Disorders in bone-mineral parameters and the risk of death in persons with chronic kidney disease stages 4 and 5: the PECERA study.

BACKGROUND: Abnormalities of bone mineral parameters are associated with increased mortality in patients on dialysis, but their effects and the optimal range of these biomarkers are less well characterized in non-dialysis chronic kidney disease (CKD). METHODS: PECERA (Collaborative Study Project in Patients with Advanced CKD) is a 3-year, prospective multicenter, open-cohort study of 966 adult patients with non-dialyzed CKD stages 4-5 enrolled from 12 centers in Spain. Associations between levels of serum calcium (Ca) (corrected for albumin), phosphate (P), and intact parathyroid hormone (iPTH) with all-cause mortality (primary outcome) and cardiovascular mortality (secondary outcome) were examined using time-dependent Cox proportional hazards models and penalized splines analysis adjusted by demographics and comorbidities, treatments and biochemical values collected every 6 months for 3 years. RESULTS: After a median follow-up of 29 months (IQR: 13-36 months) there were 181 deaths (19%). The association of calcium with all-cause mortality was J-shaped, with an increased risk for all-cause mortality at levels > 10.5 mg/dL. For phosphate and iPTH levels, the association was U-shaped. The serum values associated with the minimum risk of mortality were 3.8 mg/dL for phosphate and 70 pg/mL for iPTH, being the lowest risk ranges between 2.8 and 5.0 mg/dL, and between 38 and 112 pg/mL for phosphate and iPTH, respectively. CONCLUSIONS: Our study provides evidence on the non-linear association of serum calcium, phosphate and iPTH levels with mortality in stage 4 and 5 CKD patients, and suggests potential survival benefits for controlling bone mineral parameters in this population, as previously reported for dialysis patients.

Cohort study with patients older than 80 years with stage 5 chronic kidney failure on hemodialysis vs conservative treatment: Survival outcomes and use of healthcare resources.

Renal replacement treatment has not been generalized to the elderly for different reasons. The main objective of the present cohort study is to compare survival in patients older than 80 years with chronic kidney disease stage 5 on renal replacement treatment with those on conservative treatment. The use of healthcare resources is compared too. A Cox proportional hazards regression analysis was run with the outcome variable death during the follow-up period. The independent variables were treatment type, age, gender, smoking habit, serum albumin, hemoglobin, Charlson Index, diabetes mellitus, arterial hypertension, ischemic cardiopathy, and neoplasm. For outcome variable "death," renal replacement treatment obtained a hazard ratio of 0.273 (P .006, CI95% 0.108-0.686) vs conservative treatment. In conclusion, patients older than 80 years with chronic kidney disease stage 5 on renal replacement treatment presented a lower mortality risk than those receiving conservative treatment. Comorbidity and age are both associated with mortality, but do not cancel out the survival advantage. In healthcare resources, the renal replacement treatment group made greater use of tests, medical visits and consumption of hospital dispensing drugs, but there were no differences with respect to the days of hospital admission or assistance in home hospitalization.