High blood pressure drug slows diabetes

Calcium channel blockers used to treat high blood pressure may reverse beta cell death and slow the progress of diabetes, according to a research study from the University of Alabama at Birmingham.

The researchers studied the drug verapamil on human pancreatic islet cells and diabetic mice. They found that verapamil inhibits expression of a protein called TXNIP (thioredoxin-interacting protein) within beta cells.

Past studies showed that high blood glucose turns on the gene for TXNIP, which in excess can signal beta cells to self destruct. Other studies show that lowering TXNIP levels can reduce damage caused by a heart attack.

The current research showed that treatment with verapamil stabilized normal blood glucose levels in the diabetic mice and reduced TXNIP levels by 80 percent. Without verapamil, the control mice experienced raised glucose levels.

In cell studies, researchers found a 50 percent reduction in TXNIP gene expression.

The pancreas has clusters of cells called the islets of Langerhans. These are made up of cells including beta cells that make insulin. Insulin is a hormone that helps the body use glucose for energy. In type 2 diabetes, a person has insulin resistance and had declining insulin production.

“We long have felt that finding an oral medication that inhibits beta cell TXNIP expression would represent a major breakthrough, and now we have the first study sowing that a drug already proven safe in years of clinical practice may halt the development of diabetes,” said Anath Shalev, MD, senior author of the paper.

“Our results are encouraging because patients with diabetes suffer from beta cell death as part of their disease, there has been no treatment targeting this problem and TXNIP-inhibition promises to reverse it,” said Shalev.

In addition, researchers also found that verapamil countered insulin resistance. They theorize that lowering TXNIP levels increases glucose uptake in muscle and fat tissues targeted by insulin.

Diabetes and hypertension
People with type 2 diabetes are twice as likely to develop high blood pressure as those without diabetes, according to the National Institutes of Health (NIH).

About 60 to 65 percent of people with diabetes also have high blood pressure. African Americans are more likely than whites to develop both diseases.

Diabetes is a major risk factor for stroke, and the addition of high blood pressure significantly increases that risk.

Improving blood pressure control in people with type 2 diabetes significantly reduces their risk for diabetes-related death, according to the United Kingdom Prospective Diabetes Study.

The NIH recommends eating foods to control blood sugar and salt intake, getting 30 to 45 minutes of physical activity most days, quitting smoking, limiting alcohol intake, losing weight as needed, and taking prescribed medications.

Sources: University of Alabama at Birmingham, National Institutes of Health