Is valvular calcification a part of the missing link between residual kidney function and cardiac hypertrophy in peritoneal dialysis patients?
OBJECTIVE
Residual renal function (RRF) predicts survival and shows an important inverse relation with cardiac hypertrophy in peritoneal dialysis (PD) patients. We hypothesized that valvular calcification and the calcification milieu may be part of the process linking loss of RRF and cardiac hypertrophy.


METHODS
A cross-sectional study was conducted by performing two-dimensional echocardiography on 230 PD patients to assess valvular calcification and left ventricular (LV) mass and collecting 24-h urine for estimation of RRF.


RESULTS
Patients having valvular calcification had lower RRF than those without. Patients with no RRF showed higher calcium-phosphorus product (Ca x P) and C-reactive protein (CRP). Using multiple logistic regression analysis, every 1-ml/min per 1.73 m(2) increase in residual GFR was associated with a 28% reduction in the risk for valvular calcification. The association was lost after additional adjustment for Ca x P and CRP. Using multiple linear regression analysis, loss of RRF showed significant association with increased LV mass index, but this association was lost after additional adjustment for CRP, Ca x P, and valvular calcification. Patients with all three calcification risk factors, namely inflammation, high CaxP, and no RRF, showed the highest prevalence of valvular calcification and had the most severe cardiac hypertrophy.


CONCLUSIONS
The association among loss of RRF, valvular calcification, and cardiac hypertrophy was closely linked to increased inflammation and high Ca x P in PD patients. These data suggest that valvular calcification and the calcification milieu are part of the processes linking loss of RRF and worsening cardiac hypertrophy in PD.
Wang
Angela Yee-Moon
AY
University Department of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong. aymwang@hku.hk
Lam
Christopher Wai-Kei
CW
Wang
Mei
M
Chan
Iris Hiu-Shuen
IH
Lui
Siu-Fai
SF
Sanderson
John E
JE
D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis; D002114:Calcinosis / Q000150:complications*; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D005919:Glomerular Filtration Rate; D006349:Heart Valve Diseases / Q000150:complications*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000209:etiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*
D002097:C-Reactive Protein