGAL (best cut-off value ≤394 ng/ml) was superior to the serum ferritin (suggested cut-off value ≤500 ng/ml) in both sensitivity and specificity.

Conclusions

Plasma NGAL is associated with iron status in anemic patients with pre-dialysis CKD. Further studies are needed to demonstrate the role of plasma NGAL in assessing the iron deficiency and in guiding the iron therapy for pre-dialysis CKD patients.