A drug used primarily to treat high blood pressure appears to prevent the loss of insulin-producing pancreatic beta cells among people with diabetes.
“Broadly speaking, any approach to preserving beta cells is much needed,” Dr. Joshua D. Miller, medical director of diabetes care for Stony Brook Medicine in New York and an assistant professor of endocrinology and metabolism in the school’s Department of Medicine, told Healthline.
Pancreatic beta cells play a role in both type 1 diabetes, an autoimmune disease often called juvenile diabetes, and type 2 diabetes, which is an acquired illness caused by obesity, lack of exercise, and other factors.
In type 1 diabetes, the body’s immune system progressively destroys the insulin-producing beta cells, limiting or ending the ability to metabolize sugars.
People with type 2 diabetes still make insulin, but their body loses the ability to use it effectively. Eventually, the pancreas can’t make enough insulin to keep up with metabolic need.
Over the course of more than a decade and a half of research, Dr. Anath Shalev and colleagues at the University of Alabama at Birmingham School of Medicine discovered that a beta-cell gene called TXNIP played an important role in the body’s response to high glucose levels.
These roles included inhibiting production of the protein thioredoxin, which other research found prevented the death of beta cells.
Later, animal studies conducted by Shalev demonstrated that TXNIP levels could be manipulated to control beta-cell death and, by extension, insulin production and blood sugar levels.
The researchers then began experimenting with verapamil, a blood pressure medication known to reduce the level of TXNIP in heart cells.
That led to the new study with human subjects, which concluded that giving people who recently developed diabetes a daily dose of verapamil improved beta-cell functioning, reduced the need for insulin therapy, and was associated with fewer incidents of hypoglycemia, or dangerously low blood sugar.
“The patients on verapamil retained more of their own insulin production and required less of an increase in their daily insulin (over time),” Shalev told Healthline.
Verapamil wouldn’t be a substitute for injected insulin or an insulin pump, she noted.
Instead, it would be an adjunct therapy, perhaps combined with treatment to prevent the immune response against beta cells.
The placebo-controlled, double-blind phase II trial focused on adults ages 18 to 45 who had developed type 1 diabetes within the previous three months.
Shalev noted that no current diabetes treatment available has been able to similarly prevent destruction of pancreatic beta cells.
Current treatments only replace insulin that the body can’t produce.
Researchers found that verapamil was able to fully “rescue” lab mice from diabetes. Shalev cautioned, however, that it’s unlikely that the same will be true of people.
“The regenerative capability of mice is so much greater than it is for humans,” Shalev said.
Diabetes symptoms and diagnosis typically occur when the body’s ability to produce insulin falls below 20 percent of normal.
“Especially in the first year, the loss of beta cells is rapid, so if we can just stop that attrition, it would be a big gain,” Shalev said.
Miller said that a drug like verapamil would be especially effective if administered earlier in the progression of the disease.
“If we can identify people with type 1 diabetes and give them verapamil to protect their beta cells from immune system destruction, it could prevent them from becoming totally insulin deficient, which most people with type 1 eventually do,” he said.
Miller added that doctor could “ease [people with diabetes] much more gently into their diagnosis,” rather than dealing with it at a crisis stage as is more the norm.
Miller said that people need to be aware of the “Four T” symptoms of type 1 diabetes: Toilet (frequent urination), Thirsty, Tired, and Thinner (unexplained weight loss).
He expressed hope that other researchers will successfully develop an easy and affordable screening test for the disease, which has thus far proven “somewhat elusive.”
“If we can screen and treat patients who have not had much beta-cell destruction yet, that would be the best-case scenario,” Miller said.
Shalev said further research is needed to determine whether long-term verapamil treatment could result in regained ability to produce insulin naturally.
In addition, researchers need to determine if the drug — which is well-tested, safe, and inexpensive — can be used on children with diabetes, adults who’ve had diabetes for years rather than months, and those with type 2 diabetes.
“The research is very interesting in terms of verapamil’s impact on type 1 diabetes, and should be explored for type 2, which is also a progressive disease, to see if that progression can be delayed,” said Miller.
He noted that researchers will have to determine whether verapamil affects the autoimmune response — which is linked to type 1 diabetes only — or some broader mechanism that could make it effective against both types of the disease.