Your Glucose, Your Kidneys, And Their Unusual Connection

According to fasting glucose or A1c levels, about 38% of all adults in the U.S. are prediabetic. That’s over ⅓ of the population in this country. And the way things are headed, it’s not getting any better. With a prevalence this high, it’s important to manage your blood sugar levels before serious issues develop. 

Serious issues
When people think of blood sugar, most think of diabetes. While diabetics have to pay close attention to their blood sugar levels, this isn’t the only reason they should stay on top of it. There’s a connection between your glucose (blood sugar) and kidney function that can lead to kidney disease. Chronic kidney disease is associated with a higher risk of end-stage kidney disease, cardiovascular disease (also known as heart disease), and even death in those with type 2 diabetes! 

If you have type 2 diabetes, the prevalence of chronic kidney disease is almost 50%, so 1 out of every 2 diabetics will develop it. Additionally, common co-occurring diseases in type 2 diabetics are: high blood pressure (hypertension) at 76%, dyslipidemia (unhealthy levels of fat(s) in the blood) at 71%, and obesity at 51%. These are some sobering numbers. Luckily, managing your glucose can help decrease your risk for conditions like these. 

Blood sugar and the kidneys
We each have 2 kidneys. They’re located just below our rib cage on both sides of the spine. Your kidneys are about the size of your fist. Their job is to remove waste from the blood. When blood sugar levels go higher than 180 mg/dl, your kidneys will start to spill sugar into your urine. The higher your blood sugar goes, the more sugar comes out in your urine. If your kidneys are normal, then this usually isn’t a problem. But if you’re diabetic, high blood sugar levels can damage your kidneys over time. They damage the kidneys’ blood vessels and destroy their filters. Each kidney has millions of small filters that are called nephrons. The kidneys then can’t properly clean your blood which results in the retention of more water and salt. At the same time, waste builds up and kidney function deteriorates. When things get this bad, it results in a condition known as chronic kidney disease. Diabetes is the leading cause of it. Managing your blood sugar can decrease your risk for kidney disease. In fact, controlling your glucose can help to slow down or even stop kidney disease from becoming worse.   

Under pressure
Blood pressure is the force of your blood as it pushes against the walls of your arteries. Every time your heart beats, blood is pumped into your arteries. The heart contracts as it’s pumping blood. This is your highest blood pressure. There are 2 numbers used to measure blood pressure. The number on top is the systolic, while the number on the bottom is the diastolic. The top number occurs when the heart is in its most contracted state. The bottom number refers to the pressure inside your arteries when the heart is filling with blood and resting between beats. 

Blood pressure levels
The National Heart, Lung, and Blood Institute of the National Institutes of Health (NHLBI) put blood pressure into the following categories to make it easy to understand:

  • Normal: systolic pressure of less than 120 mm Hg & diastolic pressure of less than 80 mm Hg (less than 120/80)
  • Prehypertension: systolic pressure of 120 mm Hg – 139 mm HG & diastolic pressure of 80 mm Hg – 89 mm Hg (120/80 – 139/89)
  • Hypertension: systolic pressure of 140 mm Hg or higher & diastolic pressure of 90 mm Hg or higher (140/90 or higher)

High blood pressure does not usually cause symptoms. It’s been nicknamed the silent killer as it increases your risk for: heart disease, heart failure, stroke, etc. If it’s very high, then you might notice the following symptoms:

  • Headaches
  • Dizziness
  • Blurry vision 

Many diabetics develop high blood pressure. This can also damage the kidneys. While it’s well known that salt (sodium) can increase your blood pressure, sugar can contribute to that as well. To set the stage for how this works, let’s first talk about nitric oxide. Nitric oxide is a compound that is made by the body. It’s the end result of a conversion process, taking dietary nitrates and turning them into a useful chemical. Your body uses nitric oxide to regulate many important functions. These include the immune system, circulatory system, and exercise and muscle performance. Dietary nitrates are found in foods such as: spinach, bok choy, carrots, broccoli, eggplant, citrus fruits, garlic, etc. They are made from component parts which include vitamin C and nitrates. 

Does sugar raise blood pressure?
When you eat too much sugar, the production of nitric oxide in the blood vessels can be inhibited. Nitric oxide assists with the expansion of blood vessels (vasodilation). Without nitric oxide, your blood vessels may become narrowed (vasoconstriction). This can lead to hypertension. In this way, your glucose levels do impact your blood pressure.

What’s your glucose level?
If you’re not diabetic, then you may not know your current glucose level. This is one of those lab tests that’s helpful to have done, especially if you’re at risk for diabetes. The typical test to monitor blood sugar levels (and to detect diabetes) is based on the Hemoglobin A1c protein. In short, the higher your blood sugar gets, the more sugar attaches to this protein. A1c levels help you get an estimate of your average blood sugar levels over the past 3 months or so. This tells you how much damage sugar may be causing you.

What should you do?
Let’s talk about what you can do to keep your kidneys healthy. For one, you should keep your blood sugar levels within a healthy range. This corresponds to the normal range (below prediabetes) on my post all about blood sugar lab tests. You should have your A1c levels checked at least twice per year. If you have other health challenges or changes in any medications you’re taking, then you should have them checked more often. Talk to your doctor about what’s right for you.

Your blood sugar can impact your kidneys, your blood pressure, and result in serious and even fatal consequences if not treated. What can you do today to lower your risk for these conditions? Please tell us in the comments…