Podocyturia: an earlier biomarker of cardiovascular outcomes

Abstract

Urinary podocin and nephrin mRNAs (podocyturia), as candidate biomarkers of endothelial/podocyte injury, were measured by quantitative PCR in Type II diabetics with normal albumin excretion rates (AER) at baseline, at 3–4 years, and at 7 years. Development of cardiovascular disease (CVD) was collected as outcome. Visit 1 podocyturia was significantly higher in subjects who subsequently developed CVD versus those who did not. Visit 1 AER terciles exhibited similar time to CVD, in contrast with stepwise and substantial increases in CVD events predicted by Visit 1 podocyturia terciles. Covariate-adjusted hazard ratios were highest for podocin, intermediate for nephrin mRNAs, and lowest for AER. Podocyturia was also measured in patients with and without significant coronary obstruction, and in 480 normoalbuminuric subjects at the enrolment visit to the Multi-Ethnic Study of Atherosclerosis (MESA). Podocyturia > 3 × 106 copies was associated with presence of obstructive coronary artery disease. In the MESA population, Visit 1 podocyturia was significantly higher in men, subjects with elevated BMI, and those with Type II DM. Conclusions: Podocyturia may be an earlier predictor of cardiovascular events than moderate albuminuria; it is significantly higher in patients with obstructive coronary artery disease, and in subjects with established risk factors for CVD.