The Kidney TRUST

Kidney Disease and Your Heart: The Hidden Link Part 2

Part 1 of this two-part article which appeared in the October 2008 edition of eNEWS focuses on heart disease.

Adding Diabetes into the Mix

If you have diabetes, you may be used to thinking of it as a blood sugar disease.  It is, but it’s also much more than that.  Diabetes affects the blood vessels—it is truly a vascular disease.  This means that poor blood sugar control can harm your heart and your kidneys by causing damage to your blood vessels.


Type 1 and type 2 diabetes have different causes, but affect your body in the same way.  Type 1 diabetes is an autoimmune disease.  The immune system attacks the pancreas, and the islet cells that make insulin are destroyed.   With type 2 diabetes two things can happen.  The islet cells may make less insulin than the body needs, or make enough insulin but the cells are unable to use it.   What’s common to both?  Too much sugar in your blood vessels, which can damage them.

Most people have two kidneys, and each one has about one million nephrons which are tiny filters.  These filters pull wastes and extra water out of the blood and send them to your bladder as urine.  By damaging blood vessels, high blood sugar can ultimately destroy nephrons so that protein leaks out and waste products are no longer appropriately filtered.   In time, so many nephrons may be destroyed that the kidneys fail and dialysis or a kidney transplant are required to sustain life.

Diabetes and High Blood Pressure – A Double Whammy

Too much sugar in the blood vessels plus high blood pressure is a double whammy on the kidneys.  Diabetes is the number one cause of kidney failure, while high blood pressure is the second.  Having both diabetes and high blood pressure makes chronic kidney disease (CKD) progress much faster than having either condition on its own.

The American Diabetes Association says that two out of three people with diabetes die from heart disease and stroke.  Why?  Because as many as 70% of those with diabetes have high blood pressure, too.

Nine out of ten people with type 2 diabetes are overweight.  Weight gain in general is also strongly linked with high blood pressure, although the reasons for this are not yet clear.  A high-salt diet, which is common even among healthy Americans, can raise blood pressure.

What You Can Do

Kidney damage doesn’t have to happen if you have diabetes—even when you also have high blood pressure.  Taking steps and controlling these conditions will reduce your risk and have big payoffs for your health.

Tight diabetes control means keeping blood sugar close to normal all the time.  This has been shown in a large, long-term study to vastly reduce the risk of problems with the kidneys and the eyes.  Tight control is done with diet, exercise, and insulin for those who need it.  Testing blood sugar often helps you learn what makes your sugars go up.  Dr. Richard Bernstein, who has had type 1 diabetes for more than 55 years, offers a diet approach that has helped him avoid or even reverse some long-term problems.

Blood pressure also can be kept in control with exercise, diet, and medication.   Just walking for 20 to 30 minutes a day can help.  A diet rich in non-starchy vegetables and some fruits can help reduce blood pressure and improve your blood sugar control.  If you are overweight, losing weight can also help both health problems.  Keeping your blood vessels healthy will help your whole body to work better.