Prevalence of chronic kidney disease in a representative sample of the Polish population: results of the NATPOL 2011 survey.
BACKGROUND
Chronic kidney disease (CKD) has been proven to be a major risk factor of cardiovascular disease (CVD). Until now, data on the prevalence of CKD among adults in Poland were limited. The NATPOL 2011 survey is a cross-sectional observational study designed to assess the prevalence and control of CVD risk factors in Poland, and the first study capable of evaluating CKD prevalence in adult Polish citizens.


METHODS
Serum creatinine concentration and the urine albumin-to-creatinine ratio (ACR) were measured in 2413 randomly selected participants (ages 18-79 years) from a national survey study. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) was <60 mL/min/1.73 m(2) or ≥60 mL/min/1.73 m(2) with coexisting albuminuria (ACR ≥ 30 mg/g). Additionally, comorbidities and anthropometric and social factors related to the prevalence of CKD were analysed.


RESULTS
The prevalence of CKD was estimated at 5.8% [95% confidence interval (95% CI) 4.6-7.2] using Chronic Kidney Disease Epidemiology Collaboration formula. The general prevalence was higher when the MDRD was applied [6.2% (95% CI 4.0-7.6)]. An eGFR <60 mL/min/1.73 m(2) was found in 1.9% (95% CI 1.5-2.5) of the studied population. This was accompanied by low awareness of this condition (14.9%). The frequency of albuminuria was estimated at 4.5% (95% CI 3.4-5.9). Diabetes mellitus (DM) and arterial hypertension (AH) were more frequent among respondents with diagnosed CKD compared with those without CKD [18.5 versus 4.5% (P < 0.001) and 67.8 versus 29.0% (P < 0.001) respectively]. DM and AH were, apart from increasing age, the two greatest risk factors of CKD.


CONCLUSION
The estimated prevalence of CKD among adults in Poland is 5.8% (∼1 724 960 patients). Its prevalence was lower than expected. CKD is more frequent in older subjects, smokers and people with comorbidities such as AH and DM.