Baseline characteristics of patients with chronic kidney disease stage 3 and stage 4 in Spain: the MERENA observational cohort study

• Published in: BMC nephrology Vol. 12; no. 1; p. 53
• Main Authors: Martínez-Castelao, Alberto, Górriz, José L, Portolés, José M, De Alvaro, Fernando, Cases, Aleix, Luño, José, Navarro-González, Juan F, Montes, Rafael, De la Cruz-Troca, Juan J, Natarajan, Aparna, Batlle, Daniel
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 05.10.2011; BioMed Central; BMC
• Subjects: Adult; Aged; Aged, 80 and over; Analysis; Anemia; Anemia - epidemiology; Anemia - metabolism; Antihypertensive Agents - therapeutic use; Calcium - blood; Cardiovascular disease; Care and treatment; Case formulation; Chronic diseases; Chronic kidney failure; Clinics; Cohort Studies; Development and progression; Diabetes Mellitus, Type 1 - epidemiology; Diabetes Mellitus, Type 2 - epidemiology; Diagnosis; Espanya; Female; Follow-Up Studies; Formulació clínica; Heart attacks; Humans; Hypertension, Renal - drug therapy; Hypertension, Renal - epidemiology; Iron - metabolism; Kidney diseases; Malalties cròniques; Malalties del ronyó; Male; Middle Aged; Minerals - metabolism; Morbidity; Mortality; Nefrologia; Nephrology; Phosphorus - blood; Physiological aspects; Proteinuria - blood; Proteinuria - epidemiology; Proteinuria - physiopathology; Renal Insufficiency, Chronic - blood; Renal Insufficiency, Chronic - epidemiology; Renal Insufficiency, Chronic - physiopathology; Risk factors; Severity of Illness Index; Spain; Spain - epidemiology; Studies; Young Adult; Spain
• ISSN: 1471-2369; 1471-2369
• DOI: 10.1186/1471-2369-12-53

To obtain information on cardiovascular morbidity, hypertension control, anemia and mineral metabolism based on the analysis of the baseline characteristics of a large cohort of Spanish patients enrolled in an ongoing prospective, observational, multicenter study of patients with stages 3 and 4 chronic kidney diseases (CKD). Multicenter study from Spanish government hospital-based Nephrology outpatient clinics involving 1129 patients with CKD stages 3 (n = 434) and 4 (n = 695) defined by GFR calculated by the MDRD formula. Additional analysis was performed with GFR calculated using the CKD-EPI and Cockcroft-Gault formula. In the cohort as a whole, median age 70.9 years, morbidity from all cardiovascular disease (CVD) was very high (39.1%). In CKD stage 4, CVD prevalence was higher than in stage 3 (42.2 vs 35.6% p < 0.024). Subdividing stage 3 in 3a and 3b and after adjusting for age, CVD increased with declining GFR with the hierarchy (stage 3a < stage 3b < stage 4) when calculated by CKD-EPI (31.8, 35.4, 42.1%, p 0.039) and Cockcroft-Gault formula (30.9, 35.6, 43.4%, p 0.010) and MDRD formula (32.5, 36.2, 42.2%,) but with the latter, it did not reach statistical significance (p 0.882). Hypertension was almost universal among those with stages 3 and 4 CKD (91.2% and 94.1%, respectively) despite the use of more than 3 anti-hypertensive agents including widespread use of RAS blockers. Proteinuria (> 300 mg/day) was present in more than 60% of patients and there was no significant differences between stages 3 and 4 CKD (1.2 ± 1.8 and 1.3 ± 1.8 g/day, respectively). A majority of the patients had hemoglobin levels greater than 11 g/dL (91.1 and 85.5% in stages 3 and 4 CKD respectively p < 0.001) while the use of erythropoiesis-stimulating agents (ESA) was limited to 16 and 34.1% in stages 3 and 4 CKD respectively. Intact parathyroid hormone (i-PTH) was elevated in stage 3 and stage 4 CKD patients (121 ± 99 and 166 ± 125 pg/mL p 0.001) despite good control of calcium-phosphorus levels. This study provides an overview of key clinical parameters in patients with CKD Stages 3 and 4 where delivery or care was largely by nephrologists working in a network of hospital-based clinics of the Spanish National Healthcare System.