Effect of an L-carnitine-containing peritoneal dialysate on insulin sensitivity in patients treated with CAPD: a 4-month, prospective, multicenter randomized trial.

BACKGROUND: In peritoneal dialysis, the high glucose load absorbed from dialysis fluid contributes to several metabolic abnormalities, including insulin resistance. We evaluate the efficacy of a peritoneal dialysis solution containing l-carnitine as an additive to improve insulin sensitivity. STUDY DESIGN: Multicenter parallel randomized controlled trial. SETTING & PARTICIPANTS: Nondiabetic uremic patients on continuous ambulatory peritoneal dialysis enrolled in 8 peritoneal dialysis centers. INTERVENTION: Patients were randomly assigned to receive peritoneal dialysis diurnal exchanges with either a standard glucose-based solution (1.5% or 2.5% according to the patient's need) or a glucose-based solution (identical glucose amount) enriched with l-carnitine (0.1%, weight/volume; 2 g/bag) for 4 months, the nocturnal exchange with icodextrin being unmodified. OUTCOMES & MEASUREMENTS: The primary outcome was insulin sensitivity, measured by the magnitude of change from baseline in glucose infusion rate (in milligrams per kilogram of body weight per minute) during a euglycemic hyperinsulinemic clamp. Secondary outcomes were safety and tolerability, body fluid management, peritoneal dialysis efficiency parameters, and biochemistry tests. RESULTS: 35 patients were randomly assigned, whereas 27 patients (standard solution, n=12; experimental solution, n = 15) were analyzed. Adverse events were not attributable to treatment. Glucose infusion rates in the l-carnitine-treated group increased from 3.8 ± 2.0 (SD) mg/kg/min at baseline to 5.0 ± 2.2 mg/kg/min at day 120 (P = 0.03) compared with 4.8 ± 2.4 mg/kg/min at baseline and 4.7 ± 2.4 mg/kg/min at day 120 observed in the control group (P = 0.8). The difference in glucose infusion rates between groups was 1.3 (95% CI, 0.0-2.6) mg/kg/min. In patients treated with l-carnitine-containing solution, urine volume did not change significantly (P = 0.1) compared to a significant diuresis reduction found in the other group (P = 0.02). For peritoneal function, no differences were observed during the observation period. LIMITATIONS: Small sample size. CONCLUSIONS: The use of l-carnitine in dialysis solutions may represent a new approach to improving insulin sensitivity in nondiabetic peritoneal dialysis patients.

Prevalence and progression of cardiovascular calcifications in peritoneal dialysis patients: A prospective study.

BACKGROUND: Patients on dialysis may have abnormal serum levels of Ca, P and parathyroid hormone, with related bone diseases. This population has an increased risk of death, with cardiovascular calcification (CC) a contributing factor. Patients on peritoneal dialysis appear to be at increased risk of hyperlipidemia, a contributing factor to atherosclerotic plaque formation. Although several studies have described the presence and progression of CC in hemodialysis populations, there are fewer data in patients on peritoneal dialysis. STUDY DESIGN: The Renal Osteodystrophy and Calcifications: Key factors in Peritoneal Dialysis (ROCK-PD) study was a 36-month, prospective observational study conducted in Italy. The study examined the presence and progression of CC in two cardiac valves and five arterial sites. The potential associations of serum Ca and P with mortality and cardiovascular morbidity, demographic, clinical and blood chemistry variables was investigated. RESULTS: CC was present in 77% of patients at baseline (N=369) and in 90% of patients by study end (N=145), progressing in 73% of patients. There were 42 deaths (11%). Analyses showed a marked correlation between baseline P levels and the presence of left ventricular hypertrophy. However, there were no consistent correlations between serum Ca or P with mortality or morbidity. CONCLUSIONS: CC was common in peritoneal dialysis patients and progressed in a majority of patients.

In vitro microbiology studies on a new peritoneal dialysis connector.

OBJECTIVE: We evaluated the ability of a recently developed peritoneal dialysis (PD) connector to prevent the risk of bacterial transfer to the fluid path after simulated touch and airborne contamination. METHODS: Staphylococcus epidermidis ATCC1228 and Pseudomonas aeruginosa ATCC27853 strains were used. For touch contamination, 2 µL of a standardized inoculum [1×10(8) colony-forming units (CFU) per milliliter] were deposited on top of the pin closing the fluid path of the patient connector. For airborne contamination, the patient connector was exposed for 15 seconds to a nebulized standardized inoculum. To simulate the patient peritoneum and effluent, the patient connector was pre-attached to a 2-L bag of sterile PD solution. After contamination, the patient connector was attached to the transfer set, the pin was captured, flow control was turned to simulate "patient drain" into the empty bag, and then "patient fill" using the bag pre-attached to the connector. Finally, a new pin was recaptured. The PD solution collected in the bag pre-attached to the connector was run through a 0.20-µm filter for colony counts. RESULTS: No infected connector transferred bacteria to the fluid path, regardless of the challenge procedure or the strain used. CONCLUSIONS: Our results show that the new PD connector may fully obviate the risk of bacterial infection, even in the presence of heavy contamination. Further studies are in progress to test our PD connector in a clinical setting.