Avoid high blood pressure, diabetes to keep kidneys healthy

One of my professors in medical school, a kidney specialist, maintained that the kidney was the smartest organ in the body. No! we protested. The brain is the smartest organ! That’s your brain talking, he replied. If the kidneys could talk, they’d get the credit they were due.

For two little fist sized organs that hardly weigh a quarter pound each, they sure do a lot for us. Like most of our body’s organs, the kidneys perform more than one function. They are compact little powerhouses, and we need to treat them well.

We all know the kidneys make urine. But that is no small task. Every day the kidneys filter 200 quarts of fluid, returning 198 quarts back to the body and sending the rest to the bladder, filled with waste products the kidneys have filtered out. Each kidney contains a million little filtering plants that know what needs to go and what needs to stay.

The kidneys keep our blood at a neutral acid level. They keep bad chemicals, like ammonia, from building up to dangerous amounts. They know the right amount of calcium, and potassium, and sodium, all critical to our bodily functions. In fact, every minute of the day the kidneys are monitoring our intake of salty french fries, assessing the give and take of bone growth and destruction, and measuring how much sweat we lost at aerobics class and how much we drank when we hit the fridge.

As if that were not enough, the kidneys make important hormones that regulate our blood pressure and tell our bodies to make red blood cells so we don’t become anemic. We want to take care of them. They may be smart, as Dr. Eknoyan said, but they’re not invincible.

Diabetes, especially the more common type associated with obesity, affects more than 18 million people in the United States. Over time, diabetes can cause the filters of the kidneys to become leaky. When this happens, good things, like protein, begin to seep out into the urine. Over time, the filter can break down completely, allowing waste products to build up in the blood stream. This is end stage disease and when this happens, it’s dialysis or transplant, neither choice particularly pleasant.

One in four American adults have high blood pressure. It also affects those precious filters that keep our bodies in the delicate balance required for optimal performance. Once again, the early damage leads to leakiness, evidenced by tiny amounts of protein in the urine.

In a clever show of synergy, these conditions are often interrelated. Kidney disease can cause high blood pressure or high blood pressure can cause kidney disease. A diabetic who has high blood pressure (a common combination) is at much greater risk for kidney damage than a diabetic with normal blood pressure.

Help! What’s to be done? The best strategy is to avoid getting diabetes or high blood pressure in the first place. If weight loss, exercise, and diet changes don’t work, there are sophisticated drugs out there that can help protect the kidneys.

If you’re diabetic, the key is keeping your blood sugar tightly controlled. If high blood pressure is a problem, take your medications to keep that blood pressure lower than 130/80. Your care provider is probably checking you for microalbuminuria, tiny amounts of protein in the urine that signal the start of kidney disease. At this point the damage can be reversible.

For the rest of us who don’t think we have any problems in the sugar or blood pressure department, regular exams, including blood pressure checks and fasting blood sugar tests are part of the annual exam all of us over-40s need. Every adult, regardless of age, should have their blood pressure checked at least every two years.

Life without working kidneys is no fun. The little guys will serve you well if you do your best to keep them healthy.