Background: Chronic kidney disease (CKD) is a major worldwide problem. A lack of CKD awareness and knowledge of associated risk factors may delay diagnosis and treatment. The purpose of this epidemiological study was to assess the presence and awareness of CKD, in addition to evaluating associated clinical characteristics.
Methods: This cross-sectional observational study included 573 healthy volunteers (aged 21-62 years) based in central Italy. All participants underwent a nephrological visit, providing data on medical history, anamnesis and CKD awareness. Blood and urine samples were also collected.
Results: Estimated glomerular filtration rate (eGFR) calculated by the abbreviated Modification of Diet in Renal Disease (MDRD) study formula revealed that 55% of participants had an eGFR of <90 ml/min per 1.73 m2 compared with 24.6% by the Cockcroft-Gault formula (C-G; p<0.0001). Approximately 45% of participants showed an awareness of CKD, these subjects also having a significantly lower Framingham score (p<0.046). Approximately half of participants (51%) had insufficient levels (<30 ng/mL) of serum 25-hydroxyvitamin D (25(OH)D), with a higher proportion observed in female (58.3%) than male participants (45.6%, p=0.0016). Levels of 25(OH)D were negatively correlated with eGFR, measured by either MDRD or C-G (r=-0.12, p=0.0039 and r=-0.09, p=0.029 respectively). Logistic regression analysis revealed that male sex and increased serum creatinine levels were predictors associated with study outcomes (clinical risk factors).
Conclusions: This study suggests that screening for CKD in the general population by eGFR calculations (MDRD or C-G) is unreliable; therefore, the monitoring of serum creatinine and other risk factors may be more appropriate. The presence of vitamin D insufficiency in apparently healthy individuals warrants further investigation.