Aerobic Exercise Training and Nontraditional Cardiovascular Risk Factors in Hemodialysis Patients: Results from a Prospective Randomized Trial.

INTRODUCTION: Chronic kidney disease (CKD) patients have a high incidence of cardiovascular diseases (CVD) which increases their morbidity and mortality. A sedentary lifestyle in CKD is directly linked to the onset of CVD. Physical activity can bring beneficial effects to CKD patients. AIMS: The aim of this study was assess the impact of aerobic training on nontraditional cardiovascular risk factors in CKD patients on hemodialysis. MATERIALS AND METHODS: This is a prospective, controlled, and randomized clinical trial with analysis of intention to treat. Thirty patients underwent an exercise treadmill test, an arterial stiffness evaluation, echocardiography and analysis of endothelial reactivity, and carotid ultrasound and laboratorial tests, including analysis of serum aldosterone. The intervention group (IG) (n =15) underwent aerobic exercise during hemodialysis 3 times a week for 4 months. The control group (CG) (n =15) had no intervention. All of the patients were reassessed after 4 months. RESULTS: In the IG, there was a statistically significant improvement in flow-mediated vasodilation (FMV; p = 0.002) and a reduction in left ventricular hypertrophy (p = 0.006) and serum aldosterone (p = 0.016). There was an increase in C-reactive protein in the CG (p = 0.002). CONCLUSION: This aerobic training protocol was able to improve endothelial function with enhanced FMV and reduce left ventricular hypertrophy and serum aldosterone, which could have a positive impact on the reduction of nontraditional cardiovascular risk factors in CKD patients on hemodialysis.

Influence of Intradialytic Aerobic Training in Cerebral Blood Flow and Cognitive Function in Patients with Chronic Kidney Disease: A Pilot Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Changes in cerebral blood flow may play an important role in cognitive impairment among hemodialysis (HD) patients. Physical activity has a promising role in delaying cognitive impairment in general population, but there are only a few studies in HD to confirm this finding. We aimed to evaluate the effects of intradialytic aerobic training on cerebral blood flow and cognitive impairment in HD. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: This is a pilot, controlled, randomized trial. Fifteen patients underwent intradialytic aerobic training 3 times a week for 4 months. The control group was comprised of another 15 patients. RESULTS: Trained patients had a statistically significant improvement of cognitive impairment and basilar maximum blood flow velocity. The proportion of arteries with increased flow velocity was statistically significant between groups. CONCLUSIONS: Intradialytic aerobic training improves cognitive impairment and cerebral blood flow of patients in HD, suggesting a possible mechanism improving cognitive impairment by physical training in HD. These data still need to be confirmed by major trials.

Attenuation of Renal Functional Decline Following Angioplasty and Stenting in Atherosclerotic Renovascular Disease.

BACKGROUND: To date, renal revascularization has not been shown to be advantageous when compared to optimized medical treatment in patients with atheromatous renovascular disease (ARVD). This study aims to investigate the effect of revascularization in patients with pre-intervention worsening renal function and in those with stable renal function. PATIENTS AND METHODS: In this single-centre observational study, patients who were diagnosed with at least 60% angiographic stenosis unilaterally or bilaterally between January 1996 and October 2008 and who were followed-up until February 2011 were retrospectively analysed. Evolution of renal function was determined from the slope of reciprocal of serum creatinine (RCr-slope) before and after diagnostic angiography or revascularization; this required 5 or more creatinine measurements before and at least another 5 measurements post-procedure. Patients were divided into 2 groups: one comprising patients with negative RCr-slope before the procedure and a second group of patients with prior positive RCr-slope. A stepwise, adjusted logistic regression was used to determine the OR of revascularization on attenuation of RCr-slope. RESULTS: Data for 52 patients were analysed. Median age was 64 (58-72) and median follow-up was 15 (8-34) months. Only patients with a negative RCr-slope (-0.0078 (95% CI -0.0174, -0.0033) dl/mg/month) who underwent revascularization manifested an improved RCr-slope during follow-up (+0.0013 (95% CI -0.0002, 0.0039) dl/mg/month, p < 0.001). This finding remained statistically significant even after the adjustment for proteinuria and bilateral arterial disease. CONCLUSION: Revascularization may be indicated for patients with ARVD and progressively worsening renal function. This patient subgroup should ideally be evaluated in future randomized controlled trials.

Aldosterone is associated with left ventricular hypertrophy in hemodialysis patients.

OBJECTIVES: Patients with chronic kidney disease present a higher degree of left ventricular hypertrophy than expected for hypertension levels. In chronic kidney disease the plot between the quotient extracellular water/total body water and aldosterone is shifted up and to the right. There are few studies that verified the role of aldosterone in cardiac remodeling in this set of patients. The aim of this study was to evaluate the relationship between serum aldosterone and left ventricular mass index in patients with chronic kidney disease on hemodialysis. METHODS: The patients were submitted to clinical and laboratory evaluation, bioelectrical impedance, echocardiography and ambulatory blood pressure monitoring. The 27 patients included were divided into two groups according to aldosterone level and compared with each other. RESULTS: The group of patients with higher aldosterone levels had higher left ventricular mass index. These groups were heterogeneous with regard to ambulatory systolic blood pressure, body mass index, and aldosterone levels and homogeneous with regard to the quotient extracellular water/total body water, renin-angiotensin-aldosterone system blockers, beta blocker use and other clinical characteristics. The association between aldosterone levels and left ventricular mass index was adjusted to confounding variables by a multiple linear regression analysis in which aldosterone was independently associated with left ventricular mass index. CONCLUSION: The data presented are consistent with a pathogenic role of aldosterone in left ventricular hypertrophy in patients with chronic kidney dialysis in dialysis patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01128101.

Total body water and failure to control blood pressure by medication in hemodialysis patients.

BACKGROUND: Volume overload is the main factor responsible for the pathogenesis of hypertension in dialysis patients. Few studies have evaluated the interpretation of the parameters obtained by bioelectrical impedance (BIA) to manage these patients. The aim of this study was to assess the best cutoff level of volume overload obtained by BIA able to predict the absence of hypertension control in hemodialysis patients. METHODS: Volume overload was calculated as the difference between total body water (TBW) measured by bioimpedance and TBW estimated by the Watson formula in chronic stable hemodialysis patients. Inadequate control of blood pressure (BP) was defined as the mean of measurements obtained before five hemodialysis sessions ≥140 × 90 mm Hg. The best cutoff level of volume overload assessed by BIA able to predict the absence of BP control in patients on chronic hemodialysis was determined by the receiver operating characteristic (ROC) curve using the Youden method. RESULTS: We included 205 patients, 53% male, aged 56 ± 14.5 years. The largest area under the ROC curve was found for predialysis volume overload (0.660, 95% CI 0.556-0.765, p = 0.004). The ROC curve of postdialysis volume overload also reaches statistical significance. The best cutoff point was found for predialysis volume overload ≥1.4 liters with a sensitivity of 69% and a specificity of 67%. CONCLUSION: The association of TBW and inadequate BP control highlights the importance of volume management in hemodialysis patients. Predialysis volume overload of 1.4 liters was the parameter that best discriminated the presence of inadequate BP control.

Markers of uremia and pericardial effusion in peritoneal dialysis.

BACKGROUND: Inadequate dialysis causes accumulation of toxic residues that may lead to the development of dialysis-associated pericardial effusion, but several other factors could be associated with this abnormality. The purpose of this study was to evaluate clinical risk factors to asymptomatic pericardial effusion in peritoneal dialysis. METHODS: This cross-sectional study included 34 patients aged ≥ 18 years on peritoneal dialysis for at least 3 months, who showed no symptomatic pericardial effusion, hepatic cirrhosis, neoplasias, lupus or amputations, none in minoxidil use. Asymptomatic pericardial effusion was diagnosed by echocardiography. Risk factors were evaluated by logistic regression and Roc curve. Significance level was set at P < 0.05. RESULTS: Patient age was 51 ± 15.9 years. Of the 34 patients enrolled, 16 were men and 11 diabetic. Five of them presented pericardial effusion. Logistic regression identifies low hemoglobin level (RR 0.454 CI 95%: 0.225-0.913; P = 0.027), low phase angle (RR 0.236 CI 95%: 0.057-0.984; P = 0.048) and low Kt/V (RR 0.001 CI 95%: 0.0-0.492; P = 0.03) as risk factors to pericardial effusion. Roc curve showed that hemoglobin levels below 12.2 g/dL, Kt/V lower than 1.9 and phase angle lower than 4.5° were the best cutoffs to predict pericardial effusion. Four patients showed these three parameters in the unfavorable range, and all these four patients presented pericardial effusion. The other patient with pericardial effusion had two of these parameters reduced. CONCLUSIONS: These findings corroborate the hypothesis that uremia plays a significant role in the pathogenesis of dialysis-associated pericardial effusion.

Frequency of coronary artery disease in patients with renal artery stenosis without clinical manifestations of coronary insufficiency.

Atherosclerotic renal artery stenosis (RAS) and coronary artery disease (CAD) arise from the same multiple risk factors. The purpose of this study was to assess the frequency of previously undiagnosed CAD in patients with angiographically confirmed RAS, by conducting coronary arteriography in the same setting. Of 57 consecutive patients referred for renal arteriography on clinical grounds during a 14-month period, 28 had no RAS and 6 had RAS, but previously documented CAD. Of the remainder 23 patients, 17 (74%; CI 56%-92%) had both RAS and CAD (7 single vessel, 4 two-vessel, and 7 multivessel disease). The clinical characteristics, such as age, blood pressure (BP) levels, signs of heart failure, were no different between those with and without CAD, although the 4 diabetic patients, the 4 patients with fundoscopic findings of grade III retinopathy, 11 of 14 with peripheral arterial disease, and 7 of 8 patients with prior stroke belonged in the CAD group. None developed complications as a result of the two consecutive procedures. The data suggest that in patients with RAS the frequency of silent CAD is high and cannot be predicted on clinical grounds alone, therefore coronary angiography should be routinely recommended in the same setting.

Influence of fluid volume variations on the calculated value of the left ventricular mass measured by echocardiogram in patients submitted to hemodialysis.

The left ventricular mass (LVM) measurement is of major importance for renal patients, as ventricular hypertrophy is an important prognostic index. The echocardiogram of the ventricular mass is larger before than it is after hemodialysis, which can confuse data interpretation. The aim of this work is to study the influence of alterations in fluid volume on the variations in measurements of ventricular mass observed during the course of a hemodialysis. Sixteen patients with chronic renal insufficiency in hemodialysis were evaluated at the Dialysis Unit of the University Hospital-UNESP, Botucatu, São Paulo State. The left ventricular mass was calculated from echocardiograms taken before and after hemodialysis and simultaneous ultra-filtration (12 patients: UF GROUP) and before and after hemodialysis isovolemic phase with sequential ultra-filtration (10 patients: ISO GROUP). Six of these patients were submitted to measurements of left ventricular mass before and after hemodialysis in both isovolemic and simultaneous ultra-filtration procedures. In the UF group, there was significant reduction in the following parameters before and after dialysis: diastolic diameter from 54.0 +/- 6.0mm to 45.6 +/- 7.6mm; left ventricular mass from 342 +/- 114 g to 265 +/- 117 g; and its respective index (IMVE) from 214 +/- 68 g/m2 to 168 +/- 71 g/m2. The ISO group showed no statistically significant variation. The behavior of the variables of six patients submitted to both observations confirm these results. In conclusion, the variations in echocardiogram measurements of the left ventricula mass relating to hemodialysis appear to be induced by alterations of the volemic condition.