Betablocker treatment in diabetes mellitus

Betablockers have been convincingly shown to reduce total and cardiovascular morbidity and mortality of hypertensive diabetic patients. In diabetic patients, after myocardial infarction, these agents confer a twice as high protective effect when compared to non-diabetic patients. However, most paradoxically, betablocking agents are used less frequently in diabetes. Control of hypertension is insufficient in most of the diabetic patients, probably because a combination of antihypertensive agents including betablockers is frequently needed to sufficiently control blood pressure but is not used in these patients. The fear of betablocker-associated side effects in diabetes may be partly responsible for the frequent antihypertensive mono-therapy and the resulting poor quality of blood pressure control among diabetic patients.

We have performed an analysis of the literature to assess whether possible adverse metabolic effects, a higher risk of hypoglycaemia or less nephroprotective effects of beta1-selective betablocking agents could justify the reticence in prescribing these antihypertensive agents to diabetic patients.

A thorough review of the literature does not indicate that beta1-selective betablocking agents have important adverse effects on glucose metabolism, prolong hypoglycaemia or mask hypoglycaemic symptoms. In diabetic nephropathy, betablockers are as nephroprotective as angiotensin converting enzyme inhibitors.

The unnecessary less frequent prescription of beta1-selective betablockers in diabetes mellitus may contribute to the higher cardiovascular mortality among these patients.