It was traditionally believed that some drugs used to treat high blood pressure might cause diabetes. Previous research has suggested that beta-blockers and other drugs called thiazide diuretics may lead to diabetes. However the results of a new study show that beta-blockers are the only blood pressure drugs linked to the disease.
Potential mechanisms by which beta-blockers may contribute to the development of diabetes include weight gain, attenuation of the beta-receptor-mediated release of insulin from pancreatic beta cells, and decreased blood flow through the microcirculation in skeletal-muscle tissue, leading to decreased insulin sensitivity.
The results are based on a study of more than 12,000 people aged 45 to 64 who did not have diabetes. At the start of the study, participants underwent a physical examination, which included blood pressure measurements and an interview about the medications they were taking.
The study also found that just having high blood pressure more than doubles a person's risk of developing type 2 diabetes, which usually begins in adulthood. Interestingly, the data from both short-term and long-term studies indicate that ACE inhibitors may actually improve insulin sensitivity and decrease the risk of type 2 diabetes.
The New England Journal of Medicine 2000;342:905-912, 969-970
This is a great study that helps clear up some of the confusion about drugs and the risk of diabetes. I had always told patients that most water pills (thiazide diuretics) increase the risk of diabetes. This does not appear to be the case, but the beta blockers (drugs like Inderal and Tenormin) increase the risk by nearly 30 percent.
However, the cardiovascular benefits of the beta-blockers might outweigh the risk of diabetes for some people. Plus, beta-blockers are very inexpensive, which makes them an important option for people who cannot afford other medications.
Beta-blockers should still play an important role in the treatment of people with high blood pressure and heart disease and even in those with high blood pressure and diabetes, who are particularly at risk for heart disease. They are particularly good for high anxiety people who are very stressed out.
HOWEVER, they are clearly NOT the long-term option. They don't address the reason one developed high blood pressure. The reason the study found that high blood pressure doubled a person's risk of diabetes is that the same thing that causes type 2 diabetes causes most high blood pressure problems.