The role of the kidneys
The kidneys act as a filtration system. Through the urine, they eliminate wastes or products that are in too high a concentration in the blood, such as sodium, potassium, urea, albumin (a type of protein), glucose and water. The kidneys are of paramount importance for our health.
A person with diabetes whose blood sugar levels are poorly controlled is forcing her kidneys to work hard to eliminate the excess sugar via the urine. That is why optimal blood glucose (sugar) control is essential.
The primary risk factors for diabetic nephropathy
- Long-term diabetes
- Poor blood sugar control
- High blood pressure (hypertension)
- Being male (men have a higher risk)
The sometimes slow progression of diabetic nephropathy is often associated with other vascular diabetes complications, such as of the eye (retina) and legs (lower extremities).
In the first stage of kidney disease, there are often no symptoms. In its advanced stages, diabetic nephropathy can lead to disorders related to kidney failure, the most common being:
- fatigue, weakness
- loss of appetite or weight
- swelling of the eyelids, hands and feet
- nausea, vomiting
- generalized itchiness
For adults with type 1 diabetes, screening should be done five years after the onset of diabetes, then annually thereafter. For people with type 2 diabetes, a screening test should be done when the diabetes is diagnosed, then annually thereafter or as recommended by a physician.
To verify how well the kidneys are functioning, urine and blood tests are used to detect and measure the presence of a protein called albumin.
The kidney damage caused by nephropathy is irreversible. Depending on the stage of their kidney disease, some people will need to have dialysis to eliminate wastes from their bodies. More than 40% of new dialysis patients in Canada have diabetes (Canadian Diabetes Association and Diabetes Québec, 2011).
The progression of kidney disease can be slowed or even stopped by strict blood sugar and blood-pressure control. This sometimes requires taking certain medications.
A physician will determine the appropriate treatment depending on the type of diabetes and the results of the tests requested. Treatment includes dietary recommendations and prescription blood-pressure medication.
1 – Dietary recommendations: Your doctor may suggest you see a dietitian, who will teach you how to maintain a diet that restricts proteins and, if necessary, certain minerals (calcium, phosphorus, sodium, potassium). The use of proteins by the body produces “waste” that the kidneys must eliminate. Therefore, limiting protein consumption lightens the workload of damaged kidneys.
2 – Medication: Medications used to normalize blood pressure can also reduce the blood pressure in the kidneys, which helps maintain kidney function.
Unfortunately, diabetic kidney disease may continue to progress despite the adoption of appropriate measures. When kidney function drops below 15%, dialysis treatment will need to be considered in order to replace the function of deficient kidneys and purify the blood.