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Diabetic Nephropathy

Jul 2, 2004

Author: Dr. Brian P. Jakes

Diabetic nephropathy is the dysfunction of the kidneys that is seen in both types of diabetes, but seems to be more common in Type I patients.

It is a vascular complication that affects the tiny glomerular capillaries of the kidney thus reducing the kidney’s filtration ability. This is first indicated by the appearance of protein in the urine.


It is a vascular complication that affects the tiny glomerular capillaries of the kidney thus reducing the kidney’s filtration ability. This is first indicated by the appearance of protein in the urine.

Typically before any signs of nephropathy appear, retinopathy has usually been diagnosed. Retinopathy is also a microvascular complication that causes similar damage to the blood vessels in the retina and lens of the eye.

There are several different theories on the mechanisms involved in the development of these conditions, however they all are based on chronic hyperglycemia.

The presence of glucose alone is harmless until an enzyme called aldose reductase catalyzes it. The result is the production of sorbitol, a converted sugar alcohol. Sorbitol itself is not a problem but the amount of sorbitol present in a given organ or cell is. The kidneys have several different types of cells containing aldose reductase. A patient with elevated serum glucose levels would likely produce more sorbitol in these sites. This causes a fluid imbalance within these cells and this disruption of cellular osmoregulation might corrupt sufficient cell function to cause organ impairment and failure.

This process is known as the polyol pathway. The other manifestations associated with the polyol pathway and nephropathy are increased permeability and thickening of glomerular basement membranes that will eventually decrease renal function.

There are a number of physiological changes at the onset of diabetes and during the course of the disease. These changes begin with an enlargement of the kidneys. This may be reversible if near normal blood glucose values are restored promptly and then maintained. Also, an increase in glomerular filtration rate and renal plasma flow are common in almost half of patients, signaling some of the indications of altered renal function. These signs will go unnoticed for years while the kidneys’ efficiency continuously decreases and then dramatically declines towards end stage renal failure.

Screening for elevated levels of protein seepage in the form of albumin or more specifically micro albumin in the urine will confirm renal involvement. Routine diagnostic micro albumin Testing is the best way to monitor and identify renal problems.

It appears that the damage incurred in the kidneys from the effects of sustained hyperglycemia is cumulative throughout the duration of diabetes. Improvements in blood sugar control at anytime will help to slow or even prevent this complication from occurring. The strategies outlined in this article to reduce glycosylation and support blood vessel integrity and flow may be some of the best defenses.

There are a large number of studies that suggest the use of antioxidants indirectly helps in the prevention or improvement of diabetic nephropathy.[i]

Although there are a number of supplements that may improve nephropathy, inositol has shown direct benefits.

There is a depletion of intracellular inositol during hyperglycemia possibly leading to cell corruption. Oral supplementation of inositol, a member of the B vitamin group, may help correct this situation. As mentioned earlier, there are similarities between retinopathy and nephropathy in the case of diabetes. The common feature of both conditions is damage to the tiny blood vessels located in the eyes and the kidneys. An extract of the bilberry plant has been studied in-depth for well over half a century and has proven its ability to increase vascular integrity within the eye, so it use as a prophylactic agent in nephropathy should be strongly considered.

Animal research with bilberry and its effect in the kidneys as well as for hypertension, give cause to believe that it will be equally effective in treating nephropathy.

Vitamin C may also be beneficial in the treatment and prevention of nephropathy through several pathways.

Vitamin C acts as an aldose reductase inhibitor reducing sorbitol conversion and decreasing cellular damage in the kidneys.

Vitamin C may also be helpful is this role as an antioxidant. Hyperglycemia induces oxidative stress that negatively effects the vascular system and can lead to the development of atherosclerosis. Patients with nephropathy show lower serum levels of vitamin C due to increased renal clearance of vitamin C.[iii] This reduction may allow more oxidant damage to occur to the vascular system and kidneys thus perpetrating the cycle.

Animal studies with vitamin E have been used with success in preventing glomerular dysfunction. Recent studies with diabetes patients show a significant improvement in renal function with high dose vitamin E.

Normalization of blood lipids and cholesterol are important in the prevention of diabetic nephropathy.

Reducing high blood pressure will aid in preservation of renal function.

Diet and exercise must not be excluded in the treatment of nephropathy. Dietary restriction, but not exclusion of, protein, sodium and some types of fats may also help delay renal failure.

The reduction of dietary protein will also cause a similar decrease in amino acid intake and conversion. This may facilitate the need for oral amino acid supplements. Saturated fats should be replaced ideally with monounsaturated fats like those in fish or chicken. [ix]

Angiotensin converting enzyme (ACE) inhibitors are drugs used after the diagnosis of nephropathy. Some recent studies have shown the benefit of starting all diabetes patients on these types of drugs.

They treat some of the symptoms of nephropathy, but like all drugs of this nature they have significant side effects that must be monitored closely especially if the patient is close to end stage renal failure.

Dr. Brian P. Jakes, Jr., N.D., C.N.C.  is a Board Certified Doctor of Naturopathy as well as a Certified Nutritional Consultant. In his practice, in Mandeville, LA, Dr. Jakes works with physicians to treat a large number of diabetes patients. This is an excerpt from his upcoming book; “Diabetes: The Essence Of A Cure”