Kidney transplantation improves arterial stiffness in patients with end-stage renal disease

Background

Cardiovascular disease (CVD) is the leading cause of mortality among the patients with end-stage renal disease (ESRD). Arterial stiffness is a well-accepted predictor of cardiovascular mortality in general population and ESRD patients. The aim of this study was to compare the change of arterial stiffness in kidney transplant recipients (KTRs) and ESRD patients, and further investigate the impact of kidney transplantation (KT) on arterial stiffness.

Methods

A total of 138 maintenance hemodialysis patients, 198 KTRs and 75 healthy volunteers were enrolled in this study. The carotid-femoral pulse wave velocity (CF-PWV) and carotid-radial PWV (CR-PWV) were determined, and the correlations of PWV with biochemical parameters were analyzed.

Results

CF-PWV was highest in the maintenance hemodialysis patients, but similar between KTRs and healthy volunteers. Bivariate correlation analysis among KTRs demonstrated that CF-PWV was positively correlated with high level of peripheral diastolic blood pressure, pulse pressure, mean artery pressure, BUN and HDL, but negatively correlated with albumin. Univariate polytomous logistic regression analysis showed that age, BMI, systolic blood pressure, pulse pressure, length of KT and BUN were associated with the increase of CF-PWV value.

Conclusions

Aortic stiffness could be improved after KT. Meanwhile, age, BMI, systolic blood pressure, pulse pressure, length of KT and BUN were independent predictors of the increase of CF-PWV in KTRs.

     

Is oxidative stress implicated in high bone turnover in end-stage renal disease (ESRD)?

Sir, End stage renal disease (ESRD) is a condition in which oxidativestress is much enhanced and implicated in a variety of uremiccomplications [1,2]. Oxidative stress influences bone turnover     

Erectile function in end-stage renal disease before and after renal transplantation

INTRODUCTION: Erectile function in end-stage renal disease (ESRD) and renal transplant patients is a challenging issue. In this study we evaluated the prevalence of erectile dysfunction (ED) according to standard questionnaires and paraclinical tests including Rigiscan. MATERIALS AND METHODS: We conducted a prospective, interventional, nonrandomized study of 15 consecutive male patients who underwent living donor renal transplants from March 2003 to June 2004. Before and after living donor transplantation we did hormone assays, blood ionogram and biochemistry, complete blood counts, u/a, international index of erection function 5 (IIEF-5), erection dysfunction intensive score (EDIS) tests as well as Rigiscan. RESULTS: The patient ages were between 21 and 50 (average 35.26) years, with an average length of ESRD of 4.31 years. Of the patients, 73.33% were smokers; 46.66% had ED; and 40%, hypertension. The most common blood groups were B-positive and O-positive (33.3% each). Mean testosterone and prolactin levels showed significant decreases after renal transplantation (P = .001 and P = .005, respectively). Mean blood glucose also decreased significantly (P = .035), despite previous reports that immunosuppressive drugs cause pseudodiabetes mellitus, mean cholesterol and triglyceride levels decreased after renal transplantation (P = .013, P = .0668, respectively). Urinalysis did not differ significantly after renal transplantation. Mean urea and creatinine levels were decreased significantly by renal transplantation (P = .000 and P = .003, respectively), but neither the mean values of uric acid nor the blood cell count were significantly different (P = .374). Mean hemoglobin and hematocrit levels were increased by renal transplantation, but it was not significant (P = .297 and P = .187, respectively). Mean potassium and phosphorus level were significantly decreased (P = .049 and P = .047, respectively), but mean sodium and calcium levels were not significantly altered (P = .773 and P = .536, respectively). Mean total and direct bilirubin and liver enzymes and alkaline phosphatase and LDH also did not change significantly. IIEF-5 was improved in 11 cases, unchanged in two cases, and worsened in another two cases. Nocturnal penile tumescence (Rigiscan test) was also improved in 11 cases, unchanged in three cases, and worsened in one case. The prevalence of erectile function was increased according to the EDIS question. CONCLUSION: Erectile function was improved after successful live donor renal transplant.     

Hyperleptinaemia of end-stage renal disease is corrected by renal transplantation

Background: Previous studies have reported that patients with end-stage renal disease (ESRD) have elevated plasma leptin concentrations, but the cause and significance of the elevations are unknown. We studied leptin concentrations in 29 adults undergoing renal transplantation, to determine if restoration of renal function reduced leptin concentrations in ESRD. Methods: Leptin concentrations were measured by radioimmunoassay in plasma specimens collected within 1 week before transplant, 6 days post-transplant, and 60 days post-transplant. Results: Plasma letpin concentrations were higher in both male and female ESRD patients compared with a control population of similar age and body mass index (BMI), but most of the disparity was due to a minority of patients with grossly elevated concentrations; the majority of ESRD patients had normal or near-normal leptin concentrations afer accounting for their adiposity with BMI. Six days after successful renal transplantation, average plasma leptin concentrations decreased to control levels. The grossly elevated pretransplant concentrations in a minority of patients were greatly reduced in relation to BMI, and the reduction persisted to 60 days post-transplant. The decrease in creatinine with transplant did not correlate with the decrease in leptin. Conclusions: These results demonstrate that restoration of renal function in ESRD patients reduces hyperleptinaemia, which provides further evidence of a cause/effect relationship between impaired renal function and abnormal leptin metabolism.      

Arterial calcifications and bone histomorphometry in end-stage renal disease

Arterial calcification (AC) is a common complication of end-stage renal disease (ESRD). The mechanisms responsible are complex, including disturbances of mineral metabolism and active expression of various mineral-regulating proteins. An inverse relationship between AC and bone density has been documented in uremic patients. In the study presented here, which included 58 patients with ESRD on hemodialysis (HD), bone-histomorphometry characteristics were compared with the AC scores (0 to 4) determined according to the number of arterial sites with calcifications. Patients with AC scores of 0 (no calcifications), or 1 or 2 (mild calcifications) had similar serum parathyroid hormone levels and bone histomorphometry, with larger osteoclast resorption, higher osteoclast numbers, and larger osteoblastic and double tertracycline-labeled surfaces. In contrast, patients with high AC scores (3 and 4) were characterized by lower serum parathyroid hormone, low osteoclast numbers and osteoblastic surfaces, smaller or absent double tetracycline-labeled surfaces, and high percentages of aluminum-stained surfaces. According to multivariate analysis, AC score was positively associated with age (P < 0.0001), daily dose of calcium-containing phosphate binders (P = 0.009), and bone aluminum-stained surfaces (P = 0.037), and an inverse correlation was observed with osteoblastic surfaces (P = 0.001). A high AC score is associated with bone histomorphometry suggestive of low bone activity and adynamic bone disease. These findings suggest that therapeutic interventions associated with excessive lowering of parathyroid activity (parathyroidectomy, excessive calcium or aluminum load) favor lower bone turnover and adynamic bone disease, which could influence the development and progression of AC.     

Differences in bone turnover and intact PTH levels between African American and Caucasian patients with end-stage renal disease

BACKGROUND: Evidence derived from healthy subjects suggests that African Americans have higher serum parathyroid hormone (PTH) levels and decreased bone responsiveness to PTH than Caucasians. African American patients with end-stage renal disease (ESRD) also have higher serum PTH than Caucasians. Studies that correlate intact PTH (iPTH) levels with bone turnover in ESRD patients were performed in a predominantly Caucasian population. METHODS: In this study, serum iPTH and bone histomorphometric data were analyzed for racial differences in 76 ESRD patients (Caucasian = 48, African Americans = 28). Bone turnover was determined by histomorphometric measurement of activation frequency in all patients. RESULTS: Age, duration of dialysis, and calcium and phosphorus levels were similar between the two groups. iPTH levels (pg/mL; mean +/- SE) were significantly higher in the African American group (534 +/- 79 vs. 270 +/- 46, P < 0.01). Also, alkaline phosphatase levels (IU/L) were significantly higher in the African American group (162 +/- 31 vs. 144 +/- 43, P < 0.01). Correlations between PTH levels and activation frequency were r = 0.60, P < 0.01 in Caucasians and r = 0.22, P = NS in African Americans. The mean PTH level in African American patients with histologic findings of low bone turnover was 460 +/- 115 vs. 168 +/- 41 in Caucasian patients with similar bone turnover (P < 0.01). In patients with low bone turnover, African Americans had significantly higher osteoid volume and thickness, number of osteoblasts and osteoclasts, erosion surface, peritrabecular fibrosis, and single-label surface than Caucasians. However, erosion depth, bone formation rate per osteoblast and mineralization apposition rate were similar between the two groups. CONCLUSION: There is no correlation between iPTH and bone turnover in African Americans with ESRD. A substantial number of African American patients with low bone turnover have very high serum PTH levels. Bone histomorphometric results reveal differences in remodeling dynamics and responses to PTH between African American and Caucasian patients. Further studies utilizing newer PTH measurement assays are needed to better delineate the correlation between PTH and bone turnover in the various racial groups.     

Disturbances of acid-base balance and bone disease in end-stage renal disease

Bone disease in patients with chronic renal failure (CRF) is thought to be the consequence primarily of the interplay of several factors, including the serum levels of parathyroid hormone (PTH), vitamin D, calcium, and phosphorus, and exposure to bone toxins such as aluminum or amyloid. Recently the metabolic acidosis noted with CRF has been implicated as an additional factor contributing to the genesis of bone disease. Although metabolic acidosis might be the dominant factor in the cause of bone disease in some instances, more commonly this acid-base disturbance interacts with other factors contributing to the development of bone disease. The following article summarizes the data in support of an important role for metabolic acidosis in the genesis of bone disease in patients with CRF and presents our recommendations for treatment of uremic acidosis to prevent or treat the bone disease.     

Which bone age in chronic renal insufficiency and end-stage renal disease?

One hundred radiographs of the left hand and wrist from 40 children with chronic renal insufficiency or end-stage renal disease were examined to determine which method of bone age estimation provided the most useful information in these children. The Tanner and Whitehouse method showed better repeatability than the Greulich and Pyle atlas or the Buckler handbook when a sample of the radiographs were assessed twice by the same observer. The Tanner and Witehouse 20 (TW20) bone age showed less inter-observer bias than the radius, ulna and short bone age or the carpal bone age when three observers independently assessed the same sample of radiographs. TW20 was the most useful method of bone age assessment in this study of British children. An unexpected finding was that the carpal bones were significantly more retarded than the radius, ulna and short bones. Separate assessment of the carpal bone age may provide extra information of clinical relevance.     

Pathogenesis and management of hyperparathyroidism in end-stage renal disease and after renal transplantation

SUMMARY: Secondary hyperparathyroidism is an adaptive response to progressive loss of renal function so as to maintain calcium and phosphate homeostasis, 1,25-dihydroxyvitamin D₃ levels and normal bone turnover, despite skeletal resistance to parathyroid hormone. As feedback regulation fails, complications of parathyroid overactivity develop, and by the commencement of dialysis abnormal bone histology is present in almost all patients, with hyperparathyroid changes most commonly found. Post transplantation, persisting hyperparathyroidism predisposes to osteoporosis. The risk of bone disease is reduced by early, carefully targeted dietary measures and suppressive therapy with calcitriol and calcium-based phosphate binders, while newer therapies include bisphosphonates and calcimimetics. Timely surgical intervention is necessary in some patients.     

Successful kidney transplantation ameliorates arterial stiffness in end-stage renal disease patients

Purpose

Successful kidney transplantation (KTx) can ameliorate bodily damage caused by end-stage renal disease (ESRD). Arterial stiffness (AS) is one of the critical factors that shorten the survival of patients due to cardiovascular events. KTx may reduce AS as well; however, this has not been investigated well. We therefore conducted a retrospective study using noninvasive pulse wave velocity (PWV), which is a useful index of aortic damage.

Patients and methods

Fifty-eight consecutive kidney recipients (34 men, 24 women) were enrolled in this study. Mean age at transplantation was 40.5 ± 12.3 years and the dialysis period was 73.1 ± 95.8 months. The brachial-ankle PWV was measured preoperatively and 6 months postoperatively. First, we investigated the relationship between the PWV and the other parameters related to AS. Second, we studied the pre- to posttransplant change in PWV to evaluate the amelioration of AS after successful KTx.

Results

PWV showed significant positive correlations with age, systolic blood pressure (BP), diastolic BP, and abdominal aortic calcification index. After successful KTx, PWV significantly decreased (P < .01). In addition, systolic and diastolic BP significantly decreased (P < .01 and P < .05, respectively).

Conclusion

Successful KTx ameliorates AS in ESRD patients. This might explain the improved cardiovascular prognosis of ESRD patients who undergo KTx.     

Living related renal transplantation for end-stage renal disease after liver transplantation from a brain-dead donor

We report a case in which a living related renal transplantation was successfully performed for end-stage renal disease that had progressed after a liver transplantation from a brain-dead donor for liver cirrhosis associated with type C hepatitis. Because the transplanted liver function had been excellent with the use of tacrolimus and mycophenolate mofetil, the same immunosuppressive agents with prednisolone were employed for the renal transplantation. Both grafts are functioning well without recurrence of hepatitis at 10 months after the renal transplantation. From our experience, renal transplantation should not be contraindicated even if the patient has undergone liver transplantation or has hepatitis C viral infection.     

Comparison of renal transplantation and dialysis in rehabilitation of diabetic end-stage renal disease patients

We have reviewed the outcome of replacement therapy for end-stage renal disease (ESRD) in 100 diabetic patients with emphasis on late complications, extrarenal diabetic manifestations, and overall patient rehabilitation. Long-term complications, other than myocardial infarction, were not different after renal transplantation compared with chronic dialysis. Overall rehabilitation was better after renal transplantation compared with chronic dialysis (p less than 0.05). Retinopathy and neuropathy were more stable with renal transplantation and peritoneal dialysis compared with hemodialysis (p less than 0.05). These factors should be considered along with expected patient survival when deciding between different treatment modalities for diabetic ESRD.     

A distinct bone phenotype in ADPKD patients with end-stage renal disease

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