Vitamin D and cinacalcet are associated with increased survival in peritoneal dialysis but not with residual renal function preservation
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BACKGROUND: Active vitamin D and cinacalcet, a treatment for secondary hyperparathyroidism and also with potential anti-inflammatory properties, have been associated with lower risk of death among dialysis patients. Vitamin D has also been described to decrease proteinuria in CKD patients. This study aims to assess the relationship of vitamin D and cinacalcet with survival and residual renal function preservation among peritoneal dialysis patients. MATERIALS AND METHODS: In a retrospective peritoneal dialysis cohort of 581 subjects, we assessed if vitamin D and cinacalcet therapy are associated with increased risk of death and residual renal function loss using Kaplan-Meier analysis and Cox proportional hazard analysis. RESULTS: Vitamin D treatment was associated with a 56% reduction in the risk of death (HR 0.44, 95% CI 0.28 - 0.67) and cinacalcet also with a 54% lower risk of death (HR 0.46, 95% CI 0.31 - 0.69) in multivariate models adjusting for each other. Hyperphosphatemia (> 6 mg/dL) was associated with an 85% increase in mortality (HR 1.85, 95% CI 1.30 - 2.65). Neither vitamin D (HR 1.04, 95% CI 0.45 - 2.39) nor cinacalcet (HR 0.74, 95% CI 0.45 - 1.20) were associated with a lower risk of anuria. CONCLUSION: Vitamin D and cinacalcet therapy was associated with a lower risk of death but not anuria, beyond other known risk factors among peritoneal dialysis patients.
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Rapid Change in Residual Renal Function Decline Is Associated with Lower Survival and Worse Residual Renal Function Preservation in Peritoneal Dialysis Patients.

The survival advantage observed among peritoneal dialysis patients early on after dialysis initiation has been largely attributed to residual renal function (RRF) preservation due to higher baseline residual function and fewer comorbidities. We hypothesize that a rapid decline in RRF is associated with higher risk of anuria and mortality. In a retrospective cohort study of 581 subjects on peritoneal dialysis with longitudinal prevalent data, we assessed whether RRF change over time, in addition to baseline RRF, increased risk of mortality and anuria using Kaplan-Meier analysis and Cox proportional hazard analysis to control for known risk factors. Rapid RRF decline (≥ 0.09 decline) over a 12-month period was associated with a 2.6-fold increase in the risk of death (hazard ratio [HR] 2.60, 95% confidence interval [CI] 1.66 - 4.07, compared with < 0.09 decline) and a 2-fold increase in anuria (HR 2.06, 95% CI 1.24 - 3.42). Each quartile of increasing severity of RRF decline over a 12-month period increased risk incrementally for death (2nd quartile: HR 3.04, CI 1.26 - 7.34; 3rd quartile: HR 4.01, CI 1.71 - 9.83; 4th quartile HR 5.78, CI 2.10 - 15.9) and generally for anuria (quartiles with HR 5.72 - 7.21). The escalating risk of mortality and anuria was greater for those with diabetes mellitus. In conclusion, rapid decline in RRF over a 12-month period increased the risk of mortality and likewise anuria, beyond previously established risk factors for mortality and anuria. The impact on mortality and RRF preservation was particularly severe for those with diabetes mellitus.