Pathophysiology of Diabetic Nephropathy-What causes nephropathy!

As we know, diabetic nephropathy occurs when the kidneys do not function properly on a microvascular level. We already know it is caused by diabetes, but it is is due to a variety of factors on a microscopic level. Mainly, hypertension and hyperglycemia damages the glomerulus (a functional unit of the kidney) is under a lot of pressure to filter the blood. This is a hemodynamic change of the glomerular hyperperfusion and hyperfiltration, resulting in microalbuminuria. 

What do all theses words mean?

Hemodynamic is of or relating to the flow of blood within the body system. 

Hyperperfusion means an increase of blood flow. 

Hyperfiltration is an increase of an abnormal increase in filtration. 

Continuing on....

The glomerulus is under a lot of stress, and eventually leaks albumin from the capillaries. Albumin is a major protein found in the blood and we don't want lose it! It's important.  If that is excreted out of the body, instead of kept, it can lead to the glomerular basement membrane thickening. The thickening of the basement membrane slow down the filtration rate since there's less room for the blood to bypass. This will also increase the levels of albumin when excreted in the urine (microalbuminiuria). 

Below is a complicated image that gives you an image of increase hypertension to the glomerular, leads to mesangial expansion, thickening of the glomerular basement membrane (GBM), and podocyte injury (podocypathy). Podocyte is a fucntion unit of the kidney that helps filtrate the blood. The basement membrane is composed of mesangial cells, that make up bowman's capsule of the glomerulus. When all these various functional units are affected, it leads to dysfunction.

Image from Nature.com. Link below. http://www.nature.com/nrneph/journal/v10/n2/images_article/nrneph.2013.272-f1.jpg

Furthermore, the mesangial cells that hold the capillaries in the glomerulus together, respond to injury by releasing cytokines. Cytokines lead to inflammation and mesangial cell expansion. In diabetic nephropathy, mesangial cells respond with increased pressure and injury that is caused by high blood glucose. This later can cause kidney failure leading to ERSD (previous mentioned earlier posts). This is definitely not good so we will talk about how you can diagnose this disease!

Here's a video link for those who are interested!

Next week, we will discuss how you diagnose the disease!

Citations:

1. Bakris, G. (n.d.). Recognition, Pathogenesis, and Treatment of Different Stages of Nephropathy in Patients With Type 2 Diabetes Mellitus. Mayo Clinic Proceedings, 444-456. Retrieved January 25, 2015.

2. Schena, F. (2005). Pathogenetic Mechanisms of Diabetic Nephropathy.Journal of the American Society of Nephrology, S30-S33.

3. Diabetic Nephropathy. (2000, January 1). Retrieved January 25, 2015, from http://journal.diabetes.org/clinicaldiabetes/v18n12000/Pg7.htm

4. Lewis, S. (2014). Medical-surgical nursing: Assessment and management of clinical problems. (8th ed.). St. Louis, Mo.: Elsevier/Mosby.

5. Plasma. (n.d.). Retrieved January 25, 2015, from http://www.redcrossblood.org/learn-about-blood/blood-components/plasma

6. (n.d.). Retrieved January 25, 2015, from http://www.rjme.ro/RJME/resources/files/530112023027.pdf