Prevalence of chronic kidney disease and associated factors in the Spanish population attended in primary care: Results of the IBERICAN study

Objectives: To determine the prevalence of chronic kidney disease (CKD) and the factors associated with impaired renal function in the population attended in primary care (PC). Patients and method: Cross-sectional and multicentre study carried out in the baseline patients of the IBERICAN study (Identificación de la poBlación Española de RIesgo CArdiovascular y reNal). CKD was considered with an estimated glomerular filtration (eGF) < 60 ml/min/1.73 m² or elevated albuminuria (≥ 30 mg/g). According to the eGF, the CKD was classified in six stages (1, 2, 3a, 3b, 4 and 5) and according to albuminuria in three stages (A1 or normal / slightly increased, A2 or moderately increased and A3 or severely increased). The clinical characteristics and the relationship of CKD with the main cardiovascular risk factors (CVRF) and other variables of interest were analysed using unconditional logistic regression. Results: 7,895 patients were included (mean age 57.9 ± 14.8 years; 54.5% women). 14.4% (95% CI: 13.6-15.1) had CKD; 16.1% (95% CI: 14.9-17.3) in men and 12.9% (95% CI: 11.9-14.0) in women. A continuous increase of the prevalence was observed with age (24.8% in ≥ 65 years) and with CVFR aggregation. The variables that were most associated with the probability of suffering CKD were left ventricular hypertrophy (OR: 1.95; p < .001), diabetes (OR: 1.58; P < .001) and hypertension (OR: 1.56; P < .001). Conclusions: Fourteen out of every 100 patients included in the IBERICAN study have CKD. The prevalence of CKD affects a quarter of patients ≥ 65 years and increases exponentially with the aggregation of FRCV.