Mineral metabolism and mortality in dialysis patients: a reassessment of the K/DOQI guideline.

BACKGROUND: Several studies found associations between higher plasma calcium and phosphorus and mortality in dialysis patients. However, different predefined categories and reference values were applied and the precise shape of these relationships remains unclear. METHODS: We evaluated 1,621 patients from NECOSAD, a prospective multicenter cohort study of incident dialysis patients (60 +/- 15 years, 61% male, 64% hemodialysis). We used multivariate Cox regression and restricted cubic spline regression to study the effects of time-updated plasma concentrations on mortality in a flexible manner. RESULTS: 486 patients (30%) died during follow-up. Elevated phosphorus concentration was associated with higher mortality (p = 0.0009). The association of high calcium with mortality was borderline significant (p = 0.07). Within the studied ranges, we could not identify a threshold where an appreciable change in mortality risk occurred. CONCLUSIONS: Mortality risk started to increase at a relatively low phosphorus concentration (4.5 mg/dl). Low-normal calcium combined with low-normal phosphorus concentration was associated with the lowest mortality.

Cancer-associated hypercalcemia: morbidity and mortality. Clinical experience in 126 treated patients.

STUDY OBJECTIVE: To review the effects of antihypercalcemic treatment on morbidity and mortality in cancer-associated hypercalcemia. DESIGN: Retrospective study of 126 consecutive patients with cancer-associated hypercalcemia. SETTING: Inpatient referrals from a teaching hospital in the United Kingdom. INTERVENTION: Medical antihypercalcemic therapy supplemented by specific anticancer therapy where possible. MEASUREMENTS AND MAIN RESULTS: Median survival was 30 days. Survival did not differ in patients treated with different antihypercalcemic regimens but was longer (median, 135 days; P less than 0.001) in a subgroup of 26 patients for whom specific anticancer therapy was available. Polyuria and polydipsia improved after therapy in 83% of cases, central nervous system symptoms in 71%, constipation in 70%, nausea and vomiting in 56%, anorexia in 50%, and malaise and fatigue in 47% (all significant, P less than 0.001, pre-treatment compared with post-treatment). Pain control improved in only 23% of cases (not significant). Only 7% of patients with post-treatment serum calcium values above 3.50 mmol/L improved clinically compared with 80% whose calcium values fell below 2.80 mmol/L (P less than 0.001). Corresponding figures for the proportion of patients discharged from the hospital were 0% and 68% (P less than 0.001). CONCLUSIONS: Life expectancy is poor in cancer-associated hypercalcemia even in patients who are actively treated. Antihypercalcemic therapy has an important palliative role, however, because symptoms are usually improved and, in many cases, patients may be made well enough to be discharged from the hospital during the terminal stages of their illness.