Chronic kidney disease as a metabolic syndrome with malnutrition--need for strict control of risk factors

Five-Aminolevulinic Acid (5-ALA) Induces Heme Oxygenase-1 and Ameliorates Palmitic Acid-Induced Endoplasmic Reticulum Stress in Renal Tubules

Steatosis, or ectopic lipid deposition, is the fundamental pathophysiology of non-alcoholic steatohepatitis and chronic kidney disease. Steatosis in the renal tubule causes endoplasmic reticulum (ER) stress, leading to kidney injury. Thus, ER stress could be a therapeutic target in steatonephropathy. Five-aminolevulinic acid (5-ALA) is a natural product that induces heme oxygenase (HO)-1, which acts as an antioxidant. This study aimed to investigate the therapeutic potential of 5-ALA in lipotoxicity-induced ER stress in human primary renal proximal tubule epithelial cells. Cells were stimulated with palmitic acid (PA) to induce ER stress. Cellular apoptotic signals and expression of genes involved in the ER stress cascade and heme biosynthesis pathway were analyzed. The expression of glucose-regulated protein 78 (GRP78), a master regulator of ER stress, increased significantly, followed by increased cellular apoptosis. Administration of 5-ALA induced a remarkable increase in HO-1 expression, thus ameliorating PA-induced GRP78 expression and apoptotic signals. BTB and CNC homology 1 (BACH1), a transcriptional repressor of HO-1, was significantly downregulated by 5-ALA treatment. HO-1 induction attenuates PA-induced renal tubular injury by suppressing ER stress. This study demonstrates the therapeutic potential of 5-ALA against lipotoxicity through redox pathway.

Low calf circumference can predict nutritional risk and mortality in adults with metabolic syndrome aged over 80 years

BACKGROUND

Metabolic disorders and malnutrition are a double burden worldwide. The aim was to determine whether low calf circumference (CC) could predict nutritional risk and the cut-off values of CC for predicting nutritional risk in metabolic syndrome (MetS) patients aged over 80 years. We aimed to evaluate the risk factors for predicting mortality in MetS.

METHODS

A total of 514 patients aged over 80 years with MetS were enrolled and followed for 2.5 years. On admission, demographic data, CC, and laboratory parameters were obtained. Patients with a Nutritional Risk Screening 2002 (NRS 2002) total score ≥ 3 were considered to have nutritional risk.

RESULTS

The CC level was significantly lower in the nutritional risk group than in the non-nutritional risk with MetS group (27.1 ± 4.0 cm vs. 30.8 ± 3.9 cm). Logistic regression analysis of nutritional risk revealed that increasing CC (adjusted OR, 0.81; 95% CI, 0.74-0.88) was an independent protective factor against nutrition risk. The best CC cut-off value for predicting nutritional risk according to the NRS 2002 was 28.8 cm. Cox regression multivariate models showed nutritional risk (HR, 2.48; 95% CI, 1.22-5.04) and decreased CC (HR, 2.78; 95% CI, 1.27-5.98) remained independent risk factors for mortality.

CONCLUSION

Decreased CC could predict not only nutritional risk but also mortality in MetS patients aged over 80 years. The elderly who had MetS with nutritional risk should be discovered early, early intervention and early treatment. CC may be a valuable index to screen out this population.

Associations of Serum Insulin-Like Growth Factor 1 with New Cardiovascular Events and Subsequent Death in Hemodialysis Patients: The DREAM Cohort

Aim: Patients with chronic kidney disease (CKD) have elevated risk of death from cardiovascular disease (CVD). A low serum insulin-like growth factor 1 (IGF-1) level is known to predict higher risk for all-cause mortality in incident dialysis patients, although it is unknown whether IGF-1 predicts cardiovascular outcomes.

Methods: This was a prospective cohort study of maintenance hemodialysis patients followed up for 5 years. Serum IGF-1 levels were measured at baseline, and patients were divided into IGF-1 tertiles. The key outcomes were all-cause mortality, a composite of new CVD, and death after new CVD events. Additional outcomes were hospitalization for infection and subsequent death. Association was analyzed using Cox proportional hazards models.

Results: In the 516 patients that were analyzed, we identified 106 all-cause deaths, 190 new CVD events, and 61 subsequent deaths. In addition, there were 169 hospitalizations for infection and 47 subsequent deaths. The risk of all-cause death was the highest in the lowest IGF-1 tertile, and this association remained significant in multivariable-adjusted models. Regarding CVD outcomes, IGF-1 was not associated with new CVD events but significantly associated with subsequent death in adjusted models. Similarly, IGF-1 was not an independent predictor of hospitalization for infection, but it predicted subsequent death.

Conclusions: A low IGF-1 level was not a significant predictor of new CVD events but an independent predictor of subsequent death in hemodialysis patients. Since similar associations with infection outcomes were observed, IGF-1 may be a biomarker of fragility or frailty in this population.

Energy expenditure and nutritional complications of metabolic syndrome and rheumatoid cachexia in rheumatoid arthritis: an observational study using calorimetry and actimetry

OBJECTIVE

Altered energy expenditure may contribute to the nutritional complications of RA, metabolic syndrome (MS) and rheumatoid cachexia (RC). The main aim of this study was to evaluate whether the altered resting energy expenditure (REE) and physical activity (PA)-related energy expenditure (EE) are related to the duration of RA and inflammatory activity and nutritional complications in RA.

METHODS

Among patients with well-characterized RA (duration, activity: DAS28 ESR), we measured REE by indirect calorimetry, and PA-EE by actimetry (SenseWear Armband). MS was defined according to the International Diabetes Federation criteria and RC from DXA body composition analysis. The relations between the characteristics and nutritional complications, and EE were analysed by linear regression.

RESULTS

Fifty-seven patients were included [73% women, age 57 (10) years] with a wide range of disease duration: 3.8 (3.0) years, and DAS28 ESR: 3.9 (1.4). The mean REE was 1486 (256) kcal/day, associated with the DAS28 ESR (β = +0.21, P = 0.02 after adjusting for gender and fat free mass). The prevalence of MS and RC was, respectively, 24 and 18%, and they were unrelated to each other. The patients with MS and/or RC had double the longstanding RA score (P < 0.05), twice the homeostasis model assessment of insulin resistance values (P = 0.052) and halved levels of PA (P < 0.05 for metabolic equivalent tasks (METs) and number of steps/day). Two modifiable factors were associated with the presence of MS and/or RC: a low level of PA as METs [exp(B) = 0.03, P = 0.009] and the use of glucocorticoids [exp(B) = 4.08, P = 0.046].

CONCLUSION

Low levels of PA and treatment by glucocorticoids are associated with the nutritional complications of RA, suggesting the potential for therapeutic interventions.

Use of vitamin D receptor activator, incident cardiovascular disease and death in a cohort of hemodialysis patients

The use of vitamin D receptor activators (VDRAs) is an independent predictor of a lower risk of death from cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). We examined whether the use of VDRAs and other CKD-mineral bone disorder (MBD)-related factors are associated with incident CVD or death after CVD in hemodialysis patients. This is a historical cohort study of 37 690 prevalent hemodialysis patients without previous history of CVD at the end of 2004 extracted from a nationwide registry in Japan. The key exposure was the use of VDRAs, and the outcomes were incident CVD (myocardial infarction, cerebral infarction, cerebral hemorrhage, and sudden death) and death after CVD during the 1-year follow-up. VDRAs were used in 57% of the subjects at baseline. We identified 2433 patients with incident CVD and 397 deaths after the events. In multivariate logistic regression models, independent predictors of incident CVD were non-use of VDRA, higher intact PTH, non-use of calcium-based phosphate-binder, and non-use of non-calcium-based phosphate binder. Risk of death after CVD was not significantly associated with VDRA, whereas it was lower in those with lower corrected calcium, and the risk was higher in those with higher phosphate and in non-users of calcium-based phosphate binders. The use of VDRAs was associated with a lower risk of incident CVD but not with death after CVD in this large cohort of hemodialysis patients. The CKD-MBD-related predictors of poor outcomes are associated with the risk of incident CVD, the risk of death after CVD, or both.

Selected nutraceutic screening by therapeutic effects on doxorubicin-induced chronic kidney disease

SCOPE

The number of patients with chronic kidney disease (CKD) are increasing. Interventions such as controlling hypertension and specific pharmacologic options are recommended. Some nutraceutics may have benefits in this regard.

METHODS AND RESULTS

Naringenin (a flavanon), catechin (a flavanol), and quercetin (a flavonol) and rutin (a flavonol rutinoside) were tried on CKD in a Sprague Dawley rat model. Results indicated quercetin to be the most effective therapeutic candidate with respect to renal edema, hypertension, serum creatinine, hematocrit, cardiopathy, aorta calcification, glomerular amyloidosis, erythrocyte depletion in bone marrow, collagen deposition, expressions of TNF-α, cleaved caspase-3, IκBα, PPARα, and serum insulin. But quercetin was only partially effective in restoring glomerular filtration rate, albuminuria, serum cholesterol, triglyceride, blood urea nitrogen (BUN), uric acid, malondialdehyde, superoxide dismutase; urinary BUN and urinary creatinine. As for signaling, quercetin was completely effective in alleviating the cleaved caspase-3, being only partially effective in suppressing Bax and Bad, restoring Bcl-2, and rescuing DNA damage.

CONCLUSION

The CKD status cannot to be ameliorated by naringenin, rutin, and catechin. Comparatively, quercetin may be a better therapeutic candidate.

Effects of Oral L-Carnitine Supplementation on Lipid Profile, Anemia, and Quality of Life in Chronic Renal Disease Patients under Hemodialysis: A Randomized, Double-Blinded, Placebo-Controlled Trial

In patients on maintenance hemodialysis several factors reduce the body stored carnitine which could lead to dyslipidemia, anemia, and general health in these patients. We evaluated the effect of oral L-carnitine supplementation on lipid profiles, anemia, and quality of life (QOL) in hemodialysis patients. In a randomized, double-blinded, placebo-controlled trial, end-stage renal disease (ESRD) patients on hemodialysis received either L-carnitine 1 g/d (n = 24) or placebo (27 patients) for 16 weeks. At the end of the study, there was a significant decrease in triglyceride (-31.1 ± 38.7 mg/dL, P = 0.001) and a significant increase in HDL (3.7 ± 2.8 mg/dL, P < 0.001) levels in the carnitine group. Decrease in total cholesterol (-6.6 ± 16.0 mg/dL, P = 0.075) and increase in hemoglobin (0.7 ± 1.7 g/dL, P = 0.081) concentrations in the carnitine group were not significant. There was no statistically significant changes in LDL in any group (P > 0.05). Erythropoietin dose was significantly decreased in both the carnitine (-4750 ± 5772 mg, P = 0.001) and the placebo group (-2000 ± 4296 mg, P < 0.05). No improvement was observed in QOL scores of two groups. In ESRD patients under maintenance hemodialysis, oral L-carnitine supplementation may reduce triglyceride and cholesterol and increase HDL and hemoglobin and subsequently reduce needed erythropoietin dose without effect on QOL.

Comparative effectiveness of incident oral antidiabetic drugs on kidney function

Diabetes is a major cause of chronic kidney disease, and oral antidiabetic drugs are the mainstay of therapy for most patients with Type 2 diabetes. Here we evaluated their role on renal outcomes by using a national Veterans Administration database to assemble a retrospective cohort of 93,577 diabetic patients who filled an incident oral antidiabetic drug prescription for metformin, sulfonylurea, or rosiglitazone, and had an estimated glomerular filtration rate (eGFR) of 60 ml/min or better. The primary composite outcome was a persistent decline in eGFR from baseline of 25% or more (eGFR event) or a diagnosis of end-stage renal disease (ESRD). The secondary outcome was an eGFR event, ESRD, or death. Sensitivity analyses included using a more stringent definition of the eGFR event requiring an eGFR <60 ml/min per 1.73 m(2) in addition to the 25% or more decline; controlling for baseline proteinuria thereby restricting data to 15,065 patients; and not requiring persistent treatment with the initial oral antidiabetic drug. Compared to patients using metformin, sulfonylurea users had an increased risk for both the primary and the secondary outcome, each with an adjusted hazard ratio of 1.20. Results of sensitivity analyses were consistent with the main findings. The risk associated with rosiglitazone was similar to metformin for both outcomes. Thus, compared to metformin, oral antidiabetic drug treatment with sulfonylureas increased the risk of a decline in eGFR, ESRD, or death.

Chronic kidney disease, dyslipidemia, and atherosclerosis

Patients with chronic kidney disease (CKD) are at an increased risk not only for end-stage kidney disease (ESKD) but also for cardiovascular disease (CVD). In this review article, we summarize the current evidence of CKD as a high-risk condition for CVD based on reports from Japan and other countries to draw attention to the close clinical association between CKD and CVD. Several epidemiologic studies have shown that the presence of CKD and reduced renal function are independent predictors of CVD also in Japan. According to a post-hoc analysis of CASE-J, the power of CKD as a predictor of CVD is as strong as diabetes mellitus and a previous history of ischemic heart disease. CKD worsens classical risk factors including hypertension and dyslipidemia, and dyslipidemia is associated with increased thickness and stiffness of large arteries independent of major confounders. A post-hoc analysis of MEGA indicates that lipid-lowering therapy with statins reduces the risk of CVD, and that it appears to be more efficacious in patients with than without CKD. These reports from Japan and other countries suggest that CKD should be regarded as a high-risk condition comparable to diabetes mellitus, and that strict control of dyslipidemia would be beneficial in preventing CVD, at least early stages of CKD.

Elevated non-high-density lipoprotein cholesterol (non-HDL-C) predicts atherosclerotic cardiovascular events in hemodialysis patients

BACKGROUND AND OBJECTIVES

Dialysis patients show "reverse causality" between serum cholesterol and mortality. No previous studies clearly separated the risk of incident cardiovascular disease (CVD) and the risk of death or fatality after such events. We tested a hypothesis that dyslipidemia increases the risk of incident atherosclerotic CVD and that protein energy wasting (PEW) increases the risk of fatality after CVD events in hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational cohort study in 45,390 hemodialysis patients without previous history of myocardial infarction (MI), cerebral infarction (CI), or cerebral bleeding (CB) at the end of 2003, extracted from a nationwide dialysis registry in Japan. Outcome measures were new onsets of MI, CI, CB, and death in 1 year.

RESULTS

The incidence rates of MI, CI, and CB were 1.43, 2.53, and 1.01 per 100 person-years, and death rates after these events were 0.23, 0.21, and 0.29 per 100 person-years, respectively. By multivariate logistic regression analysis, incident MI was positively associated with non-HDL cholesterol (non-HDL-C) and inversely with HDL cholesterol (HDL-C). Incident CI was positively associated with non-HDL-C, whereas CB was not significantly associated with these lipid parameters. Among the patients who had new MI, CI, and/or CB, death risk was not associated with HDL-C or non-HDL-C, but with higher age, lower body mass index, and higher C-reactive protein levels.

CONCLUSIONS

In this hemodialysis cohort, dyslipidemia was associated with increased risk of incident atherosclerotic CVD, and protein energy wasting/inflammation with increased risk of death after CVD events.

Definition of Metabolic Syndrome in Peritoneal Dialysis

Metabolic syndrome (MetS) is defined as a cluster of risk factors for type 2 diabetes and cardiovascular disease; it is also an independent risk factor for developing chronic kidney disease (CKD) in the general population. Therefore, CKD has many similarities and associations with MetS, and the individual risk factors constituting MetS—especially insulin resistance and glucose intolerance, hypertension, dyslipidemia, and obesity—are also common features of the early stages of CKD. In the later stages of CKD, uremia per se and uremic complications such as fluid retention, protein–energy wasting, inflammation, and oxidative stress further contribute to an increase in the prevalence of MetS in CKD patients. In addition, PD patients exposed to glucose-based PD fluids have an increased risk of developing metabolic complications. The broad use of MetS in clinical research has raised the awareness of the public and of individual patients concerning the value of lifestyle interventions. However, the definition and pathogenesis of MetS are still debated, and no standardized definition nor proven prognostic value has been established for MetS as a cluster of risk factors for diabetes or cardiovascular disease in PD patients. Furthermore, considering the paradoxical associations of some of the risk factors in MetS with decreased mortality, another set of risk factors—those specific to patients with uremia (for example, inflammation and malnutrition)—and the appropriate cut-off levels to individual MetS risk factors should be taken account at the same time. Also, the benefit of interventions targeting these risk factors should be clarified in further clinical studies.

[Frequency and characteristics of metabolic disorders in patients on haemodialysis]

BACKGROUND/AIM

. Metabolic syndrome and malnutrition represent metabolic abnormalities which significantly characterize patients on haemodialysis. The aim of the study was to determine the incidence and find characteristics of metabolic disbalance in patients on haemodialysis.

METHODS

The study involved 124 patients on chronic haemodialysis at the Clinical Centre Kragujevac. There were analyzed demographic and anthropometric characteristics of the examined patients. Of clinical characteristics, there were determined smoking habit, time on dialysis, arterial pressure; of comorbid states there were recorded heart diseases and diabetes mellitus. Routine biochemical analyses were carried out by a standard laboratory procedure.

RESULTS

Metabolic syndrome was found in 29.8% of the examined patients. The patients with metabolic syndrome were older as compared to the patients without metabolic syndrome (58.45 +/- 12.91 vs 52.25 +/- 11.63 years). The values of systolic pressure (143.88 +/- 19.75 vs 133.01 +/- 22.93 mmHg; p = 0.014), body mass index (21.2 +/- 3.71 vs 19.4 +/- 2.88 kg/m2;p = 0.001), fat body mass (19.57 +/- 8.47 vs 16.45 +/- 5.82%; p = 0.0002) and waist scope (89 +/- 12.54 vs 96 +/- 12.34 cm; p = 0.0001) were significantly higher in the patients with metabolic syndrome as compared to those without metabolic syndrome. The values of erythrocytes (3.4 +/- 0.45 vs 19 +/- 0.53 x 10(12); p = 0.04) and hemoglobin (107 +/- 15.76 vs 101 +/- 13.87 g/l; p = 0.009), glycaemia (9.5 +/- 8.15 vs 5.6 +/- 1.4 mmol/l; p = 0.04) triglycerides (2.44 +/- 1.8 vs 1.41 +/- 0.64 mmol/l; p = 0.007), HDL cholesterol (1.11 +/- 0.19 vs 0.82 +/- 0.25 mmol/l; p = 0.005) and albumins (32.5 +/- 5.6 vs 29.5 +/- 3.7 g/l; p = 0.007) were statistically higher in the patients with metabolic syndrome than in patients without disturbance. Diabetes mellitus was a significant etiological factor of renal insufficiency in the patients with metabolic syndrome (p = 0.008).

CONCLUSION

In our study approximately 30% of patients on haemodialysis had pronounced metabolic syndrome. The older, more obese men with increased levels of triglycerides and glucose in the serum dominated among them. Diabetes mellitus was a leading etiological factor of renal insufficiency in these patients.

Fasting Serum Ghrelin Level is Associated with Metabolic Syndrome in Peritoneal Dialysis Patients

⋄ Background

Serum ghrelin levels are elevated in uremic patients. However, no data are available on the relationship between metabolic syndrome and serum ghrelin levels in peritoneal dialysis (PD) patients.

⋄ Methods

Metabolic syndrome and its components were defined using diagnostic criteria recommended by the International Diabetes Federation. Fasting serum samples were taken from 30 PD patients. Serum ghrelin levels were measured by using a commercial enzyme-linked immunosorbent assay kit.

⋄ Results

Of the 30 PD patients, 53.3% (16/30) had metabolic syndrome. Fasting serum ghrelin corrected inversely with metabolic syndrome among these PDs patients ( p = 0.002). By odds ratio (OR) analysis of metabolic syndrome and metabolic syndrome diagnostic criteria, the predictors for metabolic syndrome are fasting glucose [OR: 39.00; 95% confidence interval (CI): 3.80 to 399.85; p < 0.001], triglycerides (OR: 37.50; 95% CI: 3.64 to 386.51; p < 0.001), and waist circumference (OR: 4.20; 95% CI: 1.95 to 9.03; p < 0.001). Univariate linear regression analysis showed that body weight ( r = –0.461, p = 0.010), waist circumference ( r = –0.390, p = 0.033), and body mass index ( r = –0.438, p = 0.016) were negatively correlated with serum ghrelin, and serum high density lipoprotein [HDL ( r = 0.626, p < 0.001)] was positively correlated with serum ghrelin. Multivariate forward stepwise linear regression analysis of the significant variables showed that HDL ( R2 change = 0.392; p < 0.001) was the independent predictor of serum ghrelin in PD patients and explained 39.2% of the variance.

⋄ Conclusions

These results indicate an inverse association between circulating fasting ghrelin and metabolic syndrome in PD patients. Serum HDL was associated with serum ghrelin among PD patients.

Plasma and urine levels of resistin and adiponectin in chronic kidney disease

BACKGROUND

Subjects with chronic kidney disease (CKD) have an increased risk of developing coronary atherosclerosis. Adipocyte hormones, resistin and adiponectin are implicated in insulin resistance and atherosclerosis. However, few studies in the literature address the role of adipocyte hormones in CKD. The aim of this study was to compare the levels of resistin, adiponectin and other inflammatory markers in subjects with CKD with those of the control subjects.

MATERIALS AND METHODS

In a cross-sectional study, we measured basal metabolic panel, fasting lipid panel and levels of glucose, resistin, adiponectin, insulin, C-reactive protein (CRP) and TNF-alpha in 43 subjects with CKD compared with those of 34 control subjects. We also measured the resistin and adiponectin levels in urine samples (16).

RESULTS

Subjects with CKD have increased insulin levels and insulin resistance index (IRI). Compared with controls, subjects with CKD had increased levels of resistin (5.12+/-3.2 vs.7.5+/-5.9; p<0.05), CRP (1.7+/-2.2 vs. 5.97+/-6.0; p<0.0005), and TNF-alpha (3.4+/-2.0 vs. 5.2+/-3.5; p<0.005). Resistin levels correlate with CRP and TNF-alpha, even with BMI as a covariate. Although 60% of subjects with CKD have CAD, e plasma levels of adiponectin were not decreased in subjects with CKD compared with controls (17.02+/-9.8 vs. 16.40+/-9.0 with p value 0.78). Urinary adiponectin levels correlate inversely with GFR (r=-0.4; p<0.05) and plasma adiponectin levels (r=0.9; p<0.0001).

CONCLUSIONS

Subjects with CKD had normal levels of plasma adiponectin despite the adverse metabolic environment for CAD. In addition, this study demonstrates the relationship between resistin and TNF-alpha in subjects with CKD and suggests that resistin may play a role in the sub-clinical inflammation associated with CKD, suggesting that adiponectin clearance may be decreased as shown by the inverse correlation of urinary adiponectin with GFR.

Malnutrition after vascular surgery: are patients with chronic renal failure at increased risk?

BACKGROUND

The deleterious effects of perioperative malnutrition on recovery after general surgery are established. Since the effects of perioperative malnutrition on recovery after vascular surgery are not known, we examined the effects of nutritional status, and risk factors predictive of malnutrition, on outcome after vascular surgery.

METHODS

The records of all open index vascular cases (abdominal aortic aneurysm [AAA] repair, carotid endarterectomy [CEA], lower extremity bypass) performed at the Veterans Affairs (VA) Connecticut between July 2004 and June 2005 were reviewed. The primary outcome was mortality; secondary outcomes included infection and nutritional risk index (NRI) scores.

RESULTS

Sixty-eight open vascular cases were performed during the study period. Nutritional depletion developed in 55% of patients and was more likely in patients undergoing AAA (85%) or bypass (77%) than CEA (30%; P = .0005). Patients who developed malnutrition had similar mortality as patients who did not develop postoperative malnutrition (6.1% vs. 3.7%; P = .68); however, malnourished patients had higher rates of postoperative infection (24.2% vs. 3.7%; P = .03). Chronic renal failure was the only patient-associated risk factor predictive of postoperative nutritional depletion (odds ratio 5.9, confidence interval 1.0 to 33.6; P = .04).

CONCLUSIONS

Patients undergoing major open vascular surgery have high rates of postoperative malnutrition, with patients undergoing AAA repair having the highest rates of postoperative malnutrition and infection. Patients with chronic renal failure undergoing vascular surgery are associated with increased risk for postoperative malnutrition and may be a group to target for perioperative risk factor modification and nutritional supplementation.

Increased blood pressure in adult offspring of families with Balkan endemic nephropathy: a prospective study

BACKGROUND

Previous studies have linked smaller kidney dimensions to increased blood pressure. However, patients with Balkan Endemic Nephropathy (BEN), whose kidneys shrink during the course of the disease, do not manifest increased blood pressure. The authors evaluated the relationship between kidney cortex width, kidney length, and blood pressure in the offspring of BEN patients and controls.

METHODS

102 offspring of BEN patients and 99 control offspring of non-BEN hospital patients in the Vratza District, Bulgaria, were enrolled in a prospective study and examined twice (2003/04 and 2004/05). Kidney dimensions were determined using ultrasound, blood pressure was measured, and medical information was collected. The parental disease of BEN was categorized into three groups: mother, father, or both parents. Repeated measurements were analyzed with mixed regression models.

RESULTS

In all participants, a decrease in minimal kidney cortex width of 1 mm was related to an increase in systolic blood pressure of 1.4 mm Hg (p = 0.005). There was no association between kidney length and blood pressure. A maternal history of BEN was associated with an increase in systolic blood pressure of 6.7 mm Hg (p = 0.03); paternal BEN, +3.2 mm Hg (p = 0.35); or both parents affected, +9.9 mm Hg (p = 0.002). There was a similar relation of kidney cortex width and parental history of BEN with pulse pressure; however, no association with diastolic blood pressure was found.

CONCLUSION

In BEN and control offspring, a smaller kidney cortex width predisposed to higher blood pressure. Unexpectedly, a maternal history of BEN was associated with average increased systolic blood pressure in offspring.

Plasma Lipoprotein Abnormalities in Hemodialysis Patients—Clinical Implications and Therapeutic Guidelines

Patients with advanced stages of chronic kidney disease (CKD) have an increased risk of death from cardiovascular disease (CVD). Dyslipidemias are associated with atherosclerotic vascular changes and the risk of occurrence of acute myocardial infarction in hemodialysis patients. However, management of dyslipidemia in hemodialysis patients does not appear to be actively carried out in routine practice. Presumably, there are three reasons for this reluctance to lipid-lowering in hemodialysis patients. First, there are epidemiological data showing the inverse relationship between cholesterol and mortality rate; a high cholesterol predicts a better survival. Second, lipids are not usually measured using standard fasting serum, but a non-fasting specimen. Third, although hypertriglyceridemia is the most common abnormality, fibrates are contraindicated in patients with renal failure because of a high risk of rhabdomyolysis. These issues are discussed in the current review article. Based on published work, lipid lowering would not increase the death rate if carried out without worsening malnutrition. The National Kidney Foundation K/DOQI Clinical Practice Guidelines recommend a reduction in fasting LDL-C below 100 mg/dL for the prevention of CVD in dialysis patients. Practically, however, the use of non-HDL-C measured by casual blood samples might be sufficient for the risk assessment in many hemodialysis patients. Statins are a good choice for lipid-lowering in dialysis patients. Furthermore, lipoprotein profile might be improved by an inventive use of dialyzer membranes, dialysate solutions, and other dialysis-related medications. For severe hypercholesterolemia, LDL-apheresis is another choice for consideration. Further studies are needed to clearly prove the benefit of lipid reduction in hemodialysis patients and those with CKD at earlier stages.

Body Composition and Cardiovascular Risk in Hemodialysis Patients

Death rate is unacceptably elevated in end-stage renal disease patients treated with hemodialysis. Excessive body fat, or obesity, is the well-known risk factor for cardiovascular disease and other health problems in the general population. However, hemodialysis patients with a higher body mass index (BMI) have a lower risk of death, as shown by many studies. There are several explanations for the paradox of BMI in dialysis patients. First, although body mass is composed of fat mass and fat-free mass (lean mass), it is unknown which is more important, fat mass or lean mass, in predicting outcome of hemodialysis patients. Second, it is also possible that functions of adipose tissue are altered in renal failure so that accumulation of body fat leads to less atherogenicity and beneficial properties become predominant. Third, an increased fat mass may be protective against death after harmful events. In this article, we explore these possibilities using either the data of our own cohort of hemodialysis patients or the existing registry data of Japan. We conclude that in hemodialysis patients, fat mass rather than lean mass plays a protective role against mortality, that the fat mass-adipocytokine relationship is altered, and that a low BMI is associated with increased risk of fatality after cardiovascular events rather than the risk of occurrence of such events.

Asymmetrical (ADMA) and symmetrical dimethylarginine (SDMA) as potential risk factors for cardiovascular and renal outcome in chronic kidney disease - possible candidates for paradoxical epidemiology?

BACKGROUND

Asymmetrical dimethylarginine (ADMA) is an inhibitor of nitric-oxide synthase. It has been linked to atherosclerotic risk in the general population as well as in end-stage renal disease patients (ESRD), whereas symmetrical dimethylarginine (SDMA) is thought to be biological inactive. Prospective data concerning the role of both dimethylarginines are rare in patients with chronic kidney disease.

METHODS

200 Patients with chronic kidney disease (mean age 57.6 +/- 13.0 years, 69 female, 131 male); 82 with chronic renal failure (CRF), 81 on maintenance haemodialysis (HD) and 37 renal transplant recipients (RTR) were prospectively followed for 24 months. ADMA and SDMA were measured by HPLC. The relation of plasma levels of ADMA and SDMA together with conventional risk factors for the cardiovascular and renal outcome was investigated with Cox proportional hazards model.

RESULTS

Mean serum levels of SDMA were significantly increased in all groups compared to the control group (P <or= 0.0005), ADMA was increased only in HD and RTR (P <or= 0.004). Forty-seven cardiovascular events (CVE) occurred during follow-up, 35 patients died, and 39 patients reached ESRD. Multivariate analysis showed diabetes (RR 3.072, P = 0.01), ESRD (RR 11.915, P < 0.0005), elevated CRP levels (RR 3.916, P < 0.0005) and surprisingly a lower ADMA level (RR 0.271, P = 0.008) as independent risk factors for CVE. Serum creatinine (RR 11.378, P = 0.001), haemoglobin (RR 0.710, P = 0.038 for an increment of 1 mmol/l), and SDMA levels (RR 1.633, P = 0.006, per 1 micromol/l increment) were predictors for the progression to ESRD.

CONCLUSIONS

Data from a heterogeneous group of patients with chronic kidney disease provide evidence that conventional risk factors seem to play a more important role than elevated serum levels of ADMA or SDMA for cardiovascular events. Increasing serum SDMA concentration seems to play an additive role for the renal outcome besides serum creatinine and haemoglobin levels. Whether ADMA might possibly be a candidate for the phenomenon of "paradoxical epidemiology" in chronic kidney disease needs further investigation.