Diabetic Nephropathy

Keeping blood glucose concentration constant in the body relies in the interaction between glucagon and insulin. Sadly for over 300 million people in the world this system of control fails to work properly. Diabetes Mellitus is caused by bodies inability to metabolise carbohydrates; in particularly glucose. 

Types of diabetes 

Hyperglycemia(abnormally raised blood glucose concentration) is a common effect of uncontrolled diabetes. It is caused by the bodies inability to produce insulin or respond effectively to the insulin produced. Over long periods of time, high blood glucose concentrations can lead to serious damage of body systems; including nerves and blood vessels.

Type 1 diabetes, previously known as "Insulin Dependent diabetes" or "Childhood onset diabetes", is caused by our bodies inability to produce insulin. Within our pancreas, inside the exocrine glandular tissue is a small region of endocrine glandular tissue known as Islets of Langerhans  (responsible for producing insulin and glucagon). The Beta-cells sub-section within the Islets of Langerhan, B-cells, responsible for producing insulin fails to produce insulin causing type 1 diabetes. Evidence suggests this happens as a result of an autoimmune response where the body's own immune system attacks the B-Cells. But this cannot be confirmed and the initial cause is not yet fully known. Despite the fact symptoms can be treated, type 1 diabetes cannot be prevented or cured. 

Type 2 diabetes(T2D) happens as a result of our body not being able to use insulin effectively in order to control blood sugar levels. This happens as a result of our body not producing sufficient amounts of insulin or due to the person's body cells not responding to insulin(cells lose responsiveness to insulin, and are not able to take up glucose -leaving it in the bloodstream due to glycoprotien insulin receptors on cell membranes not working properly). On average 90% of people with diabetes have type 2 diabetes. This is mainly due to  excess body weight, habitual, excessive overeating of refined carbohydrates, and lack of physical activity. Symptoms of TD2 are similar to those of Type 1 diabetes, but develop less slowly and less severely - resulting in the disease being diagnosed after complications have already arisen. 

Treatments 

People who have type 1 diabetes use insulin to control and manage their blood glucose levels; hence why it's also known as Insulin dependent Diabetes. Regular testing of blood glucose concentration by pricking finger on a machine tells a person of the concentration of glucose within their blood. This information is then used by diabetics to work out of the dose of insulin they need to inject. Administrating insulin causes glucose to be absorbed by cells and further causes glycogenesis- excess glucose converted and stored as glycogen in the liver, lowering blood glucose levels. 

Type 2 diabetes treatment involves a persons dietary intake with sufficient levels of exercise to counterbalance energy consumption. Overweight diabetics are further encouraged to lose weight.  In addition to exercise and regulating ones carbohydrate intake, in some cases drugs are used to stimulate insulin production and slow down the rate at which glucose is absorbed into our intestines. 

Diabetic Nephropathy

Figure 1

Diabetic Nephropathy is kidney damage caused by both type 1 and type 2 diabetes. It is the leading factor for kidney failure - end stage renal disease globally. It is also said to effect 30% of  all individuals with diabetes around the world. 
Each kidney is made out of nephrons(figure 1). 1,000,000 nephrons to be precise. These microscopic structures are the functional unit of a kidney - producing urine in the process of removing wasteful substances in the blood.  A nephron consists of a capillary bed known as the Glomerulus , an arteriole that approaches the glomerulus known as the Afferent Arteriole, and an arteriole that exists the glomerulus known as the Efferent Arteriole.  The glomeruli are a bundle of capillaries that are beneath supported by cells known as the Mesangial cells. 

When blood is filtered it moves through the lining of the endothelium lining of the Glomerulus Capillary, then through the basement of the membrane and  then through the epithelium lining the nephron, and finialy into the nephron itself where is it known as "filtrate". The endothelium of the Glomerulus has permeable pores that prevent cells (like red blood cells) passing through the epithelium and entering the neprhon. Furthermore the basement of the endothelium is negatively charged;repelling any negatively charged molecules and protiens trying to leave the Glormerulus, like the protein albumin.  The high concentration of glucose in the blood of diabetics results in blood being filtered in the kidneys "spilling" glucose through the endothelium, and into the "filtrate" ... AKA urine. This process is known as Glycosuria.  Furthermore the high concentration of glucose in the blood results in covelant bonds being formed from the glucose molecules to the albumin protien molecules. A process known as Non-Enzymatic-Glycation.  

As high concentration of glucose causes the molecules to get through the membrane, also means the glucose molecules enter the efferent arteriole of the Glormerulus making it thicken and narrow. This disrupts the blood flow of the efferent arteriole and causes hypertension. While the efferent arteriole becomes narrower and thickens, the afferent arteriole dilates and allows more blood to flow into glormerulus increasing the pressure further. High pressure in the glormerulus further increases the filtration rate (increasing the amount of blood filtered through per minute). This process is known as Hyperfilteration. 

As a result of hypertension, the supportive mesangil cells that make up the glormerulus increase in numbers which allows the glormerulus to expand and increase in size. The increase in size of the glormerulus increases the size of of the basement membrane also, inturn increasing its permeability. 

This means portiens such as albumin can easily pass through the membrane into the urine, explaining why the presence of protein in urine dictates problems with kidney function. Tests for identifying kidney decline consists of monitoring the presence of albumin in the urine. 

To summarise, diabetic nephropathy results in thickened glomerulus basement membrane, which results in mesangil expansion which in-turn leads to less permeable endothileum membranes, and causes waste products in kidney to pass into the urine, and over time decreasing the kidneys normal function. Thus, the high concentration of glucose in blood as a cause of diabetes leads to the decrease of kidney function over an extend period of time.

This article was an attempt to make our readers more aware of the interrelated health issues that diseases such as diabetes may have on other body systems. It is often taken for granted the fortune of good health we possess. Take time to remember your health is a gift, and be grateful.

Thank you for reading. Universal Medicine team (Mathew George)