Diabetes, a metabolic disorder of high blood glucose (sugar), is the major cause of kidney failure, accounting for nearly 44 percent of new cases in 2007, according to the National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC). The continually high level of glucose in the blood causes damage to both the nerves and blood vessels throughout the body, affecting the functions of organs, such as the heart, liver, skin and kidneys. Damage to the kidneys, the organs that are responsible for filtering 200 qt. of blood a day, to remove waste, according to the NKUDIC, results in a variety of complications.
Damage to Glomeruli
The kidneys are small bean-shaped organs located below the rib cage on each side of the spine. The kidneys contain small clusters of blood vessels, known as glomeruli. Glomeruli filter the blood to remove excess water and waste to be excreted as urine. Useful substances, such as protein and red blood cells, are not removed in these filters and remain in the blood to be used by the body.
People with diabetes have too much sugar in their blood. This extra sugar requires the kidneys to filter the blood more in an effort to remove it. The added stress to the glomeruli causes them to develop scar tissue and inhibits their ability to function effectively. When the glomeruli stop filtering the blood, waste products remain in the blood and can build up within the body.
Proteinuria
The damage to the glomeruli can result in protein, specifically albumin, being filtered into the urine. The presence of protein in the urine, initially referred to as microalbuminuria, is one of the first signs of kidney complications. Over time, the amount of protein that is able to pass through the filters in the kidneys increases, causing a condition called proteinuria.
Proteins in the blood help the body absorb fluids. When proteins are excreted in the urine, blood levels of protein drop and excess fluid builds up. This condition, known as edema, causes swelling of the hands, feet, abdomen or face. The presence of this symptom signals that significant kidney damage has occurred.
Autonomic Neuropathy
The autonomic nervous system is the group of nerves that send signals from the brain and spinal cord to the internal organs, including the bladder and kidneys. Diabetes can cause damage to these nerves, resulting in a condition known as autonomic neuropathy. If the nerves that supply the bladder are damaged, the bladder may not be emptied completely each time. Retaining urine in the bladder, especially diabetic urine that contains sugar, can induce the growth of bacteria. A bladder infection can quickly worsen to a urinary tract infection and lead to a kidney infection that can hinder kidney function.
