Abstract and Introduction
Abstract
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.
Introduction
Chronic kidney disease (CKD) is a prevalent condition and public health priority worldwide. Aging, nutrition status, prevalence of infectious diseases and environmental and genetic factors, as well as access to health care, can profoundly modify CKD epidemiology. Prevalence of end-stage renal disease (ESRD), in fact, differs substantially across countries. More important, mortality related to CKD has almost doubled in the past two decades worldwide, with the overall increase in years of life lost due to premature mortality being the third largest behind HIV–AIDS and diabetes mellitus. Even moderate reductions in estimated glomerular filtration rate (eGFR) and/or increases in albuminuria worldwide enhance the risk of ESRD as well as all-cause and cardiovascular (CV) death independently of age, hypertension and diabetes. Therefore, CKD is a public health priority characterized by poor prognosis worldwide and variable prevalence across countries.
Studies estimating at the national level the prevalence of CKD are urgently needed to properly inform health-care planners and to increase awareness of this problem, which remains disturbingly low in the general population and in the medical community as well. National, population-based surveys of CKD prevalence that incorporate both albuminuria and proper estimates of eGFR [i.e. based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation have been conducted in North America, China and Australia. These studies reported a high prevalence (11–13%) of CKD in the general adult population. In Europe, similar prevalence rates have been suggested; however, these studies were mostly based on the MDRD equation, were geographically circumscribed to regions or towns, or did not examine the early (albuminuric) stages.
The first survey of the Cardiovascular Epidemiology Observatory/Health Examination Survey (OEC/HES) in Italy, founded by the Italian Ministry of Health, was performed between 1998 and 2002 by the National Institute of Health (ISS) and the National Association of Hospital Cardiologists (ANMCO) to provide a complete picture of the Italian population's health and to facilitate implementation of preventive programmes. From 2008 to 2012, a second survey was conducted using the same methodologies and procedures used in the first survey. Here, we describe the results of CArdiovascular risk profile in Renal patients of the Italian Health Examination Survey (CARHES), a project embedded into the OEC/HES 2008–12. CARHES aimed at estimating the prevalence of a whole spectrum of CKDs and associated CV risk factors in a nationally representative sample from the general adult population in Italy.