If you’ve never developed kidney stones yourself, you probably have a friend or two who have. And they are no picnic for approximately half a million Americans who visit the emergency room each year due to kidney stones.

As a person with diabetes, you definitely face a higher risk of developing kidney stones — especially if your blood sugars are chronically high.

Kidney stones can be incredibly painful, but they are also fortunately relatively easy to treat.

In this article, we’ll discuss what kidney stones are, why having diabetes increases your risk of developing them, causes and symptoms, how they are treated, and how you can prevent them from developing in the first place!

Diabetes & Kidney Stones

 

What are kidney stones?

Also referred to as “uric acid stones” or “renal stones,” kidney stones are small, hard objects that develop from chemicals in your urine, explains the National Kidney Foundation (NKF).

There are actually several different types of kidney stones and different chemicals that contribute to their development, including calcium, oxalate, urate, cystine, xanthine, and phosphate. 

In general, the formation of calcium oxalate or uric stones comes down to an imbalance: too much waste in your urine and not enough fluid. 

One purpose of our body’s need to urinate is to pass excessive amounts of chemicals, so the development of a kidney stone is a clear sign that your diet may need some improvements and/or you’re not drinking enough water.

According to the NKF, the four types of kidney stones are:

Calcium oxalate: This is the most common type of kidney stone and it develops when calcium mixes with oxalate in your urine. A diet lacking in calcium and adequate water is the number one cause of this type of kidney stone, which means it’s also easily preventable by drinking fluids and getting enough dark leafy greens in your diet! 

Uric acid: This type of kidney stone is common in people with diabetes (more on this later), as well as in those who consume a diet high in organ meats and shellfish. The high amount of purines found in those foods can lead to stones. This type of stone is also likely to “run in your family.” 

Struvite: These stones are generally a direct result of urinary tract infections. If you’re prone to developing UTIs, you may also struggle with this regularly, too. 

Cystine: The rarest type of kidney stone, these also likely “run in the family” and in people who have “cystinuria.” Cystinuria is a rare condition in which high levels of cystine (an amino acid) build-up in your urine and form crystals that become stones.

Some stones stay put in the kidney, but others may actually make its way through your urinary tract and pass without much effort or pain. If you drink adequate amounts of water, that fluid helps to constantly flush these crystals from your system.

The problem arises when those crystals continue to grow too quickly instead of being eliminated by your kidneys. Instead of passing naturally, they build-up in your kidneys or get stuck in your urinary tract and eventually create a blockage. 

This blockage prevents your body to even pass urine properly and creates tremendous pain as the urine begins to get backed-up in your kidneys, bladder, or urinary tract.

 

Symptoms of kidney stones

While you’ve likely passed smaller kidney stones and crystals throughout your life, the symptoms of kidney stones develop when the stones become too large to pass.

According to the NKF, the most common symptoms of kidney stones include:

  • Intense and severe pain on the side of your lower back
  • Generalized pain in your stomach and torso
  • Blood in your urine
  • Sudden nausea or vomiting
  • Sudden fever and chills
  • Cloudy urine
  • Strong odor in your urine

If you suspect you have some or all of these symptoms, visit an emergency room or urgent care clinic immediately.

Your healthcare team will likely do a “high-resolution CT scan” or “KUB x-ray” in order to see the exact size, shape, and location of your stone.

 

Causes of kidney stones

The most common causes of “calcium oxalate” or “uric acid” kidney stones are fairly simple — which means preventing them is doable, but for those with diabetes, it can be a bit trickier.

A combination of just a few of these not-so-healthy habits can significantly increase your risk of kidney stones. 

 

Why people with diabetes have a higher risk of developing kidney stones

Well, you already know that consistently high blood sugars can lead to nephropathy (kidney disease), but kidney stones are an additional issue that people with diabetes can develop.

High blood sugars lead to higher acidity in your urine

The higher your blood sugars are, the more acidic your blood and urine become. This acid leads to the development of “uric acid stones.”

Research from European Urology found that patients with type 2 diabetes whose HbA1c levels were over 6.5 percent had a 92 percent higher risk of developing kidney stones. 

Additionally, patients with type 2 diabetes taking insulin with an HbA1c between 5.7 and 6.4 percent faced a 34 percent higher risk of kidney stones. 

In general, patients in the study with fasting blood sugar levels consistently over 126 mg/dL, were 28 percent more likely to develop kidney stones compared to patients with normal fasting blood sugar levels.

The study also reported a significant finding that the main ingredient in kidney stones of people with type 2 diabetes was uric acid compared to the most common type of stone in the non-diabetic population, calcium oxalate.

 

Insulin resistance increases the likelihood of kidney stones

Other research has found a direct relationship between insulin resistance and kidney stones. 

“Insulin resistance plays a key role in type 2 diabetes mellitus,” explains a study published in Reviews in Urology, “and it has been linked to uric acid stone formation. Insulin resistance might result in a deficit in ammonium production in the kidney, which lowers urinary pH, thus generating a favorable milieu for uric acid stone formation.”

Another study, published Advanced Biomedical Research, came to the same conclusion.

“Insulin resistance, characteristic of the metabolic syndrome and type 2 diabetes, results in lower urine pH through impaired kidney ammoniagenesis,” explains the study. 

Insulin resistance and high blood sugars seem to significantly lower the pH in the urine, which is the main influencer of the development of a uric acid stone. This makes the urine in some people with type 2 diabetes an ideal environment for the formation of kidney stones.

 

Treatment options

Fortunately, kidney stones are treatable, but the right treatment for you will depend on the type, location, and size of your stones.

Here are the common treatment options for calcium oxalate and uric acid kidney stones, according to the National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK):

Meet with a urologist 

A urologist specializes in the health and treatment of conditions involving your bladder and urinary tract.

Since kidney stones are largely related to your urine, you’ll likely meet with a urologist rather than a nephrologist (who specializes in kidney health). Your urologist will use the KUB x-ray mentioned earlier to assess the size and location of your stone to then determine the best treatment path.

Shock wave lithotripsy 

This painless treatment “blasts” the kidney stone into smaller pieces so they can be more easily passed through your urine. They may be small enough to pass without much pain or effort.

Even though the shock wave treatment itself isn’t painful, some patients still receive anesthesia during the procedure. The recovery period for this treatment is also brief. You’ll be walking on your own immediately after the procedure, and need a day or two to recuperate at home before resuming your normal physical activity. 

 

Cystoscopy and ureteroscopy 

This treatment involves a “cystoscope” to look inside your urethra and bladder in order to locate the stone. Then your doctor will break it into smaller pieces to pass through your urine, or they’ll remove the stone entirely right then.

This outpatient procedure can be uncomfortable and you will be under anesthesia, but able to go home the same day.

Percutaneous nephrolithotomy

Similar to a cystoscopy, this treatment uses a nephroscope to locate and then remove the kidney stone.

This process is more invasive because the device is inserted directly into your kidney through a small cut in your back. For larger stones, a laser can be used to break them into smaller pieces, making them more passable.

This procedure definitely requires anesthesia and staying in the hospital for a couple of days after the procedure.

Ureteral stent

After any of these treatment options, your urologist may decide to place a thin, flexible tube in your urinary tract. This “ureteral stent” helps your urine and any remaining stones pass more easily.

Your urologist will also likely want to collect the stone in order to examine it and determine what it’s made of. This helps diagnose exactly which type of kidney stone you developed. 

Don’t be surprised if your doctor also asks for a 24-hour urine collection after your stones have been removed. This is to assess how much urine you’re producing during a normal day and to measure the chemicals and minerals present in your urine.

Again, too little fluid and too many minerals can both easily lead to the formation of stones.

 

Prevention

If you’ve experienced kidney stones before, chances are high that you’ll develop them again — unless you make an effort to prevent them. 

“Those who have developed one stone are at approximately 50% risk for developing another within 5 to 7 years,” explains the NKF.

Here are a few things anyone can do to prevent the development of kidney stones:

Improve your blood sugars

Easier said than done, but it’s the most impactful thing you can do to protect your kidneys — let alone the rest of your body. If you don’t work with your healthcare team to bring your blood sugar levels down to a healthy range, you’ll continue to struggle with uric acid kidney stones.

Drink more water

This one is easy — but if you aren’t used to drinking plain water, the pain of a kidney stone may finally motivate you. Skip the diet soda and other chemical-laden beverages, and get more real water into your body every single day. Eventually, you’ll start to crave it.

Eat more vegetables and fruit

Low pH and high acidity levels in your urine can be easily improved by eating more vegetables and fruits. These wholesome real foods are critical to maintaining a healthy balance of pH and acidity in your bloodstream and your urine. As if you need another reason to eat more veggies.

Dark green vegetables also contain a great deal of calcium — which helps to prevent the calcium oxalate type of stones.

Reduce your sodium intake

“Everyone thinks of salty potato chips and French fries,” says the NKF. “Those should be rarely eaten. There are other products that are salty: sandwich meats, canned soups, packaged meals, and even sports drinks.”

How much of your diet consists of highly-processed sodium-laden foods? Adding salt to whole vegetables isn’t nearly as big of a problem as a diet full of these processed foods that rely on excessive sodium to give and maintain its flavor. 

 

Watch your animal protein intake

Animal protein has its place in the human diet, but too much of it can increase the acidity in your blood and urine tremendously.

In fact, low-carb and ketogenic diets are common causes of ketones because of their focus on animal protein. At the end of the day, it comes back to balance

Get enough calcium

While the most common type of kidney stone is referred to as a “calcium oxalate” stone, that doesn’t mean it’s the result of eating too much calcium. 

“Dairy products have calcium, but they actually help prevent stones, because calcium binds with oxalate before it gets into the kidneys,” explains the NKF. 

“People with the lowest dietary calcium intake have an increased risk of kidney stones. A stone can form from salt, the waste products of protein, and potassium.” 

Once again, good habits lead to good health! 

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