Kidney stones or nephrolithiasis are small pebble-like pieces of material that form in one or both of your kidneys from minerals in the urine. While most kidney stones exit the body without the help of a doctor, some stones get caught in the urinary tract where they can block the flow of urine and cause great pain.
Kidney stones come in several types. The most common are uric acid stones, calcium oxalate stones, and infectious stones.
People with diabetes or metabolic syndrome are particularly susceptible to developing uric acid kidney stones.
One reason why people with diabetes have a higher chance of having a kidney stone is that they often have highly-acidic urine, which puts them at risk for developing uric acid stones. Behind this acidic urine is poorly controlled diabetes.
“When the body doesn’t have enough sugar for metabolism because either it isn’t producing insulin or not responding to insulin it’s forced to metabolize fat and that can make your urine acidotic,” says Phillip Mucksavage, MD, director of endourology and stone disease at Pennsylvania Hospital in Philadelphia. “This condition, called ketoacidosis, can change levels of the pH in urine.”
Diabetes patients also have more calcium oxalate stones than the general population. Once again, uncontrolled diabetes is the culprit.
“Uncontrolled diabetes can cause dehydration which is a prime risk factor for calcium oxalate stones,” says Dr. Mucksavage.
Other diseases such as high blood pressure and obesity may also increase the risk of developing kidney stones.
About 10% of people with kidney stones never know that they have them, since the stones may be too small to cause symptoms or haven’t moved into the bladder, says Dr. Mucksavage. In other cases, when the kidney stone becomes trapped in the urinary tract, pain can be intense. Patients may experience a sharp pain in the back, side, lower abdomen or groin and may have blood in the urine. Other symptoms can include nausea and vomiting, a constant need to empty the bladder, pain upon urination and difficulty urinating.
Knowing the type of stone can help guide treatment. To detect kidney stones, doctors may order lab tests to look for urine in blood, signs of infection, minerals (like calcium), and stones. Blood tests can detect high levels of certain minerals.
CT scans or X-ray imaging can aid in pinpointing the location and size of a kidney stone. Depending on the results, patients may be prescribed medicine, such as potassium citrate that can lessen the acidity of the urine and advised to drink a lot of fluids. Or, a procedure might be used to break up or remove the kidney stone. These include a method that delivers shock waves to the stone from outside the body or inserting a tool into the body– either through the urinary tract or directly into the kidney through surgery. Once the stone is located, it can be broken into smaller pieces. Once you’ve had a kidney stone, you have an increased chance of having another.
“The general recommendation for people with diabetes is to keep their sugars low and to stay hydrated,” says Dr. Mucksavage. “The more hydrated you are, the fewer stones you will form.”
Although some sources recommend a low oxalate diet to avoid calcium oxalate kidney stones, in reality, this is very hard to do, says Dr. Mucksavage, since oxalate is in virtually every food. Instead, he recommends that patients follow a DASH or healthy heart diet, even if it includes leafy greens high in oxalate. He also suggests that people with diabetes who have had kidney stones to speak to a urologist about how to prevent future problems.
Gallstones & Type 2 Diabetes
“People with diabetes, metabolic syndrome, high triglycerides, and obesity are at a high risk for having gallstones,” said Leann Olansky , MD an endocrinologist at the Cleveland Clinic. “People with diabetes are at a three-fold risk of gallbladder diseases compared with those without diabetes. And they tend to develop gallstones at an earlier age .”
The gallbladder is a small pear-shaped hollow organ located in the upper right abdomen below the liver. It holds bile, a yellow-green fluid made by the liver that aids in fat digestion. As your stomach and intestines digest food, the gallbladder releases bile through a tube called the common bile duct.
Gallstones–which can be as small as a grain of sand or as large as a golf ball--are caused by an imbalance in the substances that compose bile and form if bile hardens. Problems occur if a gallstone blocks the common duct, preventing the bile from reaching the intestines, or form in the gallbladder, not allowing it to empty when bile is needed.
Insulin resistance can cause gallstones.
“In the case of insulin resistance excess carbohydrates are converted into triglycerides (or fats),” says Dr. Olansky. “You can end up with more fats than your liver can process. These fats, particularly saturated fats, interfere with gallbladder function and raise the chance of developing gallstones.”
Other causes of gallstones include rapid weight loss, obesity, and diets high in carbohydrates. Women are much more likely than men to develop gallstones. Gallstones occur in nearly a quarter of women in the U.S. by age 60, and as many as half by age 75. In most cases, they have no symptoms. In general, women are probably at increased risk because estrogen stimulates the liver to remove more cholesterol from the blood and divert it into the bile.
Gallstones can be found by chance on an abdominal x-ray or ultrasound done for other reasons, but unless there are symptoms of pain, nausea, vomiting or fever, no further intervention or testing may be needed.
Symptoms arise when a gallstone blocks the flow of bile from the gallbladder or through the bile ducts. Pain in the bile duct is often located in the upper abdomen and can radiate to the right shoulder or between the shoulder blades. Sweating, nausea, particularly after eating a fatty meal, and vomiting can occur.
If the gallbladder is inflamed, with infected material trapped within the common bile duct or a stone blocking the outflow of pancreatic juice patients can have fever, chills, severe abdominal pain or jaundice. This can signal gallstone pancreatitis, an inflammation of the pancreas that results from blockage of a common duct shared by the pancreas and gallbladder by a gallstone and requires immediate medical attention.
Doctors commonly use an abdominal ultrasound exam to detect gallstones in the gallbladder or common bile duct.
Treatment for gallstones that obstruct the common bile duct is endoscopic retrograde cholangiopancreatography (ERCP) or surgery. ERCP involves passage of a thin flexible scope through the mouth and into the duodenum where it is used to evaluate the common bile duct or pancreatic duct. Tiny tubes and instruments may be employed to evaluate the ducts and remove stones if necessary. Gallbladder surgery may be performed if stones are found in the gallbladder itself, as these cannot be removed by ERCP. This operation, known as cholecystectomy, is frequently done using a laparoscope and is inserted into the abdomen through several small incisions under general anesthesia.
If a gallbladder operation is not possible, a medicine known as ursodiol may be used to dissolve cholesterol gallstones but this can take months, and the stones recur in many people once the treatment is stopped.
To prevent gallstones Dr. Olansky recommends that people with diabetes should work to control their sugars and consume a healthy diet that stresses “good” fats, such as mono-saturated or omega-3 fats and limit refined carbohydrate consumption.