Dialysis adequacy indices and body composition in male and female patients on peritoneal dialysis.

OBJECTIVES: Creatinine clearance scaled to body surface area (BSA) and urea KT/V normalized to total body water (TBW) are used as indices for peritoneal dialysis (PD) adequacy. We investigated relationships of indices of dialysis adequacy (including KT/V, KT, clearance, dialysate over plasma concentration ratio) and anthropometric and body composition parameters (BSA, TBW, body mass index (BMI), weight, height, fat mass (FM), and fat-free mass (FFM)) in male and female patients on continuous ambulatory peritoneal dialysis. METHODS: Ninety-nine stable patients (56 males) performed four 24-hr collections of drained dialysate for four dialysis schedules with three daily exchanges of glucose 1.36% and one night exchange of either: 1) glucose 1.36%, 2) glucose 2.27%, 3) glucose 3.86% or 4) icodextrin 7.5%. RESULTS: KT and dialysate over plasma concentration ratio, CD/CP, for urea and creatinine were similar for males and females and, in general, did not depend on body-size parameters including V (= TBW), which means that the overall capacity of the transport system in females and males is similar. However, after normalization of KT to V or 1.73/BSA yielding KT/V and creatinine clearance, Cl(1.73/BSA), respectively, the normalized indices were substantially higher in females than in males and correlated inversely with body-size parameters, especially in males. CONCLUSIONS: As KT/V depends strongly on body size, treatment target values for KT/V should take body size and therefore also gender into account. As KT is less influenced by body size, body composition and gender, KT should be considered as a potential auxiliary index in PD.

Cardiovascular and renal effects of bromocriptine in diabetic patients with stage 4 chronic kidney disease.

OBJECTIVE: The objective of this study was to investigate the effect of bromocriptine (BEC) on left ventricular mass index (LVMI) and residual renal function (RRF) in chronic kidney disease (CKD) patients with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: A 6-month double-blind randomized controlled trial was conducted in 28 patients with T2D and stage 4 CKD with increased LVMI. Fourteen patients received BEC (2.5 mg, initially 1 tablet with subsequent increase to three times a day) and 14 received a placebo (PBO; initially 1 tablet with subsequent increase to three times a day). Cardiovascular changes were assessed by monitoring 24 h ambulatory blood pressure, two-dimensional-guided M-mode echocardiography, and N-terminal brain natriuretic peptide (NT-proBNP) plasma levels. RRF was evaluated by creatinine clearance and cystatin-C plasma levels. RESULTS: Both BEC and PBO groups decreased blood pressure-but the effect was more pronounced in the BEC group. Average 24 h, diurnal and nocturnal blood pressures, and circadian profile showed improved values compared to the PBO group; LVMI decreased by 14% in BEC and increased by 8% in PBO group. NT-proBNP decreased in BEC (0.54 ± 0.15 to 0.32 ± 0.17 pg/mL) and increased in PBO (0.37 ± 0.15 to 0.64 ± 0.17 pg/mL). Creatinine clearance did not change in the BEC group and decreased in the PBO group. CONCLUSIONS: BEC resulted in a decrease on blood pressure and LVMI. BEC also prevented the progression of CKD while maintaining the creatinine clearance unchanged.

Threefold peritoneal test of osmotic conductance, ultrafiltration efficiency, and fluid absorption.

BACKGROUND: Fluid removal during peritoneal dialysis depends on modifiable factors such as tonicity of dialysis fluids and intrinsic characteristics of the peritoneal transport barrier and the osmotic agent-for example, osmotic conductance, ultrafiltration efficiency, and peritoneal fluid absorption. The latter parameters cannot be derived from tests of the small-solute transport rate. We here propose a simple test that may provide information about those parameters. METHODS: Volumes and glucose concentrations of drained dialysate obtained with 3 different combinations of glucose-based dialysis fluid (3 exchanges of 1.36% glucose during the day and 1 overnight exchange of either 1.36%, 2.27%, or 3.86% glucose) were measured in 83 continuous ambulatory peritoneal dialysis (CAPD) patients. Linear regression analyses of daily net ultrafiltration in relation to the average dialysate-to-plasma concentration gradient of glucose allowed for an estimation of the osmotic conductance of glucose and the peritoneal fluid absorption rate, and net ultrafiltration in relation to glucose absorption allowed for an estimation of the ultrafiltration effectiveness of glucose. RESULTS: The osmotic conductance of glucose was 0.067 ± 0.042 (milliliters per minute divided by millimoles per milliliter), the ultrafiltration effectiveness of glucose was 16.77 ± 7.97 mL/g of absorbed glucose, and the peritoneal fluid absorption rate was 0.94 ± 0.97 mL/min (if estimated concomitantly with osmotic conductance) or 0.93 ± 0.75 mL/min (if estimated concomitantly with ultrafiltration effectiveness). These fluid transport parameters were independent of small-solute transport characteristics, but proportional to total body water estimated by bioimpedance. CONCLUSIONS: By varying the glucose concentration in 1 of 4 daily exchanges, osmotic conductance, ultrafiltration efficiency, and peritoneal fluid absorption could be estimated in CAPD patients, yielding transport parameter values that were similar to those obtained by other, more sophisticated, methods.

Ultrafiltration and dialysis adequacy with various daily schedules of dialysis fluids.

Dialysis regimens for continuous ambulatory peritoneal dialysis (CAPD) patients vary with the need for fluid removal, but also because of concerns about the local and systemic consequences of high glucose exposure. The implications of various regimens for dialysis adequacy--that is, fluid and small-solute removal--are not always clear. We therefore analyzed ultrafiltration (UF) and adequacy indices for 4 different combinations of dialysis fluid. Collections of 24-hour dialysate and urine were carried out in 99 patients on CAPD. On 4 separate occasions, each patient performed 4 exchanges in 24 hours, including 3 daily exchanges with 1.36% glucose and 1 night exchange with either 1.36% glucose (G1 schedule), 2.27% glucose (G2 schedule), 3.86% glucose (G3 schedule), or icodextrin (Ico schedule). Weekly, total, and dialysis Kt/V and KT were calculated for both urea and creatinine. The mean values of urea Kt/V and KT were significantly lower for the G1 schedule than for the G3 and Ico schedules. The adequacy indices for overnight application of 3.86% glucose and icodextrin were similar. Using dialysis fluids with 1.36% and 2.27% glucose overnight reduces glucose exposure, but those schedules may provide inadequate UF and small-solute removal in some patients (UF < 1 L daily, Kt/V < 1.7).