Background: Chronic renal insufficiency (CRI) is a strong predictor of increased mortality in the presence of heart failure (HF) and its prevalence has been increasing in the US. In addition, CRI is a major contributing factor to the progression of HF as it is associated with chronic volume overload, accelerated atherosclerosis and hypertension (HTN). The first aim of the current study was to evaluate the prevalence of CRI in an adult general population. The second aim was to address whether calculated glomerular filtration rate (cGFR) adds value to the cardiac biomarkers BNP and NT-proBNP in detecting early cardiac structural and functional impairments in the general population.
Methods: From 1997 to 1999 medical history, physical examination, echocardiography, BNP (Biosite) and NT-proBNP (Roche) and serum creatinine (SCr) were obtained in 1,982 randomly selected residents of Olmsted County, MN >= 45 years (range 45 – 96 years). GFR was calculated using the Cockroft Gault equation. CRI was defined as a GFR < 60 ml/min. Cardiac structure and function were evaluated by in-depth echocardiographic examination.
Results: The prevalence of cardiovascular co-morbidities was coronary atherosclerosis 12%, HTN 29.5% and diabetes mellitus 7.5%. The prevalence of CRI was 22.8% when cGFR was used for its detection. Importantly, by Chi-Square model, cGFR significantly increased the ability of BNP in detecting left ventricular hypertrophy (LVH) (p=0.004), increased relative wall thickness (p=0.0036), diastolic dysfunction (DDF) (p=0.0001) and HTN (p=0.0002). Similarly, when combined with NT-proBNP, cGFR increased the predictive power of detecting DDF (p=0.0001) and HTN (p=0.0366).
Conclusion: This study reports a higher than predicted prevalence of CRI in this general US population equal to 23% and closely associated with the prevalence of HTN (29.5%). Importantly, this study also demonstrates that cGFR has additive predictive power when used in combination with two cardiac biomarkers of cardiac dysfunction and remodeling, BNP and NT-proBNP. These studies underscore the increasing burden of CRI in the general population and the utility of assessing cardiorenal function by combining renal and cardiac biomarkers in assessment of cardiac structure and function.
Cardiac Structure and Function and Renal Insufficiency in the Oldest Old
