Urinary prostaglandins (PGE2 and PGI2) in hyporeninaemic hypoaldosteronism in diabetic patients with chronic renal failure

The present work studies the urinary excretion of PGE₂ and PGI₂(6-keto PGF 1) in 11 insulin-dependent diabetic patients withchronic renal failure with a glomerular filtration rate of 33.9±9.03 ml/min who had hyporeninaemic hypoaldosteronismto evaluate the influence of these prostaglandins on the appearanceof this latter process. The results obtained in this group ofpatients were compared with those of a control group of healthyindividuals, another group of nine non-diabetic patients withCRF, and a last group of eight insulin-dependent diabetic patientswith normal renal functión to evaluate to what extentthe possible variations in prostaglandin excretion could berelated to the diabetes, CRF, or a conjunction of both processes. The results of the groups of diabetic patients with CRF wereC_cr 33.9 ±9.03 ml/min, decreased (P< 0.0001) withrespect to the control group and with no difference with theCRF group without diabetes; plasma potassium (4.7 ±0.4mEq/l), increased P<0.005) with respect to the values foundin the control group; plasma bicarbonate (17.8 ± 1.8mEq/l), decreased (P< 0.005) with respect to the controlgroup and also, though not significantly, with respect to thegroup of non-diabetic patients with CRF. Plasma aldosterone(pg/ml): resting 44.3±14.9; standing 65.7 ±63.5and post-frusemide 65.5 ±58.6, decreased (P<0.01)with respect to the other three groups. Plasma renin activity(PRA) (ng/ml/h): resting 0.34±0.3; standing 0.6 ±0.4, post-fmsemide 0.9 ±0.5, decreased significantlywith respect to the other three groups. PGE₂ (pg/mg Cr): basal1720±397; post-frusemide 2636±462, increased (P<0.05)with respect to the control group and that of the diabetic patientswithout CRF, but with no differences compared with the non-diabeticpatients with CRF. PGI₂ (pg/mg cr): basal 369 ±45 andpost-frusemide 699 ± 103, increased (P<0.01) withrespect to the controls and diabetic patients with normal renalfunction and with no differences compared with the non-diabeticpatients with CRF. Our findings indicate that patients with diabetes mellitus andCRF showing hyporeninaemic hypoaldosteronism have high urinaryexcretion of PGE₂ and PGI₂. The increase in the urinary prostaglandinsis related to CRF. The data rule out the hypothesis that thehyporeninaemic hypoaldosteronism of these patients is due toa deficit of prostaglandins.     

Erythropoietin requirements: a comparative multicenter study between peritoneal dialysis and hemodialysis

BACKGROUND: The management of anemia with erythropoietin (EPO) is important in the global treatment of dialysis patients. There is a general impression that anemia control with EPO is obtained more easily in peritoneal dialysis (PD) patients than in hemodialysis (HD) patients. The EPO administration route has to be the same to compare the two techniques adequately. METHODS: To compare EPO action by subcutaneous (SC) route in HD and PD, 132 stable patients were recruited (HD: 69, PD: 63) from six centers, with adequate dialysis criteria (Kt/V in HD >1.3; weekly Kt/V in PD >1.8). In a cross-sectional study, the EPO dose/week, the number of EPO doses/week, hemoglobin (Hb), ferritin, transferrin saturation index (TS), albumin and intact parathyroid hormone (iPTH) were analyzed. Iron treatment, comorbidity and ACE inhibitors (ACEI) and angiotensin II antagonist (AIIA) treatment were recorded. A multivariate regression model was used in the statistical analysis. RESULTS: The mean Hb level was the same in both groups, HD 11.6 (1.3) g/dL, PD 11.4 (1.4) g/dL, p=0.3. The SC, EPO doses required to obtain the Hb levels were higher in HD than in PD patients, with a difference of 64.3 u/Kg/week, statistically significant in the multivariate regression model (p=0.001, 95% CI 42.6-86.0). The number of EPO doses/week was also higher in HD patients (65% of HD patients with > or = 3 doses, 19% of PD patients with three or more doses, p<0.001). TS was similar in both groups, while ferritin was higher in HD patients, with a higher percentage of HD patients using intravenous (i.v.) iron (HD 77% vs. PD 49%, p=0.001). Serum albumin and iPTH were lower in PD patients (p<0.001 and p=0.04, respectively), but the percentage of patients with intact parathyroid hormone (iPTH) >500 pg/mL was similar in both groups (HD 17%, PD 14%). CONCLUSIONS: With the same administration route, PD patients showed a reduced EPO requirement, and less frequent EPO administration than HD patients, to obtain the same Hb level. No other factors, except those involved in better depuration of erythropoiesis inhibitors in PD, seemed responsible for the different EPO requirements.