The beginning of the diabetic nephropathy in humans is related out to the abundance of proteins like albumin fluxing out through the urine as consequence of the permanent filtering of these negatively charged giant proteins that can escape from the micro vessels inside of the renal glomerulus mainly due to the presence of large densities of glucose in the blood. An indicator that is used by the nephrologist is known as the Albumin Excretion Rate (AER). In this paper we perform numerical estimates of this indicator by using the Feynman-Kac formula by which the flux of albumin is seen from the angle of propagation instead of diffusion. Since this anomalous flux out of albumin is seen as a stochastic dynamics so that the theory of random paths and the Feynman propagator would fit to model the very beginning of the diabetic nephropathy. We present numerical estimates that are compared with clinic data in order to validate the present approach.