Nephropathy means kidney disease or damage. It is the leading cause of kidney failure in Canada and the Western world – and affects up to 50% of people with diabetes during their lifetime.
The role of the kidneys
The kidneys act as a filtration system. Through urine, they eliminate products that the body doesn’t need or that are in excess in the blood, such as sodium, potassium, urea, albumin (a type of protein), glucose and water.
High blood sugar levels force the kidneys to work hard to eliminate excess sugar through the urine. That’s why optimal blood sugar management is essential.
The primary risk factors
- Living with diabetes for a long time;
- Have frequently high blood sugar levels;
- High blood pressure;
- High blood cholesterol levels;
- Have a body mass index (BMI) equal to or greater than 30 ;
- Smoking;
- Being male.
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).
Symptoms
Kidney disease is insidious, as symptoms only appear at a very advanced stage of the disease. When the kidneys are on the verge of ceasing to function (end-stage renal disease or stage 5), symptoms such as fatigue, weakness, nausea and vomiting, swelling, loss of appetite and generalized itching may appear.
Screening
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.
Screening is carried out by means of blood and urine tests. When the kidneys begin to function less well, they release elements the body needs, such as proteins, into the urine. Although invisible to the naked eye, it is possible to measure the level of these proteins by performing a urine analysis. The screening test is completed by a blood test to assess the kidneys filtration capacity (creatinine, glomerular filtration rate).
Treatment
Kidney damage caused by nephropathy is irreversible, i.e. it cannot be cured. This is why it is so important to detect abnormal kidney function as early as possible. In fact, it is possible to prevent and slow the progression of kidney disease through medication and lifestyle habits, such as rigorous management of hypertension and blood sugar levels:
- Dietary recommendations: A balanced diet for diabetes management is also adapted to protect your kidneys. It may also be necessary to limit protein and sodium (salt) intake. The body’s digestion of proteins produces “waste products” that the kidneys must eliminate. Limiting protein intake can therefore ease the burden on damaged kidneys. A nutritionist can teach you how to control your protein and sodium intake and, if necessary, certain other minerals (calcium, phosphorus and potassium).
- Smoking cessation
- Medication: several drug treatment options are available.
- To improve blood pressure:
- Angiotensin-converting enzyme (ACE) inhibitors: enalapril, perindopril, ramipril
- Angiotensin II receptor blockers (ARBs): candesartan, irbesartan, losartan, olmesartan, telmisartan, valsartan
- To slow the progression of kidney disease: finerenone (Kerendia®).
- Some drugs have the dual function of improving blood sugar levels and protecting the kidneys and heart:
- SGLT2 inhibitors: canagliflozin (Invokana®), empagliflozin (Jardiance®), dapagliflozin (Forxiga®).
- To improve blood pressure:
- Dialysis or transplantation: Unfortunately, diabetic kidney disease can continue to progress despite the adoption of appropriate behaviours. In the case of end-stage renal failure (stage 5), when kidney function is less than 15%, dialysis should be considered to replace impaired renal function and clean the blood. Kidney transplantation may also be an option.
A specialized dialysis team
A team made up of a nephrologist, a registered dietitian, a nurse, a pharmacist and a social worker can help you deal with kidney disease and the complications of kidney failure, and slow its progression. If necessary, they can inform and support you in your choice of renal replacement therapy.
Helpful resources
Documents
- Kidney Health and diabetes (also available in the shop)