How diabetes affects your whole body
When diabetes is not well controlled, the sugar level in your blood goes too high. This is called hyperglycemia. High blood sugar can cause damage to many parts of your body, especially:
- blood vessels
Diabetes is the leading cause of kidney disease. Kidney disease due to diabetes is called diabetic kidney disease. Diabetes can also cause high blood pressure and hardening of the arteries, known as arteriosclerosis. These can lead to heart and blood vessel disease.
How diabetes harms your kidneys
Diabetes can harm your kidneys by causing damage to blood vessels, nerves and the urinary tract.
- Blood vessels in your kidneys
- Nerves in your body
- Urinary tract
The filtering units of the kidney are filled with tiny blood vessels. Over time, high blood sugar levels can cause these vessels to become narrow and clogged. Without enough blood, the kidneys become damaged and a type of protein called albumin passes through these filters and into the urine. This is known as albuminuria and is an early sign of kidney damage.
Nerves carry messages between your brain and all other parts of your body, including your bladder. They let your brain know when your bladder is full. But if the nerves of the bladder are damaged because of diabetes, you may not be able to feel when your bladder is full. The pressure from a full bladder can damage your kidneys.
If urine stays in your bladder for a long time, you may get a urinary tract infection due to bacteria (organisms that can cause infection). Bacteria grow very fast in urine with a high sugar level. Most often these infections affect the bladder, but they can sometimes spread to the kidneys.
Not all kidney damage is caused by diabetes. Other diseases can be involved. If the cause of your kidney damage is not known a kidney biopsy can help your healthcare professional find the cause.
Managing blood sugar
Besides your kidneys, diabetes can cause serious damage to your heart, blood vessels, eyes, feet, and nerves. The best way to protect them is by controlling your blood sugar. This is usually done with diet, exercise, and, if needed, insulin shots or hypoglycemic pills. The dose of insulin must often change when people go on dialysis or get a new kidney transplant.
To manage blood sugar, you will also need to:
- Test A1C regularly
- Use a blood glucose meter
- Safeguard against low blood sugar
Your A1C test tells you what your average blood sugar has been for the past 2–3 months. You should be tested twice a year if your diabetes is under control. Otherwise you should be tested every three months. For most people with diabetes, the result should be around 7 percent. Depending on your overall health, a slightly higher level may be okay in some circumstances. Ask your healthcare professional what your test result should be. Stay on goal. It will help protect your heart, blood vessels, eyes, feet, and nerves.
You must also check your blood sugar levels every day. You can do this test at home with a blood glucose meter. The test is usually done several times a day. It tells you what your blood sugar is at any moment. Patients on peritoneal dialysis using icodextrin should check with their peritoneal dialysis team to see what blood glucose meter they should use for the best test results.
Most people know that high blood sugar is dangerous. But low blood sugar (called hypoglycemia) can be dangerous as well. Your risk of low blood sugar is higher if you are on dialysis, especially if you have trouble eating, are often sick to your stomach or have other digestive problems. Tell your dialysis healthcare team if you have any of these symptoms.
Controlling High Blood Pressure
Your blood pressure will be a little higher before your dialysis treatment than it is after treatment. This happens because dialysis replaces the work of your failed kidneys. It cleans your blood of harmful wastes and helps lower blood pressure. Blood pressure goals are not the same for everyone. Yours will depend on your age and other factors.
You must check your blood pressure as often as your dialysis healthcare team recommends. You may also need medicine to control your blood pressure. For some people, more than one high blood pressure medicine may be needed. Studies show that the use of these medicines may help reduce heart disease in people with diabetes. Your dialysis healthcare team may also have you:
- Drink less fluid
- Eat less salt
- Have longer dialysis treatments
- Have more than three dialysis treatments per week
- Take blood pressure medicine at night rather than during the day
Managing cholesterol and blood lipids
Many people with diabetes and kidney failure have high levels of blood lipids. Lipids are fatty substances like cholesterol. High blood lipid levels can cause the blood vessels to become clogged. This lessens the blood supply to the heart and brain and raises your chance of having a heart attack or stroke. Your healthcare professional will check your cholesterol and lipids at least once a year. If they are too high, you may need drugs to help lower them.
Getting tested for heart and blood vessel disease
Heart and blood vessel problems are common in people with both diabetes and kidney failure. In fact, half of all dialysis patients will die of heart disease. You should be tested when you first start on dialysis, and at least once every year afterwards.
Managing your diet
There are special dietary needs for people with diabetes who are also on dialysis. For example, you may need more protein than what is normally recommended for people with diabetes. You may also need to limit certain nutrients such as sodium, potassium and phosphorus. You should talk to your healthcare professional about this. Do not change your diabetes diet without first talking to a dietitian who specializes in kidney disease so that you have a healthy approach to dietary changes.
Other Key points to remember about diabetes and kidney failure
- Get regular exercise.
- Keep body weight under control.
- Diet is a very important part of the treatment of all patients with diabetes and kidney disease.
- Ask your dietitian to help you create a meal plan that includes healthy food choices. Eating wisely will help you control blood sugar, blood pressure, cholesterol, and mineral and bone disorder.
- If prescribed, take medicines to help you control your blood sugar, blood pressure, cholesterol, anemia, and bone and mineral disorder.
- If you smoke, ask your doctor about a plan to help you quit. If you don't smoke, don't start.
© 2015 National Kidney Foundation. All rights reserved. This material does not constitute medical advice. It is intended for informational purposes only. Please consult a physician for specific treatment recommendations.