Cardiac function and structure in patients with chronic renal failure

The long-term consequences of cardiac alterations in children with chronic renal failure (CRF) and after renal transplantation (TX) are largely unknown. Studies in adults with end-stage renal disease (ESRD) assume that the fate of many pediatric patients is determined by a high cardiovascular morbidity and mortality. This review describes clinical manifestations, pathophysiology, cardiac function and structure, and management of heart disease in children with CRF and post transplant. Echocardiography and Doppler ultrasonography allow differentiation of three functional disturbances: hypercirculation, systolic left ventricular (LV) dysfunction, and diastolic LV dysfunction, in addition to analysis of LV size and myocardial mass. From adult studies LV hypertrophy is recognized as an early prognostic marker of cardiovascular disease. It is present in about half of children with ESRD and after TX. It may regress, at least in part, by control of hypertension, hypervolemia, and anemia. Experimental studies have shown that, independent of these hemodynamic complications, uremia is associated with structural abnormalities of the heart, which were also described in adult patients with ESRD. These lesions consist mainly of hypertrophy of cardiomyocytes, interstitial fibrosis, and vascular changes (rarefied capillaries, thickened arteriolar walls). Cardiac complications in children with CRF and after TX deserve regular clinical and echocardiographic monitoring in order to minimize later cardiovascular morbidity by appropriate treatment. Received: 3 December 1998 / Revised: 16 April 1999 / Accepted: 19 April 1999     

Effects of atorvastatin on renal function in patients with chronic renal failure.

Sir, We read with great interest the paper recently published byVan Dijk et al. [1]. In that study the authors showed that a4-week treatment with simvastatin (40 mg/day) was able to increaseglomerular filtration rate (GFR) and renal plasma flow (RPF)in normotensive patients with polycystic renal disease and normal     

Small intestinal function and structure in patients with chronic renal failure

We studied 24 patients with end-stage chronic renal failure not treated with hemodialysis (CRF1) and 16 patients on regular hemodialysis (CRF2), to investigate the digestive, absorptive and morphological aspects of the small intestinal mucosa. Serum d-xylose test and biochemical parameters of absorption (serum calcium and proteins) were determined. Jejunal mucosal biopsies were obtained and tissue homogenates assayed for disaccharidases (sucrase, maltase and lactase) and dipeptidases (glycyl-glycinase, leucyl-glycinase and leucyl-aminopeptidase). Histological changes were classified according to the severity of abnormality and compared with biopsies obtained from control subjects. Serum d-xylose test, calcium and proteins were normal in patients with CRF. Maltase specific activity was higher in CRF1 than in controls (p less than 0.05). Lactase and leucyl-aminopeptidase showed a tendency to decrease in CRF, but this difference did not reach statistical significance. Sucrase, glycyl-glycinase and leucyl-glycinase specific activity in CRF was similar to the control group. Histological changes of the small intestinal mucosa of mild to moderate degree were noted in 68% of patients with CRF vs 36% in control subjects (p less than 0.01). No significant difference was noted in the incidence of absorptive, enzymatic (with the exception of maltase) and histological changes between the two groups of patients with CRF. These changes are not influenced by hemodialysis, a long-term treatment averaging 6 months, they appear to represent primary manifestations of CRF and may be related to the nutritional status of patients with CRF.     

Changes in pulmonary function in patients with chronic renal failure after successful renal transplantation

OBJECTIVE: Pulmonary function abnormalities have been described in patients with chronic renal failure. There are very few longitudinal studies showing the effect of renal transplantation on pulmonary function. We aimed to study the effects of renal failure on pulmonary functions and to observe the changes following successful renal transplantation. MATERIAL AND METHODS: Patients with end-stage renal failure (n=25) of various etiologies who presented to the renal transplant unit of a teaching hospital were included in this prospective, longitudinal study. Patients with a prior history of pulmonary disease and chronic smokers were excluded. Pulmonary function tests were performed and blood gases evaluated before and 6 months after successful renal transplantation. RESULTS: Most patients showed pulmonary function abnormalities which improved significantly after transplantation. The mean vital capacity increased from 2.89 (95% CI 2.63-3.15) l pre-transplantation to 3.32 (95% CI 3.09-3.54) l post-transplantation (p<0.001), indicating that subjects had a restrictive pulmonary function defect which improved after transplantation. The large airways were normal, as evidenced by normal forced expiratory volume in the first second:forced vital capacity ratios. There was significant small airways dysfunction, as shown by low maximal mid-expiratory flow rates, which tended to improve after renal transplantation (p=0.013). There was also a highly significant (p<0.001) improvement in maximal voluntary ventilation (MVV) after transplantation. The MVV test is a composite test which measures all aspects of pulmonary function, including respiratory muscle strength. However, not all patients achieved normal pulmonary function due to uremia-induced irreversible pre-transplantation changes. CONCLUSION: Pulmonary function abnormalities are common in patients with chronic renal failure but can be significantly ameliorated following successful renal transplantation.     

高龄肾功能衰竭患者肾脏替代疗法的选择

对５６例高龄尿毒症患者采用不同肾脏替代疗法的结果进行分析。２３例采取肾移植，３３例为血液透析。结果移植组死亡率低于透析组，但近期死亡率高，生活质量移植组明显优于透析组，死亡原因与接受替代疗法前的伴随疾病有关。     

Autonomic function in patients with chronic renal failure on intermittent haemodialysis.

The cardiovascular responses to the Valsalva manoeuvre and sustained handgrip were measured in 26 patients with chronic renal failure treated with intermittent haemodialysis. Twelve (50%) had an abnormal Valsalva response and ten (45%) had an abnormal handgrip response. There was a reduction in the beat-to-beat variation of heart rate at rest in those patients who had abnormal Valsalva manoeuvres, independent of age or the resting heart rate. It is concluded that autonomic nerve fibres may be damaged in patients with chronic renal failure on intermittent haemodialysis in the absence of symptoms of autonomic neuropathy. These studies suggest three simple ways of testing autonomic function in haemodialysis patients which could routinely be performed to detect patients at risk of developing an abnormal reaction to volume depletion during haemodialysis.     

Platelet function in dialyzed and non-dialyzed patients with chronic renal failure.

Platelet function studies were performed on healthy volunteers, patients with stable chronic renal failure, hospital dialysis patients and home dialysis patients. In the non-dialyzed patients with chronic renal failure, there was inverse exponential relationship between serum creatinine and platelet adhesiveness indicating progressive impairment of platelet adhesiveness with creatinines in excess of 6 mg/100 ml. In the dialysis population there was an inverse linear relationship between platelet adhesiveness and pre-dialysis creatinine values. Platelet aggregation by ADP was normal in chronic renal failure patients with serum creatinines less than 6 mg/100 ml but was impaired in others. Both groups of dialysis patients also had impaired platelet aggregation but improvement appears obtainable by home dialysis. The results suggest that in chronic renal failure, platelet function is normal until serum creatinine exceeds 6 mg/100 ml and thereafter progressively deteriorates. Improvement is not obtained by 12 m2 hours of hospital dialysis but is by 18 m2 hours per week of home dialysis. Platelet function studies may be of value in assessing the adequacy of dialysis.     

Changes in intestinal flora and its correlation with renal function in chronic renal failure patients

Objective To investigate changes in intestinal bacteria in chronic renal failure (CRF), their diagnostic value for CRF, and correlations between specific bacterial genera and renal function. Methods Fecal specimens were collected from 56 patients with CRF and 38 healthy controls in the Nephrology Department and Medical Examination Center of Shanxi People's Hospital between August 2017 and January 2018. High-throughput sequencing analysis of 16S rDNA V3-V4 hypervariable regions was performed for intestinal bacteria. Intestinal bacteria in CRF patients and healthy subjects were analyzed for alpha, beta diversity, species composition analysis, and differential species analysis. The diagnostic value of the presence of specific intestinal bacteria for CRF was analyzed using a receiver operating characteristic curve (ROC). Pearson's correlation analysis was used to analyze the correlation between the presence of specific genera and the estimated glomerular filtration rate (eGFR). Results The alpha and beta diversity in the CRF group was different from that in the control group (P﹤0.05). At the phylum level, Verrucomicrobia were significantly less abundant in the CRF group than that in the control group (0.70% vs 3.09%, P﹤0.001). The abundance of Actinobacteria was significantly greater in the CRF group than that in the control group (1.48% vs 1.14%, P=0.036). At the genus level, the abundance of Akkermansia (0.96% vs 3.90%), Parasutterella (0.47% vs 0.93%), and Lactobacillus (0.07% vs 0.48%) in the CRF group was significantly less than those in the control group (all P﹤0.01). The abundance of Alloprevotella (0.41% vs 0.04%) and Clostridium IV (0.6% vs 0.1%) was significantly greater than those in the control group (all P﹤0.05). The diagnostic value of CRF for the area under the ROC curve (AUC) for Akkermansia was 0.753, and that for Lactobacillus diagnostic value of CRF was 0.792. The combined AUC diagnostic value of CRF for detection of Akkermansia and Lactobacillus was 0.830, with high disease prediction value. Lactobacillus abundance was positively correlated with eGFR (R=0.29, P=0.029). Conclusions The diversity and structure of intestinal bacteria are altered in patients with CRF. The abundance of Akkermansia and Lactobacillus has diagnostic value for CRF. The abundance of Lactobacillus is positively correlated with eGFR.     

慢性肾功能衰竭患者的高同型半胱氨酸血症

目的 研究慢性肾功能衰竭（ＣＲＦ）患者血浆同型半胱氨酸（Ｈｃｙ）水平、影响因素以及与心、脑血管疾病的关系。方法 采用荧光偏振免疫分析法测定１６０例ＣＲＦ患者血浆总同型半胱氨酸（ｔＨｃｙ）水平，以３１例冠心病患者和４５例正常人为对照。结果 以正常组血浆ｔＨｃｙｘ±２ｓ为９５％可信度上限，ＣＲＦ患者高同型半胱氨酸血症的发生率为８２．５０％，明显高于冠心病组（２２．５８％）（Ｐ＜０．０１）；血液透析（ＨＤ）组血浆ｔＨｅｙ水平［（２４．１３±１２．６８）μｍｏｌ／Ｌ，ｎ＝７３］明显高于持续性非卧床腹膜透析（ＣＡＰＤ）组［（１６．４３ ±５．５８）μｍｏｌ／Ｌ，ｎ＝１９］、冠心病组［（１１．１３±４．９７）μｍｏｌ／Ｌ，ｎ＝３１］以及正常组（７．９７±２．６５）μｍｏｌ／Ｌ，ｎ＝４５，Ｐ均＜０．０１。９２例透析治疗的ＣＲＦ患者中有明确心、脑血管病者的血浆ｔＨｃｙ水平［（２７．１２±１５．９４）μｍｏｌ／Ｌ，ｎ＝３０］明显高于无此类病史的患者［（２０．１７±８．７１）μｍｏｌ／Ｌ，ｎ＝６２］。未经透析的 ＣＲＦ患者血浆 ｔＨｃｙ水平与内生肌酐清除率呈负相关（ｒ＝－０．３７４，Ｐ＜０．０１），与患者年龄、血葡萄糖、血脂及血浆白     

Zinc in patients with chronic renal failure

In order to assess zinc status in patients with chronic renal failure (CRF) plasma and erythrocyte zinc levels were determined in 13 patients undergoing regular haemodialysis. Additional determinations of plasma copper, plasma and erythrocyte magnesium and potassium were also performed. The mean plasma zinc level was slightly less than normal, but the difference was not statistically significant. The erythrocyte zinc content, however, as well as erythrocyte magnesium and potassium levels were significantly increased (p<0.001). This increase may be partly related to haemolysis in uraemia. Plasma copper concentration in CRF patients did not differ significantly from the control level. The almost normal plasma zinc concentration, elevated erythrocyte zinc, and normocupraemia do not indicate zinc deficiency in CRF patients.     

Gastrointestinal function in chronic renal failure

Feeding problems, anorexia and vomiting are common in infants and children with chronic renal failure (CRF), and play a major role in the growth failure often found in this condition. However, the gastroenterological and nutritional aspects of CRF in children have received little attention, hence therapeutic interventions are usually empirical and often ineffective. Gastritis, duodenitis and peptic ulcer are often found in adults with CRF on regular haemodialysis and following renal transplantation. Despite persistent hypergastrinaemia, gastric acid secretion is decreased rather than increased in most of these patients, and active peptic disease appears to be promoted by the removal of the acid output inhibition (neutralisation of gastric acid by ammonia) that follows active treatment.Helicobacter pylori, on the other hand, does not seem to play a significant role in the pathogenesis of peptic disease in CRF. Gastro-oesophageal reflux has been found in about 70% of infants and children with CRF suffering from vomiting and feeding problems, and thus appears to be a major problem in these patients. In a number of symptomatic patients with CRF, gastric dysrhythmias and delaved gastric emptying have also been found; hence there appears to be a complex disorder of gastrointestinal motility in CRF. Serum levels of several polypeptide hormones involved in the modulation of gastrointestinal motility [e.g. gastrin, cholecystokinin (CCK), neurotensin] and the regulation of hunger and satiety (e.g. glucagon, CCK) are significantly raised as a consequence of renal insufficiency, and can be reverted to normal by renal transplantation. Furthermore, several other humoral abnormalities (e.g. hypercalcaemia, hypokalaemia, acidosis, etc.) are not uncommon in CRF. By directly affecting the smooth muscle of the gut or stimulating particular areas within the central nervous system, all these humoral alterations may well play a major role in the gastrointestinal dysmotility, anorexia, nausea and vomiting in patients with CRF. Specific pharmacological and nutritional interventions should thus be considered for the treatment of vomiting and feeding problems in CRF.     

Bromocriptine and the hypothalamic hypophyseal function in patients with chronic renal failure on chronic hemodialysis

Ten patients with chronic renal failure on chronic hemodialysis had the following tests to evaluate the integrity of the hypothalamic hypophyseal axis: (A) glucose tolerance test, (B) thyrotropin releasing hormone stimulation test, (C) clonidine stimulation test, (D) insulin induced hypoglycemia, and (E) LH/RH stimulation test. The majority of those tests were abnormal and prolactin values were found to be moderately elevated in all the patients. Bromocriptine (1.25 mg twice a day) was given to all the patients for 1 month and then, while on bromocriptine, the tests were repeated. Although there is a decrement in the concentration of serum prolactin level, none of the hypothalamic hypophyseal abnormalities were corrected. However, five of the ten patients reported an improvement of their impotence with bromocriptine. The patients who responded had high levels of FSH and LH with levels of testosterone above 1 mg/mL. The nonresponders had low FSH and LH levels and very low testosterone levels. Therefore, bromocriptine, although possibly beneficial in some dialysis patients, is not a drug that can normalize abnormal functioning of hormones in the dialysis population.     

慢性肾功能衰竭患者肾移植术前肺功能的变化

目的 探讨慢性肾功能患者肾移植术前肺功能情况。方法：选择术前行血液透析的慢性肾功能衰竭患者２１例,分别测定肺容量、肺通气功能、小气道功能及弥散功能,测定结果以实测值占预计值的百分比来表达,并分别对肺功能损害情况作百分比统计。结果 ２１例患者肺功能的改变以弥散功能障碍为主,其次为小气道阻塞和轻度肺气肿。结论 慢性肾功能衰竭患者肾移植术前肺功能检查对术后呼吸监护有一定的参考价值,建立将肺功能检查列为肾     

Residual kidney function and plasma urea concentration in patients with chronic renal failure

The relationships between the plasma levels of urea (P_urea), renal clearance of urea (C_urea) and creatinine (C_cr) at an intake of 0.5 g protein/kg body weight/day were followed in 10 patients with chronic renal failure (CRF) under balance conditions. Under these conditions, P_urea attained a value of 30 mmol/l when C_urea had decreased below 3.8 ml/min. By contrast, no correlation could be demonstrated between P_urea and C_cr under these conditions. The same relationships were followed in another group of 30 outpatients with CRF. Even in patients not followed under balance conditions, C_urea determination makes it possible to establish whether the high increase in P_urea is due to the decrease in residual renal function below the critical level or whether extrarenal factors are involved. Likewise, no significant correlation between P_urea and C_cr could be demonstrated under these conditions. The findings suggest that C_urea measurement in CRF patients helps to assess residual renal function in terms of P_urea regulation and provides information that cannot be obtained by C_cr measurement.     

Calcium infusion and left ventricular diastolic function in patients with chronic renal failure

Background. Left ventricular (LV) function is sensitive to disorders in calcium metabolism. Most previous reports have focused on the effects of calcium on systolic performance. We studied the acute effect of calcium infusion on LF diastolic function in patients with moderate to severe chronic renal failure (CRF) and secondary hyperparathyroidism (SHP). Methods. We infused calcium gluconate at a constant rate of 45 &mgr;mol/kg/h to 14 patients with severe to moderate CRF and SHP. Our aim was to reach slightly supranormal levels of serum ionized calcium (1.35-1.45 mmol/l). LV diastolic function was assessed by pulsed Doppler echocardiography before and after the calcium infusion. The echocardiographic indices were compared to those of 14 age- and sex-matched healthy controls. Results. Before calcium infusion the patients had significantly greater LV dimensions than the controls, but there was no differences in the diastolic indices. During calcium infusion, serum ionized calcium increased from 1.18±0.03 to 1.40±0.03 mmol/l (P<0.0001) and plasma intact PTH decreased from 38.6±5.6 to 9.0±2.2 pmol/l (P<0.0001). Calcium infusion did not affect the LV dimensions or fractional shortening. The peak early diastolic velocity (Emax) decreased and peak late diastolic velocity (Amax) increased, and their relationship decreased significantly (1.552±0.586 vs 1.414±0.535 m/s, P=0.03). These changes reflect impairment of LV diastolic function. Conclusions. Induction of acute hypercalcaemia by calcium infusion impairs LV diastolic function in patients with CRF and SHP.     

Skeletal muscle mitochondrial function is preserved in young patients with chronic renal failure

Patients with chronic renal failure (CRF) show limited exercise tolerance, classically attributed to anemia. However, persistence of abnormally low peak oxygen consumption, even after restoration of hemoglobin concentration with recombinant erythropoietin therapy and studies of muscle bioenergetics, suggests that the problem is located beyond hemoglobin oxygen transport. The present study is designed to assess mitochondrial respiratory chain (MRC) function from skeletal muscle of patients with CRF to determine whether there is impairment in mitochondrial oxidative capacity. We studied six young patients with CRF on regular hemodialysis and erythropoietin therapy and six healthy controls matched by age, sex, anthropometric characteristics, and physical activity. Muscle biopsy of the quadriceps was performed, and mitochondria were isolated. Mitochondrial content was estimated by means of mitochondrial yield and citrate synthase activity. Maximal capacity for oxygen consumption was measured polarographically using complex I, II, III, and IV substrates of the MRC. Individual enzyme activities of MRC complexes I to V were determined spectrophotometrically. Membrane lipid peroxidation was estimated by cis-parinaric fluorescence. Compared with controls, patients with CRF showed preserved mitochondrial content, conserved respiratory activity, intact enzyme activity of MRC complexes, and no increase in lipid peroxidation. We therefore conclude that mitochondrial function is preserved in young patients with CRF. © 2002 by the National Kidney Foundation, Inc.     

Hip arthroplasty in patients with chronic renal failure

Patients with chronic renal failure who underwent total hip arthroplasty were retrospectively evaluated. Thirty hips in patients with renal transplants and 16 hips in patients on chronic renal dialysis were reviewed. The average follow-up period was 54 months. The renal transplant patients exhibited generally satisfactory results. Their postoperative course was comparable to that of patients with avascular necrosis undergoing hip reconstruction without underlying renal disease. However, patients undergoing hip arthroplasty while on chronic renal dialysis had poor results (81%), including a deep infection rate of 19%. It was concluded that total hip arthroplasty be reserved for patients who are expecting a renal transplant or preferably for those who have already received a successful transplant.     

Energy expenditure in patients with chronic renal failure

Although nondialyzed, chronically uremic patients and patients undergoing maintenance hemodialysis often show evidence for wasting and calorie malnutrition and have low dietary energy intakes, their energy expenditure has never been systematically evaluated. It is possible that low energy intakes are an adaptive response to reduced energy needs; alternatively, energy expenditure could be normal or high and the low energy intakes would be inappropriate. Energy expenditure was therefore measured by indirect calorimetry in 12 normal individuals, 10 nondialyzed patients with chronic renal failure, and 16 patients undergoing maintenance hemodialysis. Energy expenditure was measured in the resting state, during quiet sitting, during controlled exercise on an exercise bicycle, and for four hours after ingestion of a test meal. Resting energy expenditure (kcal/min/1.73 m2) in the normal subjects, chronically uremic patients and hemodialysis patients was, respectively, 0.94 +/- 0.24 (SD), 0.91 +/- 0.20, and 0.97 +/- 0.10. There was also no difference among the three groups in energy expenditure during sitting, exercise, or the postprandial state. Within each group, energy expenditure during resting and sitting was directly correlated. During bicycling, energy expenditure was directly correlated with work performed, and the regression equation for this relationship was similar in each of the three groups. These findings suggest that for a given physical activity, energy expenditure in nondialyzed, chronically uremic patients and maintenance hemodialysis patients is not different from normal. The low energy intakes of many of these patients may be inadequate for their needs.