Vegetarian diet may ameliorate uremic pruritus in hemodialysis patients

Objectives: Systemic inflammation has been reported to be associated with uremic pruritus (UP). Although a vegetarian diet can reduce systemic inflammation in hemodialysis patients, the effect of vegetarian diet on UP is not clear. The purpose of the study was to know the possible effects of vegetarian diet on UP.

Methods: A cross-sectional study was done to compare the severity of UP and blood levels of systemic inflammatory markers between vegetarian and non-vegetarian hemodialysis patients. Six non-vegetarian patients with uremic pruritus changed their non-vegetarian diet to vegetarian diet for 2 months. Visual Analogue Scale (VAS) and pruritus score (PS) were used to measure the UP severity. The serum high-sensitivity C-reactive protein (hs-CRP), and interleukin-2 (IL-2) were used as markers of inflammation.

Results: Both the median VAS scores (p = .043) and the median PS scores (p < .001) were lower in the Vegetarian than in the non-vegetarian group. The median values of hs-CRP in Vegetarian were lower than that for the non-vegetarian (p = .020). The median value of IL-2 was also lower in Vegetarian than that of the non-vegetarian (p = .016). There were 6 non-vegetarian patients shift to vegetarian for 2 months. The pruritus score improved and IL-2 level decreased after change to vegetarian diet.

Conclusion: We concluded that vegetarian diet might be associated with the amelioration of the uremic pruritus severity in hemodialysis patients.

Serum PTH reference values established by an automated third-generation assay in vitamin D-replete subjects with normal renal function: consequences of diagnosing primary hyperparathyroidism and the classification of dialysis patients

OBJECTIVE

To determine parathyroid hormone (PTH) reference values in French healthy adults, taking into account serum 25-hydroxyvitamin D (25OHD), renal function, age, gender, and BMI.

PARTICIPANTS AND MAIN BIOLOGICAL MEASUREMENTS

We studied 898 healthy subjects (432 women) aged 18-89 years with a normal BMI and estimated glomerular filtration rate (eGFR), 81 patients with surgically proven primary hyperparathyroidism (PHPT), and 264 dialysis patients. 25OHD and third-generation PTH assays were implemented on the LIAISON XL platform.

RESULTS

Median PTH and 25OHD values in the 898 healthy subjects were 18.8  ng/l and 23.6  ng/ml respectively. PTH was lower in subjects with 25OHD ≥30  ng/ml than in those with lower values. Among the 183 subjects with 25OHD ≥30  ng/ml, those aged ≥60 years (n=31) had higher PTH values than younger subjects, independent of 25OHD, BMI, and eGFR (P<0.001). Given the small number of subjects aged ≥60 years, we adopted the 95% CI of PTH values for the entire group of 183 vitamin D-replete subjects (9.4-28.9  ng/l) as our reference values. With 28.9  ng/l as the upper limit of normal (ULN) rather than the manufacturer's ULN of 38.4  ng/l, the percentage of PHPT patients with 'high' PTH values rose to 90.1% from 66.6% (P<0.001), and 18.6% of the dialysis patients were classified differently in view of the KDIGO target range (two to nine times the ULN).

CONCLUSION

When only subjects with 25OHD ≥30  ng/ml were included in the reference population, the PTH ULN fell by 22.4%, diagnostic sensitivity for PHPT improved, and the classification of dialysis patients was modified.

Government Quality Measures: First Do No Harm

A technical expert panel (TEP) was convened to evaluate all available literature in the area of bone and mineral metabolism and advise the Centers for Medicare and Medicaid services on the creation and collection of quality measures. The proposed quality measures were evaluated for importance, usability, feasibility, and scientific acceptability. All are important parameters to avoid unintended harmful consequences of a quality measure causing harm to patients or to the delivery of their health care.

Growth retardation in children with kidney disease

Growth failure is almost inextricably linked with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Growth failure in CKD has been associated with both increased morbidity and mortality. Growth failure in the setting of kidney disease is multifactorial and is related to poor nutritional status as well as comorbidities, such as anemia, bone and mineral disorders, and alterations in hormonal responses, as well as to aspects of treatment such as steroid exposure. This review covers updated management of growth failure in these children including adequate nutrition, treatment of metabolic alterations, and early administration of recombinant human growth hormone (GH).

Variation in parathyroid hormone immunoassay results--a critical governance issue in the management of chronic kidney disease

Renal physicians strive to maintain parathyroid hormone (PTH) concentrations for patients with chronic kidney disease (CKD) within guideline limits, but poor method comparability means there is currently serious risk of clinical misclassification. The potential for under- or over-treatment is significant, representing a major challenge to patient safety. In the short-term, raising awareness of clinical implications of method-related differences in PTH is essential. Agreeing and adopting assay-specific PTH action limits for CKD patients as an interim measure is highly desirable and has been achieved in Scotland. Establishing pre-analytical requirements for PTH is also a priority. In the longer term, re-standardization of PTH methods in terms of an appropriate International Standard is required. Provided commutability can be demonstrated, the recently established IS 95/646 for PTH (1-84) is a suitable candidate. Establishment of a well-characterized panel of samples of defined clinical provenance to enable manufacturers to determine appropriate reference intervals and clinical decision points is also recommended and will provide an invaluable clinical resource. Recent developments in mass spectrometry mean that a candidate reference measurement procedure for PTH is now achievable and will represent major progress. Concurrently, evidence-based recommendations on clinical requirements and performance goals for PTH are required. Improving the comparability of PTH results requires support from many stakeholders but is achievable.

Parathyroid hormone measurement in chronic kidney disease--an evolving issue for the nephrologist and the clinical laboratorist: minireview

Parathyroid hormone (PTH) is the polypeptide hormone produced by the parathyroid glands, which plays a central role in calcium homeostasis. Circulating PTH must be measured regularly in patients with chronic kidney disease (CKD)--mineral and bone disorders (MBD) to monitor and to adapt treatment with the aim of maintaining PTH levels within a defined narrow range of optimal values for each stage of CKD. Often, for the nephrologists, it is not easy to determine what PTH levels are clinically appropriate. Moreover, the PTH determination also shows many criticisms from the laboratory point of view and there is a clear need to standardize PTH measurements in every phase of the process: pre-analytical, analytical and post-analytical. In this review, all these aspects are summarized with particular reference to the most recent opportunities to improve PTH assays quality on the whole. To this aim, a closer cooperation between nephrologists and clinical laboratories is undoubtedly necessary.

[Questions about the ADVANCE study]

The symptoms of secondary hyperparathyroidism (SHPT) were substantially changed by the availability of cinacalcet (CC). The recent ADVANCE study, which was a prospective randomized trial comparing two treatment strategies-CC plus low doses of calcitriol analogues (CA) versus higher doses of CA without CC-reports the absence of difference in the primary endpoint, i.e. coronary artery calcification score progression after 12 months. The progression of coronary calcification was related to the initial hypercalcemia and hyperphosphataemia, and low serum PTH level. What was the rationale for defining SHPT with only serum PTH value of more than 300 pg/mL or more than 150 pg/mL associated with a high Ca×P product? Why was this coronary score chosen as the primary endpoint and why was a seemingly short observational period used? Is it correct to consider all forms of SHPT equivalent in terms of set point, response to conventional treatment, or vascular and bone consequences? Why are the biological values of patients not provided? Were the CAs, dialysate calcium, and PTH assay values really equal? Why were only calcium-based phosphate binders used? The main controversial point of the study was to consider all HPT cases as equivalent and able to be treated by one fixed strategy. Therefore, the nephrologist community should conduct relevant independent studies in order to improve the diagnosis and treatment of SHPT.

Endorsement of the Kidney Disease Improving Global Outcomes (KDIGO) Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) Guidelines: a European Renal Best Practice (ERBP) commentary statement

Under the auspices of the European Renal Best Practice, a group of European nephrologists, not serving on the Kidney Disease Improving Global Outcomes (KDIGO) working group, but with significant clinical and research interests and expertise in these areas, was invited to examine and critique the Chronic Kidney Disease-Mineral and Bone Disorder KDIGO document published in August 2009. The final form of this paper in Nephrology Dialysis Transplantation, as a commentary, not as a position statement, reflects the fact that we have had no more evidence to review, discuss and debate available to us than was available to the KDIGO working group. However, we have felt that we were able to comment on specific areas where we feel that further clinical guidance would be helpful, thereby going beyond the KDIGO position as reflected in their document. This present paper, we hope, will be of most use to the practising kidney specialist and those allied to the clinical team.