Compliance with mineral metabolism targets in haemodialysis patients: moving backwards?

BACKGROUND: To standardize therapy and improve the clinical outcome for chronic haemodialysis (HD) patients, guidelines have been developed for mineral metabolism management. We evaluated compliance with different mineral metabolism guidelines. METHODS: 2,951 chronic HD patients from 61 dialysis centres in Spain were studied. Mineral metabolism management data from a 1-year period were analysed according to KDOQI, KDIGO, and Spanish guidelines. RESULTS: Only 1% (KDOQI), 6% (KDIGO) and 11% (Spanish guidelines) of patients continuously achieved total calcium (Ca), phosphate (P) and parathyroid hormone (PTH) target-range values during the year with higher percentages if we considered the 1-year average. The yearly Ca, P and iPTH average accomplished Spanish guidelines with different percentage among centres: CA 62-100%, P 59-91%, PTH 61-89%, and 28-77% considering all three targets together. The KDIGO guidelines recommend similar percentages except for P (33-77%). No differences were found related to eKt/V, online haemodiafiltration/HD, weight, body mass index, or dialysis vintage. They were only related to age, blood flow, effective treatment time, and dialysate calcium but without relevant clinical differences. Patients outside the target ranges generated significantly higher treatment costs. CONCLUSIONS: Compliance with mineral metabolism targets in HD patients was poor and showed a wide variation between treatment centres.

Economic impact of vitamin D treatment on chronic kidney disease patients.

During recent years, increasing recognition has been given to the endocrine action that vitamin D has on the extraskeletal system, and its deep involvement in CKD. This has meant that many vitamin D compounds (both nutritional and active) have been made available, with an important cost reduction. This review looks at the evidence available regarding the usefulness of different types of vitamin D (nutritional and active) for patients with stage 3-5 CKD and those undergoing dialysis. Emphasis is given to its usefulness to control hyperparathyroidism and its impact on morbidity and mortality. We also analysed pharmacoeconomic studies that have been published which compare active vitamin D metabolites. From this review, we are able to conclude that there is still not enough scientific evidence to be able to prefer one active vitamin D over another. In the meantime, doctors should follow the recommendations given in clinical practice guidelines, always taking into account their personal experience with patients. Furthermore, they must consider the economic impact that their treatment decisions may have.

Assessment of glomerular filtration rate in transplant recipients with severe renal insufficiency by Nankivell, Modification of Diet in Renal Disease (MDRD), and Cockroft-Gault equations.

Measurement of glomerular filtration rate (GFR) is time consuming and cumbersome. Several formulas have been developed to predict creatinine clearance (CrCl) or GFR using serum creatinine (Cr) concentrations and demographic characteristics. However, few studies have been performed to discern the best formula to estimate GFR in kidney transplantation. In this study, Cockroft-Gault (CG), Nankivell, and Levey (MDRD) formulas were tested to predict GFR in 125 cadaveric renal transplant patients with severe renal insufficiency (GFR less than 30 mL/min per 1.73 m2). The GFR was estimated as the average Cr and urea clearances. The mean GFR estimated by averaged Cr and urea clearances (22.18+/-5.23 mL/min per 1.73 m2) was significantly different from the mean values yielded by the MDRD formula (20.42+/-6.65 mL/min per 1.73 m2, P=.000), the Nankivell formula (30.14+/-11.98 mL/min per 1.73 m2, P=.000), and the CG formula (29.42+/-8.64 mL/min per 1.73 m2, P=.000). The MDRD formula showed a better correlation (R=0.741, P=.000) than the CG (R=0.698, P=.000) and the Nankivell formulas (R=0.685, P=.000). Analysis of differences using the Bland-Altmann method demonstrated that MDRD gave the lowest bias (MDRD: -1.65+/-4.4 mL/min per 1.73 m2; CG: 7.33+/-6.24 mL/min per 1.73 m2; Nankivell: 8.05+/-9.23 mL/min per 1.73 m2) and narrower limits of agreement (Nankivell: -10.41-26.51 mL/min per 1.73 m2; CG: -5.15-19.81 mL/min per 1.73 m2; MDRD: -10.61-7.31 mL/min per 1.73 m2). In transplant patients with severe renal insufficiency, the MDRD equation seems better than the other formulas to estimate GFR.

["Occult" renal insufficiency due to evaluating renal function using only serum creatinine]. / Insuficiencia renal "oculta" por valoración de la función renal mediante la creatinina sérica.

Timely referral to nephrologists depends on identification of renal failure. Most primary care physicians and specialists rely on serum creatinine as the standard test for determination of renal function. Creatinine clearance requires 24 hours urine collection with many pitfalls and wrong results. We compare serum creatinine and the Cockcroft-Gault (C-G) equation as measure of glomerular filtration rate (GFR). The study included 1,053 outpatients with serum creatinine lower than 2.5 mg/dl referred to our nephrological laboratory for serum creatinine and GFR determination using the C-G formula. Patients were grouped into two groups: normal renal function (serum creatinine < 1.3 mg/dl) and "incipient" abnormal renal function (serum creatinine 1.3-2.5 mg/dl). In the group of females with normal creatinine 22% (60-70 y), 35% (70-80 y) and 57% (> 80 y) had GFR values below 50 ml/min. In the group of males 11.3% (70-80 y) and 33.3% (> 80 y) also had GFR reduction in spite of normal serum creatinine. A severe renal insufficiency with creatinine clearance lower than 30 ml/min was observed in the group with "incipient" renal failure based on serum creatinine: 22.7%, 40% and 82.9% for females and 6%, 22.7% and 57% for male (60-70 y; 70-80 y; and > 80 y respectively). In order to improve management and prevention of renal failure appropriate measurements of renal function other than serum creatinine should be emphasize.