Diabetic nephropathy is a complication of diabetes that damages the blood vessels (capillaries) in the kidneys and can lead to kidney failure. Blood circulating through a network of capillaries (glomerulus) in the kidneys is filtered to remove the toxins and form urine. The high blood glucose levels in diabetics damages the walls of these capillaries and thereby affects blood filtration by the kidney. It is more likely to arise in the elderly who have suffered with diabetes mellitus (sugar diabetes) over years and decades, especially when the diabetes was poorly controlled.
Patients do not show any symptoms in the early stages of diabetic nephropathy. A blood protein known as albumin routinely detected in the urine is the first sign of damage to the kidneys. Subsequently, blood pressure and fat (triglycerides and cholesterol) levels in the blood rise. The legs and feet might also become swollen as the kidney functions deteriorate further. In the last stage, kidney failure may occur.
Since the patients do not show any symptoms in the beginning, regular urine tests and kidney function tests are recommended for diabetics in order to detect the disease at the earliest stage and begin treatment. Early treatment can successfully delay or prevent the onset of diabetic nephropathy.
The exact reason for diabetic nephropathy is not known. Increased blood glucose level in diabetics is thought to stimulate production of certain signaling molecules that are responsible for the changes in blood vessel structure and function. These blood vessels carry blood close to the functional filtration unit of the kidney – the nephron. First, fluid passes into the glomerulus (head of the nephron) and as it passes through the nephron tubules it is made into urine.
High blood pressure and high blood cholesterol are also risk factors in the development of diabetic nephropathy. Genetics might also influence the development of diabetic nephropathy because certain ethnic groups (African-Americans, Hispanics, and American-Indians) seem to be at higher risk of developing this renal disease. Apart from these other risk factors, it is the long term and poorly controlled diabetes that is the main contributing factor.
The primary aim of the treatment in diabetic retinopathy is to normalize blood pressure and blood glucose level.
In case of kidney failure during the last stage of diabetic nephropathy, dialysis and kidney transplant are the only viable options. Both these procedures are renal-replacement therapies which aim to provide a substitute for the affected kidneys. Kidney transplantation is the preferred option when there is an available donor since patient recovery is much better. However, dialysis will have to suffice for most patients.