Endogenous ouabain and cardiomyopathy in dialysis patients.
METHODS
Endogenous ouabain (EO) is markedly raised in patients with chronic renal failure. As high EO induces myocardial cell hypertrophy in vitro and it is associated with left ventricular hypertrophy (LVH) in essential hypertensives and in patients with heart failure we investigated the relationship between plasma EO and LV mass and geometry in 156 end-stage renal disease (ESRD) patients. EO was measured by a specific radioimmunoassay and by mass spectrometry.


RESULTS
On univariate analysis, plasma EO was directly related to LV mass (r = 0.26, P = 0.001) and LV end diastolic volume (r = 0.25, P = 0.002) and these relationships held true in multiple linear regression models including a series of potential confounders. Patients with eccentric LVH (n = 41, i.e. 26%) had the highest plasma levels of EO when compared to patients with other patterns of LV geometry (P = 0.001). Furthermore, plasma EO had diagnostic value for eccentric LVH because the area under the corresponding ROC curve (68%) was significantly greater (P = 0.002) than the threshold of diagnostic indifference. In this analysis, the sensitivity was 91% and the specificity was 36%. The positive predictive value was 33% but EO had a remarkably high negative predictive value (92%) for the exclusion of eccentric hypertrophy.


CONCLUSIONS
In ESRD patients, plasma EO is independently associated with LV mass, LV volume and eccentric LVH. The results of this study are compatible with the hypothesis that EO is involved in alterations of LV mass in ESRD.
Stella
P
P
Division of Nephrology, Dialysis, and Hypertension, University 'Vita e Salute', San Raffaele Hospital, Milan, Italy.
Manunta
P
P
Mallamaci
F
F
Melandri
M
M
Spotti
D
D
Tripepi
G
G
Hamlyn
J M
JM
Malatino
L S
LS
Bianchi
G
G
Zoccali
C
C
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood* / Q000000981:diagnostic imaging* / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010042:Ouabain / Q000097:blood*; D011237:Predictive Value of Tests; D006435:Renal Dialysis; D014463:Ultrasonography; D020257:Ventricular Remodeling / Q000502:physiology
D015415:Biomarkers; D010042:Ouabain