Prevalence and cardiovascular risk profile of chronic kidney disease in Italy: results of the 2008-12 National Health Examination Survey

Background: National surveys in countries outside Europe have reported a high prevalence (11-13%) of chronic kidney disease (CKD). Studies in Europe have provided a variable prevalence likely due to differences in study design, including age and extent of geographic areas, equation used to evaluate estimated glomerular filtration rate (eGFR) and CKD stages examined.

Methods: The 2008-12 National Health Examination Survey in Italy randomly extracted samples from the general population aged 35-79 years, stratified by age and gender, from the resident list of each Italian region (440 persons/1.5 million of residents). We estimated the prevalence of CKD by means of urinary albumin : creatinine ratio and eGFR (CKD-EPI equation-enzymatic assay of serum creatinine). Cardiovascular (CV) risk profile was also evaluated.

Results: Three thousand eight hundred and forty-eight men and 3704 women were examined. In the whole population, mean age was 57 ± 12 and 56 ± 12 years in men and women, respectively; hypertension was prevalent in men and women, respectively (56 and 43%) and the same held true for overweight (48 and 33%), obesity (26 and 27%), diabetes (14 and 9%) and smoking (21 and 18%), whereas CV disease was less frequent (9 and 6%). Overall, the prevalence of CKD (95% confidence interval) was 7.05% (6.48-7.65). Early stages constituted 59% of the CKD population [Stage G1-2 A2-3: 4.16% (3.71-4.61) and Stage G3-5: 2.89% (2.51-3.26)]. At multivariate regression analysis, age, obesity, hypertension, diabetes, CV disease and smoking were all independent correlates of CKD.

Conclusions: CKD has a relatively lower prevalence in Italy, in particular for advanced stages, when compared with similar national surveys outside Europe. This occurs despite older age and unfavourable CV risk profile of the whole population.