The kidneys are a pair of organs found towards the back of the abdomen, one on either side of the spine. The role of the kidneys is to balance fluid levels within the body, and filter waste products from the body as urine. The kidneys also regulate blood pressure, and the production of new red blood cells.
In diabetes, blood vessels in the kidneys can be damaged by high blood glucose levels, which will prevent the kidneys working normally. An early sign of kidney disease (or ‘nephropathy’) is the presence of a protein called albumin in the urine. The medical name for having high levels of albumin in the urine is ‘microalbuminuria’.
During the early stages of kidney disease, the kidneys will continue to function and there may be no symptoms. With more advanced kidney disease people may feel generally unwell, tired and nauseous, and the hands and feet may look swollen.
Protecting the Kidneys
Keeping blood glucose within the target range will help reduce the risk of developing kidney disease.
To monitor people with diabetes for kidney disease, a urine sample and a blood sample are screened at the person’s annual health check. These tests measure levels of albumin and ‘creatinine’, another substance found in high quantities in the blood if the kidneys are damaged. If the level of albumin in the urine is higher than it should be (above 2.5 mg/mmol for men, or above 3.5 mg/mmol for women), then the test will be repeated at the person’s next clinic visit. If the result remains the same, the person is likely to be offered treatment for kidney disease.
Treating Kidney Disease
Treatment for kidney disease is generally effective, if the disease is detected in the early stages. The usual first line of treatment for kidney disease is a medication called an ‘ACE inhibitor’. If these medicines are not suitable, another type of medicine (called an ‘angiotensin 2 receptor antagonist’) will be offered.
For people with diabetes who develop kidney disease, it is very important to keep blood glucose and blood pressure as well controlled as possible. Blood pressure tends to rise in people who develop kidney disease. It is important to reduce blood pressure to levels lower than would normally be aimed for in people without diabetes. It is usual to aim for a blood pressure of < 125/75 mmHg. Controlling blood pressure often requires several blood pressure lowering tablets.