By Joy Stephenson-Laws, JD, Founder

If you’re like most people, you know your key health numbers such as blood pressure, weight, cholesterol and even A1C. But there are two other numbers that you may not be as familiar with even though they are equally important for keeping you healthy. These are your glomerular filtration rate and albumin-to-creatinine ratio. Since they are a mouthful, they are usually referred to by the acronyms GFR and ACR, respectively. And both relate to your kidney health.

One third of American adults are at risk for kidney disease. Since early kidney disease often has no symptoms, these numbers can tell you if you’re at risk for kidney disease, if you already have it and, if you do, how far along it has progressed. The good news is that early detection and intervention can often prevent serious kidney disease or keep it from progressing.

Your healthcare provider will probably include determining your GFR and ACR as part of your routine annual physical blood work. These tests may also be administered if you have conditions that could increase your risk of kidney disease, such as high blood pressure, diabetes, blood in your urine, painful urination or the need to urinate frequently.

Your GFR and ACR

GFR measures how well your kidneys eliminate toxins from your body. The results are based on how much creatinine (a waste product your muscles create, and your body eliminates through your kidneys) is in your blood along with your age, race, sex, weight and height.

There are five stages of kidney disease, and your GFR will help your healthcare provider determine which stage you may be at. In addition, this information gives your provider objective information on which to rely and the ability to suggest the best treatment plan to keep your kidneys functioning at their best.

While any GFR over 90 is considered normal for most adults, it’s important to keep in mind that your GFR will decrease as you get older. This lowering reflects the natural reduction in your kidney function as you age. This decline happens even without any kidney disease present.  

To give you an idea of the average GFR for people of different ages, someone under 30 will have a GFR of over 110; from 30 to 39 the GFR is typically around 107; 40 to 49 sees a drop to approximately 99; for ages 50 to 59, the GFR reduces to 93; from 60 to 69, you can expect a GFR of around 85; and over 70, the GFR hovers at 75.  

In terms of the stages of kidney disease, Stage I is a GFR higher than 90 and indicates mild kidney damage with normal functioning; Stage II is a GFR between 60 – 89 and indicates mild loss of kidney function; Stage III is between 45 – 59 and shows mild to moderate loss; Stage IV is between 30 – 44 and indicates moderate to severe loss of kidney function; Stage V is a GFR between 15 to 29 and means severe loss; and Stage VI is a GFR of less than 15 and indicates kidney failure.

While your GFR is based on how much creatinine is in your blood, your ACR is based on how much albumin (protein) is in your urine. If you have too much albumin in your urine, it could mean that your kidneys are not filtering your blood well enough. Once the ACR test is done, your healthcare provider may look to see whether the amount of albumin in your urine is higher than the normal level of about 30 mg/g. If it is above this amount, it could be a sign of kidney disease even if your GFR is in the normal range for your age.

Depending on your GFR, ACR and other risk factors, your healthcare provider may also recommend other tests to get a better idea of how your kidneys are functioning and what types of treatment, including lifestyle changes, may be appropriate. These include imaging tests such as an ultrasound to get a visual picture of your kidneys, which will help your healthcare provider “see” the size of your kidneys and if you have kidney stones or other obstructions. In some situations, your doctor may want to do a biopsy to allow actual kidney tissue to be examined and analyzed.  

Being Proactive

If any of your tests show that you have some degree of kidney disease, your doctor may focus on treating the underlying condition that may be causing any loss of kidney function or increasing your risk for kidney disease progression.

For example, you may be prescribed medication and lifestyle changes to better treat and manage high blood pressure, reduce your cholesterol levels or better ways to manage prediabetes or diabetes.  

Since medications or nutritional supplements you take generally pass through your kidneys, it’s also important to be aware of the risks they may pose to your kidney health and to work with your healthcare provider to minimize these risks. Some things to be especially careful of are:

• OTC Analgesics such as ibuprofen, aspirin, acetaminophen and naproxen sodium
• Antibiotics such as tetracyclines, penicillin and amphotericin B and gentamicin
• Supplements, especially vitamin C, which can also increase your risk for kidney stones
• Bowel/Colon medications such as prescription laxatives (used before colonoscopies)
• Contrast dyes sometimes used during imaging tests

 You can also do your part to reduce the risks of kidney disease by following a healthy lifestyle that reduces the risk factors, such as high blood pressure, of developing kidney disease. This includes:

• Maintaining a healthy weight for your age and sex
• Following a heart-healthy diet rich in fresh fruits and vegetables and eliminating added sugars and processed foods
• Limiting your alcohol intake
• Not smoking or quitting smoking if you still smoke

 It’s also very important to make sure that you stay hydrated by drinking enough water. This will help keep your kidneys functioning at their best as well as make it less likely that you will develop kidney stones. While the general rule-of-thumb is to drink eight glasses of water a day, your own needs may be different depending on a lot of factors. These include the climate where you live, your level of physical activity and any chronic diseases you may have.  

But equally as important as staying hydrated is maintaining the correct balance between extracellular water (the water that is outside your cells) and intracellular water (the water located inside your cells). Extracellular water - or ECW – is about a third of the total fluid in your body; intracellular water – or ICW – makes up the rest.  

The balance between these two plays a role in keeping your kidneys healthy, since an imbalance can increase your risk of health problems, including kidney disease. An increase in ECW, for example, can make your kidneys work overtime to reduce the swelling than excess ICW can cause. This strain, over time, can contribute to renal failure. One great way to determine the balance between your ECW and ICW, as well as other physical measurements that can impact your kidneys, is to have an InBody test.  

Knowing your kidney numbers is as easy as seeing your healthcare provider for a simple blood and urine test. The half hour you invest in doing so may help ensure that your kidneys remain their healthiest for years to come.

Enjoy your healthy life!

The pH professional health care team includes recognized experts from a variety of health care and related disciplines, including physicians, attorneys, nutritionists, nurses and certified fitness instructors. This team also includes the members of the pH Medical Advisory Board, which constantly monitors all pH programs, products and services. To learn more about the pH Medical Advisory Board, click here.