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Background Cardiovascular disease is the main cause of death in patients on peritoneal dialysis (PD). The standard dialysate calcium content -d[Ca]- of 1.75mmol/L affects calcium balance, promoting calcium overload and impairing ventricular relaxation. Intracellular calcium handling might cause diastolic dysfunction (DD). We tested the hypothesis that reducing d[Ca] in patients on PD would improve DD. Methods d[Ca] was reduced from 1.75 mmol/L to 1.25 mmol/L. Two-dimensional speckle-tracking echocardiography was performed by a well-trained cardiologist at baseline and after 3 months. DD was determined according to the peak E-wave and peak A-wave velocities, wave deceleration time, and the duration of wave A. Diastolic function was normal, DD-1 (impaired ventricular relaxation), and DD-2 (restrictive pattern). Demographic, clinical, and biochemical parameters were evaluated. Results We included 19 patients (age 55 ± 17 years, 57.9% women, 21.1% diabetic, 84.2% on automatic PD). From baseline to 3 months, there was no change in any biochemical parameter. Left ventricular ejection fraction remained stable (from 58.4 ± 7.7 to 56.5 ± 8.1, p=0.192). Diastolic function classified at baseline as normal, DD-1 and DD-2 changed from 21.1%, 52.6% and 26.3–31.6%, 47.4% and 21.1% after 3 months, respectively, p=0.001). Increased filling pressure changed from 21.1–5.3% of patients (p=0.051). Conclusions Low d[Ca] could improve DD in patients on PD. This result might be related to a new set point of calcium myocardium homeostasis in these patients. Whether low d[Ca] may detain the development of heart failure and reduce cardiovascular in this population deserves further investigation.

Peritoneal equilibration test (PET) is the gold standard for evaluating peritoneal transport, and measurement of the drain volume after 4‐h dwell time with glucose 4.25% is a simple means of evaluating failure of ultrafiltration. The study objective was to verify if the measurement of the volume drained after 4 h dwell of icodextrin at 7.5% (ICO), has a better correlation with the parameters of PET. Patients in a peritoneal dialysis program (N = 35) underwent three procedures: PET; determination of the drain volume after a 4‐h dwell with glucose 4.25%; and determination of the drain volume after a 4‐h dwell with ICO. Among patients who were classified as high transporters, the ultrafiltration volume was greater after ICO use. The ICO ultrafiltration volume correlated negatively with the ratio between the 4‐ and 0‐h dialysate glucose concentrations (D4/D0 ratio, r = −0.579; P = 0.002), correlating positively with the dialysate‐to‐plasma ratio for creatinine (D/PCr ratio, r = 0.474; P = 0.002). For ICO, the area under the receiver operating characteristic curve was 0.867 and 0.792 for the D/PCr and D4/D0 ratios (P < 0.0001 and P = 0.004, respectively), compared with 0.738 and 0.710 for glucose 4.25% (P = 0.020 and P = 0.041, respectively). A cut‐off volume of 141 mL discriminated high/high‐average transporters from low/low‐average transporters. Volume drained after ICO use better predicts peritoneal transport patterns than does that drained after the use of glucose 4.25%.

Introduction: Patients on peritoneal dialysis (PD) are usually exposed to a high dialysate calcium concentration (D[Ca]), which is associated with undesirable effects. Low D[Ca] might overstimulate parathyroid hormone (PTH), as shown by previous studies carried out before the incorporation of calcimimetics in clinical practice. We hypothesized that a reduction in D[Ca] is safe and without risk for a rise in serum PTH. Methods in this prospective study, the D[Ca] was reduced from 1.75 mmol/L to 1.25 mmol/L for one year in prevalent patients on PD. Demographic, clinical, and biochemical parameters were evaluated at baseline, 3, 6, and 12 months of follow-up. Results Patients (N = 20) aged 56 ± 16 years, 50% male, 25% diabetic. There was no significant change in calcium, phosphate, alkaline phosphatase, 25(OH)-vitamin D or PTH over time. Medication adjustments included an increase in calcitriol and sevelamer. After 1 year, absolute and percentual change in PTH levels were 36 (-58, 139) pg/ml, and 20% (-28, 45) respectively. The proportion of patients with PTH > 300 pg/ml did not change during the follow-up (p = 0.173). Conclusion Low D[Ca] concentration should be considered to patients on PD as a valuable and safe option. Medication adjustments to detain PTH rising, however, are advised.