Microalbuminuria post-renal transplantation: relation to cardiovascular risk factors and C-reactive protein

Microalbuminuria predicts graft loss and all-cause mortality in renal transplant recipients. In the general population, it clusters with both cardiovascular risk factors and elevated C-reactive protein (CRP). Our objective was to define the relationship between microalbuminuria and these risk factors in stable renal transplant recipients. We identified 222 stable recipients who were minimum two months post-transplant and provided three urine albumin-to-creatinine ratio (ACR) measurements, excluding those with recent illness and proteinuria. Microalbuminuria was defined as averaged ACR >= 2.0 in men and 2.8 mg/mmol in women (Canadian Diabetes Association 2003). Risk factors associated with microalbuminuria were determined by multivariate logistic regression analysis. Averaged ACR correlated to CRP (R = 0.21, p = 0.001). Prevalence of microalbuminuria was 48% (108/222). Patients with microalbuminuria had higher CRP (7.01 +/- 8 vs. 3.21 +/- 3 mg/L, p < 0.0001) and systolic BP (129 +/- 17 vs. 123 +/- 12 mmHg, p = 0.004). Microalbuminuria was associated with increasing CRP [odds ratio 1.129 per 1 mg/L (95% CI 1.058-1.204), p = 0.0002], SBP [1.248 per 10 mmHg (1.023-1.522), p = 0.029] and smoking [1.938 (1.023-3.672), p = 0.042]. Post-transplant microalbuminuria is prevalent and is associated with elevated CRP, elevated BP, and smoking. Its relationship to these factors suggests it may be an indicator of graft and patient health.