beta blockers and glucose

Last reviewed 12/2022

Betal 2 Receptors have an important role in hepatic glucose production in humans and may contribute to hypoglycemia associated with unselective beta-blockade (1) e.g. use of propranolol rather than the use of beta-1 selective blockers e.g. atenolol, metoprolol.

  • beta -2-adrenergic antagonism has a role in the inhibition of hepatic gluconeogenesis

  • therefore was believed that selective beta-1 blockers would not lead to hypoglycaemia - however "...in patients with abnormal energy requirements or metabolism, administration of beta 1-selective-adrenergic antagonists may be associated with hypoglycaemia..."(2)

Beta blockers in diabetes and insulin resistance:

  • studies, such as the Losartan Intervention for Endpoint Reduction in Hypertension Study (LIFE) (3) with atenolol, the Carvedilol or Metoprolol European Trial (COMET) (4) with metoprolol have shown a 22% to 28% increase of new-onset diabetes with traditional beta beta-blockers that can increase insulin resistance (and hence hyperglycaemia) (5)
  • side effects of beta -blockers in the patient with diabetes include increased insulin resistance with worsening glycemic control
  • increased frequency of hypoglycemia and its lack of recognition can also be a problem in the insulin-deficient patient but is a minimal problem with the patient with type 2 diabetes (5)
  • there is evidence that some beta-blockers may have 'insulin-sensitising properties' (5)
    • carvedilol, a nonselective beta-blocker had vasodilating and insulin-sensitizing properties, and is the ideal beta-blocker for the patient with diabetes (5)
    • carvedilol is a third generation beta-blocker in comparison with atenolol which is a second generation beta blocker

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