Type 2 Diabetes and Beta-Blockers, What You Should Know
When you think about risk factors for type 2 diabetes, obesity, high blood pressure, and inactivity may come to mind. One lesser known factor is use of beta-blockers, but not all of the drugs in this class may raise the chances of developing type 2 diabetes.
Some beta-blockers increase diabetes risk
Beta-blockers (aka, beta-adrenergic blocking agents or beta antagonists) have been on the market for about six decades. The first clinically beneficial beta-blocker to enter the market was propranolol, which was prescribed to treat angina pectoris, a condition in which the heart's need for oxygen exceeds the available supply.
Since then, propranolol and other beta-blockers have been developed and prescribed most often for arrhythmias (abnormal heart rhythms), atrial fibrillation (irregular heart rhythms), high blood pressure, and heart attack, and less often for migraines, anxiety, overactive thyroid, and glaucoma. Beta-blockers work by slowing the heart beat and reducing contractions of blood vessels in the heart, brain, and throughout the body.
According to cardiologist Ragaendra R. Baliga at The Ohio State University Wexner Medical Center, "Studies show that older beta- blockers can increase a patient's risk of type 2 diabetes by more than 25 percent." While raising the risk of diabetes is not good for anyone, it is especially damaging for individuals who already have conditions that affect the heart and vascular system.
In a recent issue of Heart Failure Clinics, Baliga explained that "older beta-blockers are doubled-edged swords. They save lives, but you want to avoid complications down the road, like diabetes." When some beta-blockers are used for a long time, they may have a negative impact on insulin sensitivity and lipid profiles, as well as cause weight gain, all risk factors for diabetes.
Among the older beta-blockers are atenolol (Tenormin), metoprolol (Lopressor), and propranolol (Inderal LA). Baliga noted that when patients have no other limitations, he considers prescribing newer beta-blockers, such as carvedilol (Coreg), rather than the older drugs. Recent research has suggested carvedilol may improve the efficiency of insulin and thus help prevent diabetes.