Association between proteinuria and left ventricular mass index: a cardiac MRI study in patients with chronic kidney disease.
BACKGROUND
Chronic kidney disease (CKD) is associated with increased cardiovascular morbidity and mortality. We hypothesized that the level of proteinuria would correlate with left ventricular mass, providing a potential link between elevated protein excretion, left ventricular hypertrophy (LVH) and the increased mortality seen in patients with CKD. In order to do this, we assessed the determinants of left ventricular mass, measured using cardiac magnetic resonance (CMR) imaging, in patients with CKD.


METHODS
Patients attending the renal clinic with CKD stages 2-4 and diabetic nephropathy (n = 26) and IgA nephropathy (n = 23) were recruited. They underwent detailed demographic, biochemical and vascular phenotyping and CMR imaging. Proteinuria was measured using spot protein:creatinine ratio (PCR). Left ventricular mass index (LVMI) was calculated from short-axis cine imaging using Argus software and adjusted for body surface area.


RESULTS
Log-PCR correlated significantly with LVMI, as did waist circumference, pulse pressure and systolic blood pressure. LVMI was higher in men. When these variables were entered into a linear regression model, log-PCR (P = 0.006) and systolic blood pressure (P < 0.001) independently predicted LVMI. Renal function was not associated with LVMI.


CONCLUSIONS
Using volume-independent CMR imaging, we have demonstrated that the level of urinary protein excretion is independently and significantly associated with left ventricular mass in patients with CKD. This relationship was independent of blood pressure. This finding provides a novel link between CKD and increased cardiovascular risk.
McQuarrie
Emily P
EP
Renal Diseases and Hypertension, University of Colorado Denver Health Sciences Center, Aurora, CO, USA. emilypf@hotmail.com
Patel
Rajan K
RK
Mark
Patrick B
PB
Delles
Christian
C
Connell
John
J
Dargie
Henry J
HJ
Steedman
Tracey
T
Jardine
Alan G
AG
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D003928:Diabetic Nephropathies / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis* / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000601:surgery*; D007677:Kidney Function Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000175:diagnosis* / Q000209:etiology; D012307:Risk Factors
D003404:Creatinine