Metabolic syndrome and other cardiovascular risk factors associated with the progression of IgA nephropathy.
BACKGROUND
The metabolic syndrome is associated with modest but independent and additive risk of new onset chronic kidney disease (CKD) in several studies. The purpose of our study was to determine whether metabolic syndrome and other cardiovascular risk factors (hyperuricaemia and smoking) are associated with the progression of IgA nephropathy (IgAN).


METHODS
Two hundred and twenty three IgAN patients (107 with and 116 without metabolic syndrome) were examined. The primary renal end point was doubling of serum creatinine; secondary end points were reaching eGFR of ≤ 60 ml/min/1,73m(2) or eGFR of ≤30 ml/min/1.73 m(2), and end-stage renal disease, ESRD (the composite of serum creatinine ≥500 μmol/l, initiation of dialysis treatment or transplantation). The association of metabolic syndrome with renal end points was examined using the Kaplan-Meier method and Cox models.


RESULTS
Metabolic syndrome established at the diagnosis or during follow-up of IgAN patients was significantly associated with the primary renal end point (unadjusted hazard ratio of doubling of serum creatinine, 95% confidence interval: 1.96 (1.17-1.33, p = 0.011). The association remained significant after adjustment for confounders: 1.70 (1.02-3.83, p = 0.040). Results were similar for secondary end points except ESRD which was not associated with the presence of metabolic syndrome. Hyperuricaemia and smoking were independent risk factors of progression. Survival curves stratified on metabolic syndrome status showed significant differences for the end points (p = 0.017-0.001) except for ESRD.


CONCLUSIONS
Early diagnosis and treatment of metabolic syndrome, hyperuricaemia and smoking may be an additional cost-effective strategy for preventing the progression of IgAN.
Second Department of Medicine and Nephrological Center, Faculty of Medicine , University of Pécs, Pécs , Hungary.
Tibor
T
Kovács
Second Department of Medicine and Nephrological Center, Faculty of Medicine , University of Pécs, Pécs , Hungary.
Tibor
T
Vas
Health Science Center , University of Tennessee , Memphis, TN , USA.
Csaba P
CP
Kovesdy
Second Department of Medicine and Nephrological Center, Faculty of Medicine , University of Pécs, Pécs , Hungary.
István
I
Késõi
Second Department of Medicine and Nephrological Center, Faculty of Medicine , University of Pécs, Pécs , Hungary.
Balázs
B
Sági
Second Department of Medicine and Nephrological Center, Faculty of Medicine , University of Pécs, Pécs , Hungary.
István
I
Wittmann
Second Department of Medicine and Nephrological Center, Faculty of Medicine , University of Pécs, Pécs , Hungary.
Judit
J
Nagy
IgA nephropathy; cardiovascular risk factors; chronic kidney disease progression; end-stage renal disease; metabolic syndrome