There are no symptoms when diabetic kidney disease first develops. Later, the following signs of decreased kidney function are:
- Nausea and vomiting
- Itchy skin
- A metal taste in the mouth
- Swelling in the limbs and/or eyelids due to the build-up of fluid in the tissues (oedema)
Diabetic nephropathy is diagnosed using a number of tests including:
- Urine tests - to check protein levels. An abnormally high level of protein in the urine is one of the first signs of diabetic nephropathy.
- Blood pressure - regular checks for raised blood pressure are necessary. Elevated blood pressure is caused by diabetic nephropathy and also contributes to its progression.
- Blood tests - to check the degree of kidney function.
- Biopsy - a small tag of tissue is removed from the kidney, via a slender needle, and examined in a laboratory. This is usually only performed when there is doubt about whether kidney damage is due to diabetes or to another cause.
- Kidney ultrasound - enables the size of the kidneys to be imaged and allows the arteries to the kidneys to be checked for narrowing that can cause decreased kidney function
Important treatments for kidney disease are tight control of blood glucose and blood pressure. Blood pressure has a dramatic effect on the rate at which the disease progresses. Even a mild rise in blood pressure can quickly make kidney disease worsen. Four ways to lower your blood pressure are losing weight, eating less salt, avoiding alcohol and tobacco, and getting regular exercise.
When these methods fail, certain medicines may be able to lower blood pressure. There are several kinds of blood pressure drugs, however, not all are equally good for people with diabetes. Some raise blood sugar levels or mask some of the symptoms of low blood sugar. Doctors usually prefer people with diabetes to take blood pressure drugs called ACE inhibitors.
ACE inhibitors are recommended for most people with diabetes, high blood pressure and kidney disease. Recent studies suggest that ACE inhibitors, which include captopril and enalapril, slow kidney disease in addition to lowering blood pressure. In fact, these drugs are helpful even in people who do not have high blood pressure.
Another treatment some doctors use with macroalbuminuria is a low-protein diet. Protein seems to increase how hard the kidneys must work. A low-protein diet can decrease protein loss in the urine and increase protein levels in the blood. Never start a low-protein diet without talking to your health care team.